Saturday, December 31, 2005

Tobramycin (Ophthalmic)

Description Return to top

Ophthalmic tobramycin (toe-bra-MYE-sin) is used in the eye to treat bacterial infections of the eye. Tobramycin works by killing bacteria.

Ophthalmic tobramycin may be used alone or with other medicines for eye infections. Either the drops or the ointment form of this medicine may be used alone during the day. In addition, both forms may be used together, with the drops being used during the day and the ointment at night.

Tobramycin ophthalmic preparations are available only with your doctor's prescription, in the following dosage forms:

Ophthalmic

Ophthalmic ointment (U.S. and Canada)
Ophthalmic solution (eye drops) (U.S. and Canada)

Before Using This Medicine Return to top

In deciding to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For ophthalmic tobramycin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to ophthalmic tobramycin or to any related medicines, such as amikacin (e.g., Amikin), gentamicin (e.g., Garamycin), kanamycin (e.g., Kantrex), neomycin (e.g., Mycifradin), netilmicin (e.g., Netromycin), streptomycin, or tobramycin by injection (e.g., Nebcin). Also tell your health care professional if you are allergic to any other substances, such as preservatives.

Pregnancy—Studies have not been done in humans. However, tobramycin ophthalmic preparations have not been shown to cause birth defects or other problems in animals even when given at high doses.

Breast-feeding—Tobramycin ophthalmic preparations may be absorbed into the eye. However, tobramycin is unlikely to pass into the breast milk in large amounts and little would be absorbed by the infant. Therefore, this medicine is unlikely to cause serious problems in nursing babies.

Children—This medicine has been tested in children and, in effective doses, has not been shown to cause different side effects or problems than it does in adults.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of ophthalmic tobramycin in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are using any other prescription or nonprescription (over-the-counter [OTC]) medicine that is to be used in the eye.

Proper Use of This Medicine Return to top

For patients using tobramycin ophthalmic solution (eye drops):

The bottle is only partially full to provide proper drop control.

To use:

First, wash your hands. Tilt the head back and with the index finger of one hand, press gently on the skin just beneath the lower eyelid and pull the lower eyelid away from the eye to make a space. Drop the medicine into this space. Let go of the eyelid and gently close the eyes. Do not blink. Keep the eyes closed for 1 or 2 minutes, to allow the medicine to come into contact with the infection.

If you think you did not get the drop of medicine into your eye properly, use another drop.

To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). Also, keep the container tightly closed.

If your doctor ordered two different ophthalmic solutions to be used together, wait at least 5 minutes between the times you apply the medicines. This will help to keep the second medicine from ``washing out'' the first one.

For patients using tobramycin ophthalmic ointment (eye ointment):

To use:

First, wash your hands. Tilt the head back and with the index finger of one hand, press gently on the skin just beneath the lower eyelid and pull the lower eyelid away from the eye to make a space. Squeeze a thin strip of ointment into this space. A 1.25-cm (approximately ½-inch) strip of ointment usually is enough, unless you have been told by your doctor to use a different amount. Let go of the eyelid and gently close the eyes and keep them closed for 1 or 2 minutes, to allow the medicine to come into contact with the infection.

To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). After using tobramycin eye ointment, wipe the tip of the ointment tube with a clean tissue and keep the tube tightly closed.

To help clear up your eye infection completely, keep using tobramycin for the full time of treatment, even if your symptoms have disappeared. Do not miss any doses.

Dosing

The dose of ophthalmic tobramycin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average dose of ophthalmic tobramycin. If your dose is different, do not change it unless your doctor tells you to do so.

The number of doses you use each day, the time allowed between doses, and the length of time you use the medicine depend on the medical problem for which you are using ophthalmic tobramycin.

For ophthalmic ointment dosage forms:

For mild to moderate infections:

Adults and children—Use every eight to twelve hours.

For severe infections:

Adults and children—Use every three to four hours until improvement occurs.
For ophthalmic solution (eye drops) dosage forms:
For mild to moderate infections:
Adults and children—One drop every four hours.

For severe infections:

Adults and children—One drop every hour until improvement occurs.

Missed dose

If you miss a dose of this medicine, use it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.

Storage

To store this medicine:

Keep out of the reach of children.
Store away from heat and direct light.
Keep the medicine from freezing.
Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Precautions While Using This Medicine Return to top

If your eye infection does not improve within a few days, or if it becomes worse, check with your doctor.

Side Effects of This Medicine Return to top

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

Itching, redness, swelling, or other sign of eye or eyelid irritation not present before use of this medicine

Symptoms of overdose

Increased watering of the eyes; itching, redness, or swelling of the eyes or eyelids; painful irritation of the clear front part of the eye

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if either of the following side effects continues or is bothersome:

Less common

Burning or stinging of the eyes

Eye ointments usually cause your vision to blur for a few minutes after application.
Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Brand Names Return to top

In the U.S.—

AKTob
Tobrex

In Canada—
Tobrex

Category Return to top

Antibacterial, ophthalmic

Medline Plus

Tuesday, December 20, 2005

New Strategies Take on Antibiotic Resistance

Virtually all disease-causing bacteria eventually acquire the ability to resist the antibiotic drugs used to treat them. First encountered in hospital patients, antibiotic resistance is spreading at a rapid rate, making some infections more difficult to treat. Recently, scientists supported by the National Institute of General Medical Sciences (NIGMS) have devised creative new strategies to address the problem of antibiotic resistance.

Disarming the Microbes

One solution to the resistance problem is to develop new classes of antibiotics, but these could follow in their predecessors’ footsteps and in time lose their effectiveness. In a different approach, chemists supported by NIGMS have found a way to make bacteria vulnerable to existing antibiotics again.

Bacteria frequently acquire antibiotic resistance by ingesting circular pieces of DNA called plasmids. These plasmids often encode proteins that bacteria can use to thwart the effects of antibiotics. Plasmids are widespread and bacteria readily share them—even with bacteria that cause different diseases. That’s why antibiotic resistance happens so quickly.

The researchers, led by Paul Hergenrother, Ph.D., of the University of Illinois at Urbana-Champaign, have taken advantage of a natural phenomenon called plasmid incompatibility. Incompatible plasmids do not coexist in a bacterial cell because they compete for the same resources and the “stronger” plasmid promptly evicts the “weaker” one. By mimicking this process using a small molecule called apramycin the scientists forced bacteria to expel their resistance-carrying plasmids, effectively re-sensitizing the bacteria to an antibiotic.

Apramycin is probably too toxic to use in people, but Hergenrother is applying the same principle to develop compounds that could be medically useful. Though still in the early stages, this approach holds promise as an effective strategy for combating antibiotic resistance.


Needling Bacteria into Submission

Most antibiotics kill bacteria by fouling up a key biochemical process within bacterial cells. The drugs typically accomplish this by slipping into the bacterial cell and latching onto a key protein, hampering its function. In response, bacteria have come up with myriad ways to evade the drugs’ actions. Many use pumps to rid themselves of antibiotics, while others launch search-and-destroy molecules into their surroundings, wiping out the drugs before they can enter bacterial cells. Still others change the protein that the antibiotic targets so the antibiotic no longer binds to it. The altered protein is still able to carry out its normal function in the bacterium, even in the presence of the antibiotic.

But over time, bacteria have been largely unable to evade a group of molecules called antimicrobial peptides. These molecules are found in a wide range of organisms, including humans, where they serve as a first-line defense against invading germs. Rather than targeting a specific bacterial protein, antimicrobial peptides physically disrupt an entire cellular structure, the cell membrane, much like a needle popping a balloon. The cell membrane helps protect the bacterium from the outside world.

Scientists believe that bacteria are unlikely to develop resistance toward antimicrobial peptides because the cell membrane is a multi-component structure rather than a single biochemical target. In support of this, scientists have observed little bacterial resistance to the peptides. This makes antimicrobial peptides attractive candidates for development into more potent forms suitable for treating infections.

Early attempts to develop antimicrobial peptides into drugs faltered due to several problems. Although the peptides effectively killed bacteria in test tubes, they did not quell infections in laboratory animals unless administered at very high—often close to toxic—doses. The peptides were also difficult and expensive to produce on a large scale.

Now, research supported by NIGMS points to a way around these problems. Scientists led by William DeGrado, Ph.D., of the University of Pennsylvania in Philadelphia chemically synthesized molecules that mimic the activity of the natural peptides. The synthetic molecules can be produced easily and cheaply, and they exhibit potent and broad antibacterial activity in the test tube.

These encouraging results led DeGrado to help found a pharmaceutical company to develop the synthetic molecules into antibiotic drugs. The company is testing compounds that have already been shown to kill over 50 human pathogens. Some of these compounds have high antibacterial activity and low toxicity in laboratory animals. Importantly, bacteria did not develop resistance to three of the compounds in a widely used laboratory test.

If planned clinical trials in humans are successful, the prospect of a significant new weapon in the war on bacterial infection may soon become a welcome reality.


Contact:
Kirstie Saltsman, NIGMS

saltsmank@nigms.nih.gov

Last Updated November 23, 2005

National Institute of General Medical Sciences

Monday, December 19, 2005

'Stalwart' antibiotics often fail

Antibiotic "stalwarts" like penicillin and amoxicillin do not work in a significant number of cases, US research has suggested.

University of Rochester experts looked at data on almost 11,500 children with a common throat infection.

A quarter of those given penicillin and 18% of those on amoxicillin needed further treatment within weeks.

Scientists told a Washington conference that newer antibiotics should be used more, but a UK expert urged caution.

The data, from an analysis of 47 studies from the past 35 years looking at the effectiveness of various drugs on treating strep throat in children, was presented to the Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington.

The researchers also found that, of those given older-generation cephalosporin antibiotics, 14% had to return for more treatment, while just 7% prescribed newer versions like cefpodoxime and cefdinir, given for just four or five days, had to go back to the doctor.

The results back up previous work by the team, published in Pediatrics last year, which reported the waning effectiveness of penicillin and amoxicillin.

The scientists suggest other bacteria which can be present in the throat can hamper the effectiveness of the drugs.

This happens because many bacteria produce enzymes called beta-lactamase that can inactivate penicillin and amoxicillin.

Strep does not - but it is possible the other bacteria which do are present in the throat and can inactivate a drug before it has a chance to work

'Trade-off"


Professor of microbiology and immunology Michael Pichichero, who led the research team, said: "Most doctors are shocked to learn of the high failure rates of the older medications.

"The treatment paradigm [model] for treating strep sore throats has been changing slowly, and endorsing the use of cephalosporins as a first-line treatment is something that needs to be seriously considered."


He added that most drugs will fail to be effective some of the time, but doctors would view a drug that fails in one out of four patients as unacceptable.


Dr Robert George, director of the Respiratory and Systemic Infection Laboratory and a consultant medical microbiologist for the Health Protection Agency, said: "The World Health Organisation continues to recommend penicillin as the first line of treatment for strep throat and the Health Protection Agency guidance is in accordance with this."


He added: "Although prescribing cephalosporins might reduce a strep throat infection in a shorter time period, the effects of using a more potent antibiotic must be considered."


Dr George warned using the antibiotics more regularly for strep throat could increase the amount of resistance to the medication, potentially reducing its effectiveness against the broad range of bacteria it can target.


BBC News December 19, 2005

Sunday, December 18, 2005

Antibiotics to prevent complications following dental implant treatment

Antibiotics to prevent complications following dental implant treatment

(Cochrane Review)

Esposito M, Coulthard P, Oliver R, Thomsen P, Worthington HV

ABSTRACT

A substantive amendment to this systematic review was last made on 15 March 2003. Cochrane reviews are regularly checked and updated if necessary.


Background:

Some dental implant failures may be due to bacterial contamination at implant insertion. Infections around biomaterials are difficult to treat and almost all infected implants have to be removed. In general, antibiotic prophylaxis in surgery is only indicated for patients at risk of infectious endocarditis, for patients with reduced host-response, when surgery is performed in infected sites, in cases of extensive and prolonged surgical interventions and when large foreign materials are implanted. To minimise infections after dental implant placement various prophylactic systemic antibiotic regimens have been suggested. More recent protocols recommended short term prophylaxis, if antibiotics have to be used. With the administration of antibiotics adverse events may occur, ranging from diarrhoea to life-threatening allergic reactions. Another major concern associated with the widespread use of antibiotics is the selection of antibiotic-resistant bacteria. The use of antibiotics in implant dentistry is controversial. It would be useful to know whether prophylactic antibiotics are effective in reducing failures of dental implants.

Objectives:

To assess the beneficial or harmful effects of the administration of prophylactic antibiotics for dental implant placement versus no antibiotic/placebo administration and if antibiotics are of benefit, to find which type, dosage and duration is the most effective.

Search strategy:

We searched the Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. We handsearched several dental journals. No language restrictions were applied. Personal contacts and manufacturers of dental implants were contacted to identify unpublished trials. Most recent search: March 2003.

Selection criteria:

Randomised controlled clinical trials (RCTs) with a follow up of at least 3 months comparing the administration of various prophylactic antibiotics regimens and no antibiotics/placebo to patients undergoing dental implant placement. Outcome measures were prosthesis failures, implant failures, postoperative infections and adverse events (gastrointestinal, hypersensitivity).

Data collection and analysis:

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were to be conducted in duplicate and independently by two reviewers. Results were to be expressed as random effects models using weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes with 95% confidence interval. Heterogeneity was to be investigated including both clinical and methodological factors.

Main results:

No RCTs were identified.

Authors' conclusions:

There is not appropriate scientific evidence to recommend or discourage the use of prophylactic systemic antibiotics to prevent complications and failures of dental implants. Even though the present review did not assess the effectiveness of prophylactic antibiotics for patients at risk for endocarditis, it seems sensible to recommend the use of prophylactic antibiotics for patients at high and moderate risk for endocarditis, with immunodeficiencies, metabolic diseases, irradiated in the head and neck area and when an extensive or prolonged surgery is anticipated.

Citation:

Esposito M, Coulthard P, Oliver R, Thomsen P, Worthington HV. Antibiotics to prevent complications following dental implant treatment. The Cochrane Database of Systematic Reviews 2003, Issue 3. Art. No.: CD004152. DOI: 10.1002/14651858.CD004152.

The Cochrane Collaboration

Single-dose antibiotics reduce appendectomy complications

Single-dose antibiotics reduce appendectomy complications

Category: Infectious Diseases/Bacteria/Viruses News

Article Date: 21 Jul 2005

A single dose of antibiotics may be just as effective as multiple doses in preventing infections after an appendectomy, a new research review confirms.

Researchers at Bispebjerg Hospital in Copenhagen analyzed 45 controlled clinical trials in which antibiotics to fight wound infections following appendectomies were compared with placebo. Sixteen of the trials also included data on the development of an intra-abdominal abscess, or an infected pocket of pus formed by a ruptured appendix. In all, 9,576 patients were included in the analyses.

The review found that antibiotic injections do work no matter how diseased the appendix was or whether it was diseased at all. This is significant, because some surgeons contend that antibiotics should be used only when the appendix is at a more advanced stage of disease.

The study also indicates that a single antibiotic dose has the same impact as multiple doses, and that if multiple doses are used, it does not matter whether they are given before, during or after the operation.

The study appears in the July issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that produces systematic reviews of healthcare interventions, based on the content and quality of existing clinical trials on the topic.

"I don't think that there is any controversy any longer about whether antibiotics work," says co-author Henning Andersen, Ph.D. "What we need to focus on now are factors such as dosage, administration time and length of administration. Why give patients a lot of antibiotics if just one shot could help prevent wound infection or abscess?"

Andersen says that the most important reason for giving a single dose rather than multiple doses is to prevent the development of antibiotic resistance. "Cost is not really a factor," says Andersen. "Antibiotics are fairly inexpensive drugs, so it's not from an economic point of view that you should reduce their use. You should reduce their use so that you won't develop resistance."

Timothy Babineau, M.D., associate professor of surgery at the Boston University School of Medicine, says that all surgeons now use antibiotics for appendectomies but how they use them varies enormously. "Practitioners are all over the map on this," he says. "They tend to practice the way they were taught."

Babineau is skeptical about whether a single antibiotic dose would be sufficient in all cases. "The problem now is that we're under so much pressure to limit our antibiotic usage in all diseases because of the problems with resistant strains of organisms," he says. "I think perhaps we may be seeing the pendulum swing too far in the wrong direction, where patients are not receiving adequate antibiotic coverage. A decade or even five years ago, the opposite was true."

The authors first published a review of antibiotic use during appendectomies in 2001 and then updated it in 2003. This 2005 paper is the second time that the review has been updated.

Appendicitis is the most common cause of acute abdominal pain requiring surgery. The overall lifetime risk for acute appendicitis is between 6 percent and 20 percent but occurs most frequently in adolescents. The incidence of appendicitis in children and in adults past the age of 70 years is small.

The review was funded by the Danish Pharmacy Foundation of 1991, the Danish Institute for Health Technology Assessment, and the Copenhagen Hospital Corporation.

Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. The Cochrane Database of Systematic Reviews 2005, Issue 3

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions.

Visit Cochrane Collaboration for more information.

Betina Andersencccg@cccg.dk

Center for the Advancement of Health

Saturday, December 17, 2005

Antibiotic-associated diarrhea

Overview

Antibiotics first came into general use during World War II. Every American soldier was issued a first-aid kit containing sulfa powder, and the Allied forces who stormed Normandy carried penicillin. Since then, antibiotics have saved millions of lives. But like all drugs, antibiotics have side effects. One of the most common is antibiotic-associated diarrhea (AAD) — a potentially serious condition that affects up to 20 percent of people receiving antibiotic therapy.

AAD occurs when antibiotics disturb the natural balance of "good" and "bad" bacteria in your intestinal tract, causing harmful bacteria to proliferate far beyond their normal numbers. The result is often frequent, watery bowel movements.

Most often, the diarrhea is fairly mild and clears up shortly after you stop taking the antibiotic. But sometimes you may develop colitis, an inflammation of your colon, or a more serious form of colitis called pseudomembranous colitis. Both can cause abdominal pain, fever and bloody diarrhea. In cases of pseudomembranous colitis, these symptoms may become life-threatening.

Effective treatments exist for mild AAD, as well as for colitis and pseudomembranous colitis. In addition, taking concentrated supplements of beneficial bacteria (probiotics) may relieve symptoms or help prevent AAD in the first place.

Signs and symptoms

AAD can cause signs and symptoms that range from mild to severe. Most often, you'll have only a slight change in the bacteria in your digestive tract, which can cause loose stools or more bowel movements a day than are normal for you. If you develop these symptoms, they're likely to begin between the fourth and ninth days of therapy and to end within a few days to two weeks after you stop taking antibiotics. Sometimes, however, diarrhea and other symptoms may not appear for days or even weeks after you've finished antibiotic treatment.

When the overgrowth of harmful bacteria is severe, you may have signs and symptoms of colitis or pseudomembranous colitis, such as:

Frequent, watery diarrhea
Abdominal pain and cramping
Fever, often higher than 101 F
Pus in your stool
Bloody stools
Nausea
Dehydration

You may not see an improvement until several weeks after you begin treatment for colitis or pseudomembranous colitis. And sometimes symptoms recur — usually within two months of the initial treatment — which means you may need to be treated a second or even a third time.

Causes

Your digestive tract is a complex ecosystem that's home to millions of microorganisms (intestinal flora), including more than 500 species of bacteria. Many of these bacteria are beneficial, performing essential functions such as synthesizing certain vitamins, stimulating your immune system and helping protect you from harmful viruses and bacteria.

But some of the bacteria that normally inhabit your intestinal tract are potentially dangerous. They're usually kept in check by beneficial bacteria unless the delicate balance between the two is disturbed by illness, medications or other factors.

Antibiotics can be especially disruptive to intestinal flora because they destroy beneficial bacteria along with harmful ones. Without enough "good" microorganisms, "bad" bacteriathat are resistant to the antibiotic you receivedgrow out of control, producing toxins that can damage the bowel wall and trigger inflammation.

The bacterium responsible for almost all cases of pseudomembranous colitis and many instances of severe AAD is Clostridium difficile. A small percentage of healthy people have C. difficile in their digestive tracts, but most people acquire the bacteria during a stay in a hospital or nursing home.

It's likely that many hospitalized patients are exposed to C. difficile, but the bacterium causes problems only in people treated with antibiotics. Then it grows out of control, leading to severe diarrhea and potentially life-threatening complications.

What antibiotics cause AAD?

Virtually any antibiotic can cause AAD, colitis or pseudomembranous colitis, but the most common culprits are ampicillin, amoxicillin and clindamycin. Other antibiotics that have been especially implicated in pseudomembranous colitis include the cephalosporins cefuroxime (Ceftin) and cefpodoxime (Vantin). Sometimes erythromycins (Erythrocin), fluoroquinolones (Cipro, Floxin) and tetracyclines also can cause AAD. Problems can occur whether you take the antibiotics by mouth or receive them by injection.

Other effects of antibioticsIn addition to disrupting the balance of microorganisms in your digestive tract, antibiotics can also affect the following:

Rate of digestion. Antibiotics such as erythromycin can cause food to leave your stomach too quickly, causing nausea and vomiting. Other antibiotics may increase intestinal contractions, speeding up the rate at which food moves through your small intestine and contributing to diarrhea.

Breakdown of food. Antibiotics may affect the way your body metabolizes fatty acids.

Risk factors

Anyone who undergoes antibiotic therapy is at risk of AAD. But you're more likely to develop problems if you:

Are an older adult
Have had surgery on your intestinal tract
Have recently been in a hospital or nursing home, especially for several weeks

When to seek medical advice

Call your doctor right away if you experience the following signs and symptoms:

Several episodes of loose stools or watery diarrhea for two or more consecutive days

Fever
Abdominal pain or cramping
Pus or blood in your stool

These signs and symptoms may indicate a number of conditions, ranging from viral, bacterial or parasitic infections to inflammatory bowel disorders such as ulcerative colitis or Crohn's disease. In older adults with cardiovascular disease, low blood flow to the colon (ischemic colitis) also can cause these symptoms.

But if you're currently taking antibiotics or have recently finished antibiotic therapy, it's possible you have AAD. Your doctor can perform tests to determine the exact cause of your symptoms.

Have a serious illness such as cancer

Have a compromised immune system

Screening and diagnosis

To help diagnose AAD, your doctor will ask about your medical history, including whether you've had recent hospitalizations or antibiotic therapy. If your symptoms are severe, you'll also likely be asked to provide samples of your stool.

These are then checked in a laboratory for the presence of C. difficile. In a certain percentage of cases, a stool culture is falsely negative. This means that although C. difficile is present in your intestinal tract, it isn't detected by that test. Repeating the test may provide a more accurate result. You may also have a more sensitive test to check for toxins produced by C. difficile (cytotoxicity assay). Although it takes longer to obtain the results, this test is highly accurate in making the diagnosis.

Complications

Mild AAD isn't likely to cause any lasting problems. But pseudomembranous colitis can lead to life-threatening complications, including:

A hole in your bowel (bowel perforation). This results from extensive damage to the lining of your large intestine. The greatest risk of a perforated bowel is that bacteria from your intestine will infect your abdominal cavity (peritonitis).

Toxic megacolon. In this condition, your colon becomes unable to expel gas and stool, causing it to become greatly distended (megacolon). Signs and symptoms of toxic megacolon include abdominal pain and swelling, fever and weakness. You may also become groggy or disoriented. Left untreated, your colon can rupture, causing bacteria from your colon to enter your abdominal cavity. A ruptured colon requires emergency surgery and in some cases may be fatal.
Dehydration. Severe diarrhea can lead to excessive loss of fluids and electrolytes — substances such as sodium, potassium and chloride that are essential for transmitting nerve impulses, making your muscles contract and maintaining proper levels of fluid in and around your cells. Extreme fluid loss can cause seizures and shock — a condition in which your tissues don't receive enough oxygen. Symptoms of dehydration include a very dry mouth, intense thirst, little or no urination and extreme weakness.

Treatment

If you have mild diarrhea, your symptoms are likely to clear up within a few days to two weeks after your antibiotic treatment ends. In the meantime, your doctor may recommend drinking plenty of liquids to prevent dehydration and avoiding foods that may aggravate your symptoms. When diarrhea is more severe, your doctor may stop your antibiotic therapy and wait for your symptoms to subside.

In cases of very severe diarrhea, colitis or pseudomembranous colitis, you're likely to be treated with the drug metronidazole (Flagyl), which is usually taken in tablet form for 10 days. If metronidazole isn't effective, or you're pregnant or breastfeeding, you'll receive another drug, vancomycin (Vancocin).

Both metronidazole and vancomycin are antibiotics that effectively control C. difficile. Vancomycin was once the drug of choice for treating AAD, but it's now usually reserved for the most resistant cases. It's also recommended for pregnant and lactating women because the effects of metronidazole on fetuses and infants aren't known.

Some people treated for pseudomembranous colitis have a recurrence of symptoms and need further treatment.

ProbioticsThe term probiotic means "for life." It generally refers to concentrated supplements of beneficial bacteria similar to those that occur naturally in your intestinal tract. Most probiotic supplements are formulated to survive the digestive process and the highly acidic conditions in your stomach.

Giving probiotic supplements to children receiving antibiotics can help prevent AAD. But the results of studies on adults have been mixed. Some studies have shown probiotic supplements to be effective in preventing or reducing the symptoms of AAD, while others have not. Anecdotal evidence indicates that instilling probiotics rectally may be more beneficial than taking them orally.

Probiotic formulas are available in liquid and capsule form in drugstores and natural food stores and in some grocery stores. Many need refrigeration. In addition, commercial yogurt labeled as having live cultures contains certain "good" bacteria, such as Lactobacillus acidophilus.
Another probiotic, the yeast Saccharomyces boulardii, has been shown to help protect against pseudomembranous colitis. This yeast, taken orally, is used in Europe to help prevent symptoms of AAD and may also prevent recurrences of the disease.

Capsules of S. boulardii are available in natural food stores and some drugstores. Although S. boulardii rarely causes side effects, avoid it if you have a yeast allergy. And if you have HIV/AIDS, talk to your doctor before trying this product.

Prevention

The following suggestions may help prevent AAD or reduce its severity:

Take antibiotics only when you and your doctor feel it's absolutely necessary. Keep in mind that antibiotics won't help viral infections such as colds and flu.

Use antibiotics exactly as prescribed. Don't increase the dose, double up on missed doses, or take the medication longer than your doctor recommends.

Consider eating yogurt or taking probiotic capsules before, during and after antibiotic treatment.

Self-care

If you develop AAD, colitis or pseudomembranous colitis, these dietary changes may help ease your symptoms:

Drink plenty of fluids. Water is best, but fluids with added sodium and potassium (electrolytes) may be beneficial as well. Avoid carbonated beverages, citrus juices, alcohol and caffeinated drinks such as coffee, tea and colas, which may aggravate your symptoms.

Emphasize soft, bland, easy-to-digest foods. These include rice, plain baked potatoes, yogurt and bananas. It's best to avoid most other fruits and their juices as well as dairy foods because they can make diarrhea worse.

Try eating several small meals. Space meals throughout the day instead of eating two or three large ones. Smaller servings are easier to digest.

Avoid certain foods. Stay away from spicy, fatty or fried foods and any other foods that make your symptoms worse.

Also, check with your doctor first before taking antidiarrheal medications, which may interfere with your body's ability to eliminate toxins and lead to serious complications.

Mayo Clinic

Children Overprescribed Antibiotics for Sore Throat

News From the AMA:

Children Overprescribed Antibiotics for Sore Throat

Nov. 10, 2005 — Physicians prescribe antibiotics for more than half of children with sore throat, exceeding the expected prevalence of strep throat, and used nonrecommended antibiotics for 27 percent of children who received an antibiotic prescription, according to a study in the November 9 issue of the Journal of the American Medical Association.

Pharyngitis (inflammation of the throat) accounts for 6 percent of visits by children to family medicine physicians and pediatricians, according to background information in the article. The most common manifestation of acute pharyngitis is sore throat. The main bacterial cause of sore throat and the only common cause of sore throat warranting antibiotic treatment is group A beta-hemolytic streptococci (GABHS). GABHS are cultured from 15 percent to 36 percent of children with sore throat. To improve diagnostic accuracy and reduce unnecessary antibiotic treatment, it is recommended that a GABHS test be conducted prior to treating children with an antibiotic. Penicillin is the recommended antibiotic, but acceptable alternatives include amoxicillin, erythromycin (for penicillin-allergic patients), and first-generation cephalosporins.

Jeffrey A. Linder, M.D., M.P.H., of Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues conducted a study to determine the change in the rate and type of antibiotics prescribed to children with a chief complaint of sore throat, and the frequency of GABHS testing. The researchers used data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1995 to 2003. The study included an analysis of visits by children aged 3 to 17 years with sore throat to office-based physicians, hospital outpatient departments, and emergency departments (n=4,158), and of a subset of visits with GABHS testing data (n=2,797).


The researchers found that physicians prescribed antibiotics in 53 percent of an estimated 7.3 million annual visits for sore throat and nonrecommended antibiotics to 27 percent of children who received an antibiotic. Antibiotic prescribing decreased from 66 percent of visits in 1995 to 54 percent of visits in 2003. This decrease was attributable to a decrease in the prescribing of recommended antibiotics (49 percent to 38 percent). Physicians performed a GABHS test in 53 percent of visits and in 51 percent of visits at which an antibiotic was prescribed. GABHS testing was not associated with a lower antibiotic prescribing rate overall (48 percent tested vs. 51 percent not tested), but testing was associated with a lower antibiotic prescribing rate for children with diagnosis codes for pharyngitis, tonsillitis, and streptococcal sore throat (57 percent tested vs. 73 percent not tested).


"In conclusion, we found that physicians prescribed antibiotics less frequently over time to children with sore throat. However, the overall antibiotic prescribing rate continues to exceed the expected prevalence of GABHS, and physicians continue to select unnecessarily broad-spectrum antibiotics. Unnecessary antibiotic prescriptions are not benign: they increase the prevalence of antibiotic-resistant bacteria, expose patients to adverse drug events, and increase costs. Perhaps unique among upper respiratory tract infections, clinicians have good, objective criteria in the form of GABHS testing to guide the antibiotic treatment of children with sore throat. Limiting antibiotic prescribing to children with a positive GABHS test result is a feasible goal for primary care physicians and an important step toward judicious use of antibiotics overall," the authors write.

To learn more about proper use of antibiotics, click here.

Editor's Note: This study was supported by the Agency for Healthcare Research and Quality through a Career Development Award to Dr. Linder. Co-author Grace M. Lee, M.D., M.P.H., is supported by an Agency for Healthcare Research and Quality Career Development Award.

Friday, December 16, 2005

Probiotics

TRADE NAMES

Mega Dophilus (Natren), Healthy Trinity (Natren), Bifido Factor (Natren), Digesta Lac (Natren), Life Start (Natren), Probiata (Wakunaga Consumer).

DESCRIPTION

Probiotics are defined as live microorganisms, including Lactobacillus species, Bifidobacterium species and yeasts, that may beneficially affect the host upon ingestion by improving the balance of the intestinal microflora. The dietary use of live microorganisms has a long history. Mention of cultured dairy products is found in the Bible and the sacred books of Hinduism. Soured milks and cultured dairy products, such as kefir, koumiss, leben and dahi, were often used therapeutically before the existence of microorganisms was recognized. The use of microorganisms in food fermentation is one of the oldest methods for producing and preserving food. Much of the world depends upon various fermented foods that are staples in the diet.

Élie Metchnikoff, the father of modern immunology, spoke highly about the possible health benefits of the lactic acid-bacteria (LAB) Lactobacillus bulgaricus and Streptococcus thermophilus in his writings at the turn of the last century. He wrote in his book, The Prolongation of Life, that consumption of live bacteria, such as Lactobacillus bulgaricus and Streptococcus thermophilus, in the form of yogurt was beneficial for gastrointestinal health, as well as for health in general, and for longevity. Some recent research suggests that certain live microorganisms may have immunomodulatory and anticarcinogenic effects, as well as other health benefits. There is presently much active research focusing on the development of target-specific probiotics containing well-characterized bacteria that are selected for their health-enhancing characteristics. These new probiotics are entering the marketplace in the form of nutritional supplements and functional foods, such as yogurt functional food products.

The gastrointestinal tract represents a complex ecosystem in which a delicate balance exists between the intestinal microflora and the host. The microflora are principally comprised of facultative anaerobes and obligate anaerobes. Approximately 95% of the intestinal bacterial population in humans is comprised of obligate anaerobes, including Bifidobacterium, Clostridium, Eubacterium, Fusobacterium, Peptococcus, Peptostreptococcus and Bacteroides. Approximately 1% to 10% of the intestinal population is comprised of facultative anaerobes, including Lactobacillus, Escherichia coli, Klebsiella, Streptococcus, Staphylococcus and Bacillus. Aerobic organisms are not present in the intestinal tract of healthy individuals with the exception of Pseudomonas, which is present in very small amounts. Most of the bacteria are present in the colon where the bacterial concentration ranges between 1011 to 1012 colony-forming units (CPU) per milliliter.

The intestinal microflora are important for maturation of the immune system, the development of normal intestinal morphology and in order to maintain a chronic and immunologically balanced inflammatory response. The microflora reinforce the barrier function of the intestinal mucosa, helping in the prevention of the attachment of pathogenic microorganisms and the entry of allergens. Some members of the microflora may contribute to the body's requirements for certain vitamins, including biotin, pantothenic acid and vitamin B12. Alteration of the microbial flora of the intestine, such as may occur with antibiotic use, disease and aging, can negatively affect its beneficial role.

The probiotics that are marketed as nutritional supplements and in functional foods, such as yogurts, are principally the Bifidobacterium species and the Lactobacillus species. Probiotics are sometimes called colonic foods. Most of the presently available probiotics are bacteria. Saccharomyces boulardii is an example of a probiotic yeast.

The following describe the various bacteria and yeasts used as probiotics:

BIFIDOBACTERIUM

Bifidobacteria are normal inhabitants of the human and animal colon. Newborns, especially those that are breast-fed, are colonized with bifidobacteria within days after birth. Bifidobacteria were first isolated from the feces of breast-fed infants. The population of these bacteria in the colon appears to be relatively stable until advanced age when it appears to decline. The bifidobacteria population is influenced by a number of factors, including diet, antibiotics and stress. Bifidobacteria are gram-positive anaerobes. They are non-motile, non-spore forming and catalase-negative. They have various shapes, including short, curved rods, club-shaped rods and bifurcated Y-shaped rods. Their name is derived from the observation that they often exist in a Y-shaped or bifid form. The guanine and cytosine content of their DNA is between 54 mol% and 67mol%. They are saccharolytic organisms that produce acetic and lactic acids without generation of CO2, except during degradation of gluconate. They are also classified as lactic acid bacteria (LAB). To date, 30 species of bifidobacteria have been isolated. Bifidobacteria used as probiotics include Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium animalis, Bifidobacterium thermophilum, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis and Bifidobacterium lactis. Specific strains of bifidobacteria used as probiotics include Bifidobacterium breve strain Yakult, Bifidobacterium breve RO7O, Bifidobacterium lactis Bb12, Bifidobacterium longum RO23, Bifidobacterium bifidum RO71, Bifidobacterium infantis RO33, Bifidobacterium longum BB536 and Bifidobacterium longum SBT-2928.

LACTOBACILLUS

Lactobacilli are normal inhabitants of the human intestine and vagina. Lactobacilli are gram-positive facultative anaerobes. They are non-spore forming and non-flagellated rod or coccobacilli. The guanine and cytosine content of their DNA is between 32 mol% and 51 mol%. They are either aerotolerant or anaerobic and strictly fermentative. In the homofermentative case, glucose is fermented predominantly to lactic acid. Lactobacilli are also classified as lactic acid bacteria (LAB). To date, 56 species of the genus Lactobacillus have been identified. Lactobacilli used as probiotics include Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus cellobiosus, Lactobacillus crispatus, Lactobacillus curvatus, Lactobacillus fermentum, Lactobacillus GG (Lactobacillus rhamnosus or Lactobacillus casei subspecies rhamnosus), Lactobacillus gasseri, Lactobacillus johnsonii, Lactobacillus plantarum and Lactobacillus salivarus. Lactobacillus plantarum 299v strain originates from sour dough. Lactobacillus plantarum itself is of human origin. Other probiotic strains of Lactobacillus are Lactobacillus acidophilus BG2FO4, Lactobacillus acidophilus INT-9, Lactobacillus plantarum ST31, Lactobacillus reuteri, Lactobacillus johnsonii LA1, Lactobacillus acidophilus NCFB 1748, Lactobacillus casei Shirota, Lactobacillus acidophilus NCFM, Lactobacillus acidophilus DDS-1, Lactobacillus delbrueckii subspecies delbrueckii, Lactobacillus delbrueckii subspecies bulgaricus type 2038, Lactobacillus acidophilus SBT-2062, Lactobacillus brevis, Lactobacillus salivarius UCC 118 and Lactobacillus paracasei subsp paracasei F19.

LACTOCOCCUS

Lactococci are gram-positive facultative anaerobes. They are also classified as lactic acid bacteria (LAB). Lactococcus lactis (formerly known as Streptococcus lactis) is found in dairy products and is commonly responsible for the souring of milk. Lactococci that are used or are being developed as probiotics include Lactococcus lactis, Lactococcus lactis subspecies cremoris (Streptococcus cremoris), Lactococcus lactis subspecies lactis NCDO 712, Lactococcus lactis subspecies lactis NIAI 527, Lactococcus lactis subspecies lactis NIAI 1061, Lactococcus lactis subspecies lactis biovar diacetylactis NIAI 8 W and Lactococcus lactis subspecies lactis biovar diacetylactis ATCC 13675.

SACCHAROMYCES

Saccharomyces belongs to the yeast family. The principal probiotic yeast is Saccharomyces boulardii. Saccharomyces boulardii is also known as Saccharomyces cerevisiae Hansen CBS 5296 and S. boulardii. S. boulardii is normally a nonpathogenic yeast. S. boulardii has been used to treat diarrhea associated with antibiotic use.

STREPTOCOCCUS THERMOPHILUS

Streptococcus thermophilus is a gram-positive facultative anaerobe. It is a cytochrome-, oxidase- and catalase-negative organism that is nonmotile, non-spore forming and homofermentative. Streptococcus thermophilus is an alpha-hemolytic species of the viridans group. It is also classified as a lactic acid bacteria (LAB). Steptococcus thermophilus is found in milk and milk products. It is a probiotic and used in the production of yogurt. Streptococcus salivarus subspecies thermophilus type 1131 is another probiotic strain.

ENTEROCOCCUS

Enterococci are gram-positive, facultative anaerobic cocci of the Streptococcaceae family. They are spherical to ovoid and occur in pairs or short chains. Enterococci are catalase-negative, non-spore forming and usually nonmotile. Enterococci are part of the intestinal microflora of humans and animals. Enterococcus faecium SF68 is a probiotic strain that has been used in the management of diarrheal illnesses.

ACTIONS AND PHARMACOLOGY

ACTIONS

Probiotics may have antimicrobial, immunomodulatory, anticarcinogenic, antidiarrheal, antiallergenic and antioxidant activities.

MECHANISM OF ACTION

Lactobacillus plantarum 299v, which is derived from sour dough and which is used to ferment sauerkraut and salami, has been demonstrated to improve the recovery of patients with enteric bacterial infections. This bacterium adheres to reinforce the barrier function of the intestinal mucosa, thus preventing the attachment of the pathogenic bacteria to the intestinal wall. Bifidobacterium breve was found to eradicate Campylobacter jejuni from the stools of children with enteritis, although less rapidly than in those treated with erythromycin. Lactobacillus GG was found to eradicate Clostridium difficile in patients with relapsing colitis, and supplementation of infant formula milk with Bifidobacterium bifidum and Streptococcus thermophilus reduced rotavirus shedding and episodes of diarrhea in hospitalized children.

The antimicrobial activity of probiotics is thought to be accounted for, in large part, by their ability to colonize the colon and reinforce the barrier function of the intestinal mucosa. Probiotics, such as Lactobacillus bulgaricus, which do not adhere as well to the intestinal mucosa, are much less effective against enteric pathogens. In addition, some probiotics have been found to secrete antimicrobial substances. These substances are known as bacteriocins. Such a bacteriocin has been isolated from Lactobacillus plantarum ST31, a probiotic derived from sour dough. The substance was found to be a 20 amino acid peptide. A different bacteriocin was isolated from another strain of Lactobacillus plantarum. The bacteriocin has 27 amino acids and contains lanthionine residues. This type of bacteriocin is classified as a lantibiotic.

Lactobacillus casei has been demonstrated to increase levels of circulating immunoglobulin A (IgA) in infants infected with rotavirus. This has been found to be correlated with shortened duration of rotavirus-induced diarrhea.

Lactobacillus GG has also been shown to potentiate intestinal immune response to rotavirus infection in children. Lactobacillus acidophilus and Bifidobacterium bifidum appear to enhance the nonspecific immune phagocytic activity of circulating blood granulocytes. This effect may account, in part, for the stimulation of IgA responses in infants infected with rotavirus. In healthy individuals, Lactobacillus salivarius UCC118 and Lactobacillus johnsonii LA1 were demonstrated to produce an increase in the phagocytic activity of peripheral blood monocytes and granulocytes. Also, Lactobacillus johnsonii LA1, but not Lactobacillus salivarius UCC118, was found to increase the frequency of interferon-gamma-producing peripheral blood monocytes.

Lactobacillus GG has been shown to inhibit chemically induced intestinal tumors in rats. The probiotic appears to alter the initiation and/or promotional events of the chemically-induced tumors. Lactobacillus GG also binds to some chemical carcinogens.

Saccharomyces boulardii has been shown to prevent antibiotic-associated diarrhea and also to prevent diarrhea in critically ill tube-fed patients. The mechanism of this antidiarrheal effect is not well understood. S. boulardii has been found to secrete a protease which digests two protein exotoxins, toxin A and toxin B, which appear to mediate diarrhea and colitis caused by Clostridium difficile. The protective effects of S. boulardii on C. difficile-induced inflammatory diarrhea may, in part, be due to proteolytic digestion of toxin A and toxin B by a secreted protease.

Dietary antigens may induce an immunoinflammatory response that impairs the barrier function of the intestine, resulting in aberrant absorption of intralumenal antigens. This may account, in part, for food allergies. Probiotics that colonize the colon may be helpful in the management of some with food allergies by reinforcing the barrier function of the intestinal mucosa.

Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12 were found to produce significant improvement of atopic eczema in children with food allergies. The decrease in the signs and symptoms of atopic eczema occurred in parallel with a reduction in the concentration of circulating CD4+ T lymphocytes and an increase in transforming growth factor beta1 (TGF-beta1), indicating suppressive effects on T cell functions in this disorder. These probiotics may help restore the Th1/Th2 balance in atopic eczema.

Lactobacillus GG was found to scavenge superoxide anion radicals, inhibit lipid peroxidation and chelate iron in vitro. The iron chelating active of Lactobacillus GG may account, in part, for its antioxidant activity. Other lactic acid bacteria, including strains of Lactobacillus acidophilus, Lactobacillus bulgaricus, Bifidobaterium longum and Streptococcus thermophilus, have also demonstrated antioxidative ability. Mechanisms include chelation of metal ions (iron, copper), scavenging of reactive oxygen species and reducing activity.

PHARMACOKINETICS

The effectiveness of probiotics is related to their ability to survive in the acidic stomach environment and the alkaline conditions in the duodenum, as well as their ability to adhere to the intestinal mucosa of the colon and to colonize the colon. Some probiotics, such as Lactobacillus GG and Lactobacillus plantarum 299v, are better able to colonize the colon than others. After passage through the stomach and the small intestine, those probiotics that do survive become established transiently in the colon.

INDICATIONS AND USAGE

Probiotics have been used with some benefit in the prevention and treatment of some gastrointestinal disorders, including antibiotic-associated diarrhea and some infectious and viral diarrheas, most notably rotavirus-induced diarrhea in infants and children, lactose intolerance, sucrase and maltase deficiencies and inflammatory bowel disease. Probiotics may be of benefit in some with food allergies, but supporting evidence is preliminary. They may favorably modulate immunity in some circumstances and may have anticarcinogenic effects. There is the suggestion in some preliminary research that they may have some hypocholesterolemic activity.

There is some evidence to support the use of probiotics to re-colonize the vaginas of women with recurrent vaginosis.

RESEARCH SUMMARY

Among the probiotics, only S. boulardii, E. faecium and Lactobacillus sp. have been useful in preventing antibiotic-related diarrhea. In one double-blind study, 180 hospitalized patients on antibiotic therapy were randomized to receive placebo or S. boulardii supplementation. Incidence of diarrhea was significantly lower among those receiving the probiotic, compared with controls (9% and 22%, respectively). These results have been confirmed in other controlled studies.

Lactobacillus GG significantly reduced the severity and duration of rotavirus diarrhea in infants in a double-blind, placebo-controlled study. Other researchers have demonstrated that the incidence of acute diarrhea and rotavirus shedding can be significantly reduced among infants admitted to the hospital by adding Bifidobacterium bifidum and Streptococcus thermophilus to infant formula. Lactobacillus GG has been shown helpful in the treatment of diarrhea associated with relapsing colitis due to Clostridium difficile. These studies, however, were small and uncontrolled. In a double-blind, placebo-controlled trial, Saccharomyces boulardii was significantly superior to placebo in treating diarrhea despite having no apparent effect on Clostridium difficile toxin. The use of probiotics in the attempted prevention and treatment of traveler's diarrhea, most commonly caused by enterotoxigenic E. coli, has produced inconclusive results. More study is needed.

Reduced fecal concentrations of various probiotics have been noted, although without conclusive power, in some with active ulcerative colitis, Crohn's disease, active pouchitis and some other inflammatory gastrointestinal conditions. Lactobacillus species prevented development of spontaneous colitis in interleukin 10-deficient mice. Lactobacillus plantarum ameliorated colitis that was already established in the same animal model.

In a clinical trial, subjects with chronic relapsing pouchitis given a probiotic preparation for nine months, consisting of L. casei, L. plantarum, L. acidophilus and L. delbruekii subspecies bulgaricus, had significantly fewer relapses than did unsupplemented subjects receiving placebo. No side effects were seen. Some researchers believe that Lactobacillus GG may also be useful in treating pouchitis.

Some lactic acid bacteria, including L. plantarum, L. rhamnosus, L. casei and Lactobacillus bulgaricus, have demonstrated immuno-regulatory effects that might help protect against some allergic disorders. There is some evidence that some of these probiotic strains can reduce the intestinal inflammation associated with some food allergies, including cow's milk allergy among neonates. Breast-fed infants of nursing mothers given Lactobacillus GG had significantly improved atopic dermatitis, compared with infants not exposed to this probiotic.

There are in vitro, animal and some preliminary human data suggesting that some probiotics can bind and inactivate some carcinogens, can directly inhibit the growth of some tumors and can inhibit bacteria that may convert precarcinogens into carcinogens. L. acidophilus and L. casei have exhibited the latter activity in human volunteers. There is some preliminary evidence that L. casei may have reduced the recurrence of bladder tumors in humans. Confirmatory trials are needed. Animal work has suggested that some lactic-acid bacteria might help protect against colon cancer. Again, more research is needed.

Dairy products containing L. acidophilus have been credited with lowering cholesterol levels in some animal experiments. It has been hypothesized that bacterial assimilation of cholesterol in the intestine might reduce cholesterol stores available for absorption into the blood. To date, there is no credible evidence showing that any of the probiotics can lower cholesterol levels in humans. More study may be warranted. Yogurt has been used for some time as an "alternative" treatment for vaginitis. In an early test of this hypothesis, women with recurrent candidal vaginitis were treated with yogurt for six months. This was a crossover trial with subjects serving as their own controls. Daily ingestion of 8 ounces of yogurt significantly decreased both candidal colonization and infection.

Recently L. acidophilus, L. crispatus and L. delbrueckii subspecies delbrueckii all inhibited bacterial vaginosis-associated bacterial species in vitro. The researchers concluded that these probiotics might be useful for vaginal recolonization in women with recurrent vaginosis.

Owing to the fact that yogurt and some other probiotic-containing products are foods, rather than regulated pharmaceuticals, and owing to the fact that the probiotic content and potential of these food products may be highly variable, some researchers and clinicians have questioned the use of these products to treat vaginitis. In any event, larger better controlled studies are needed to further evaluate their reliability and efficacy in this context.

CONTRAINDICATIONS, PRECAUTIONS, ADVERSE REACTIONS

CONTRAINDICATIONS

Probiotics are contraindicated in those hypersensitive to any component of a probiotic-containing product.

PRECAUTIONS

Pregnant women and nursing mothers should only use probiotic nutritional supplements if recommended by their physicians.

The use of probiotics for the treatment of any disorder must be medically supervised.

ADVERSE REACTIONS

The most common adverse reactions with use of probiotics are gastrointestinal and include flatulence and constipation. Probiotics are generally well tolerated.

Four cases of Saccharomyces boulardii fungemia have been reported. All of the patients had indwelling catheters, and the fungemia was thought to be due to catheter contamination.

There are a few reports of Lactobacillus bacteremia and endocarditis. In all cases, there were underlying conditions, including cancer, diabetes mellitus and recent surgery.

There is one death reported secondary to Lactobacillus bacteremia.

There is one report of meningitis caused by Bifidobacterium in an infant.

INTERACTIONS

NUTRITIONAL SUPPLEMENTS

Prebiotics: Concomitant use of prebiotics and probiotics may enhance the effectiveness of the probiotics. See Prebiotics. See Symbiotics.

DOSAGE AND ADMINISTRATION

There are many probiotic products available. These products contain various Lactobacillus strains, various Bifidobacterium strains, combinations of lactobacilli and bifidobacteria and combinations of probiotics and prebiotics. Typical doses of probiotics range from one to ten billion colony-forming units (CFU) a few times a week. Probiotics need to be consumed at least a few times a week to maintain their effect on the intestinal microecology.

The development of probiotic-containing yogurt products is actively being pursued by major food companies. These yogurt products are functional yogurt food products.

LITERATURE

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Arunachalam KD. Role of bifidobacteria in nutrition, medicine and technology. Nutr Res. 1999; 19:1559-1597.
Bielecka M, Biedrzycka E, Biedrzycka E, et al. Interaction of Bifidobacterium and Salmonella during associated growth. Int J Food Microbiol. 1998; 45:151-155.
Bleichner G, Blehaut H, Mentec H, Moyse D. Saccharomyces boulardii prevents diarrhea in critically ill tube-fed patients. A multicenter, randomized, double-blind, placebo-controlled trial. Intensive Care Med. 1997; 23:517-523.
Blum S, Reniero R, Schiffrin EJ, et al. Adhesion studies for probiotics: need for validation and refinement. Trends Food Sci Technol. 1999; 10:405-410.
Castagliuolo I, Riegler MF, Valenick L, et al. Saccharomyces boulardii protease inhibits the effects of Clostridium difficile toxins A and B in human colonic mucosa. Infect Immun. 1999; 67:302-307.
Czerucka D, Rampal P. Effect of Saccharomyces boulardii on cAMP- and Ca22-dependent C1- secretion in T84 cells. Dig Dis Sci. 1999; 44:2359-2368.
Dugas B, Mercenier A, Lenoir-Wijnkoop I, et al. Immunity and probiotics. Immunol Today. 1999; 20:387-390.
Elmer GW, McFarland LV, Surawicz CM, et al. Behavior of Saccharomyces boulardii in recurrent Clostridium difficile disease patients. Aliment Pharmacol Ther. 1999; 13:1663-1668.
Fredenucci I, Chomarat M, Boucaud C, Flandrois JP. Saccharomyces boulardii fungemia in a patient receiving Ultra-levure therapy. Clin Infect Dis. 1998; 27:222-223.
Gionchetti P, Rizzello F, Venturi A, Campieri M. Probiotics in infective diarrhoea and inflammatory bowel diseases. J Gastroenterol Hepatol. 2000; 15:489-493.
Gomes AMP, Malcata FX. Bifidobacterium spp. and Lactobacillus acidophilus: biological, biochemical, technological and therapeutical properties relevant for use as probiotics. Trends Food Sci Technol. 1999; 10:139-157.
Herias MV, Hessle C, Telemo E, et al. Immunomodulatory effects of Lactobacillus plantarum colonizing the intestine of gnotobiotic rats. Clin Exp Immunol. 1999; 116:283-290.
Hilton E, Isenberg HD, Alperstein P, et al. Ingestion of yogurt containing Lactobacillus acidophilus. Ann Int Med. 1992; 116:353-357.
Jahn HU, Ullrich R, Schneider T, et al. Immunological and trophical effects of Saccharomyces boulardii on the small intestine in healthy human volunteers. Digestion. 1996; 57:95-104.
Kimoto H, Kurisaki MN, Tsuji, et al. Lactococci as probiotic strains: adhesion to human enterocyte-like Caco-2 cells and tolerance to low pH and bile. Lett Applied Microbiol. 1999; 29:313-316.
Kirjavainen PV, Ouwehand AC, Isolauri E, Salminen SJ. The ability of probiotic bacteria to bind to human intestinal mucus. FEMS Microbiol Lett. 1998; 167:185-189.
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Mack DR, Michail S, Wei S, et al. Probiotics inhibit enteropathogenic E. coli adherence in vitro by inducing intestinal mucin gene expression. Am J. Physiol. 1999; 276(4 Pt 1):G941-G950.
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Mattila-Sandholm T. The PROBDEMO project: demonstration of the nutritional functionality of probiotic foods. Trends Food Sci Technol. 1999; 10:385-386.
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Priobiotics

Penicillin Allergy

Penicillin allergy: The most common drug allergy

Penicillin allergy is the most common drug allergy, and if you're allergic to it your reactions can range from annoying to life-threatening. Find out what you can do to avoid potentially dangerous reactions.

Chances are your doctor has at one time or another considered writing you a prescription for amoxicillin. It's one of the most frequently prescribed medications, and it's commonly used to treat strep throat and ear infections.

But if you have an allergy to penicillin, taking common drugs such as amoxicillin and other medicines in the penicillin family can be dangerous. Allergic responses to penicillin range from annoying rashes to life-threatening reactions, such as difficulty breathing.

Penicillin allergy is the most common drug allergy. Knowing the signs of an allergic reaction can help you spot a serious penicillin allergy before it's too late.

About penicillin

Penicillin belongs to a family of drugs called beta-lactam antibiotics. These drugs include penicillin and amoxicillin, which are relatively inexpensive and generally effective at eradicating many common bacterial infections. These include skin, ear, sinus and upper respiratory infections.

Taken orally or injected, penicillin works by stopping the growth of bacteria in your body. Several different varieties of penicillin exist, and each targets a different infection in a different part of your body. You may have heard of some of the other varieties of penicillin, including:


Amoxicillin
Ampicillin
Dicloxacillin
Nafcillin
Penicillin V
Penicillin G


Allergic reaction to penicillin

You aren't born allergic to penicillin, but you can develop an allergy to the drug once you've been exposed to it. After that, re-exposure to penicillin or related antibiotics can trigger an allergic reaction.

Allergic reactions occur because your immune system responds to the drug as if it were a harmful substance instead of a helpful remedy. For reasons not fully understood, your body creates antibodies called immunoglobulin to attack the medication. In most cases of penicillin allergy, the type of immunoglobulin that causes the most problems is type E (IgE).

The most common allergic reactions to penicillin are rashes, which aren't life-threatening. Other common reactions include:

Hives
Itchy eyes
Swollen lips, tongue or face (angioedema)


Tell your doctor if you notice any of these or other reactions. He or she can determine whether these are signs of allergic reaction and may prescribe an alternative medication.
In rare instances your allergy can cause an anaphylactic (an-uh-fuh-LAK-tik) reaction, which can be deadly. This type of reaction usually develops within an hour of taking penicillin, and the reaction involves your entire body. In an anaphylactic reaction your airway tubes (bronchi) may constrict, making it hard to breathe, and your blood pressure may drop to life-threatening levels, making you feel dizzy or causing you to lose consciousness. You might also notice:


Wheezing
Dizziness
Loss of consciousness
Rapid or weak pulse
Bluing of your skin, including your lips and nail beds
Diarrhea
Nausea and vomiting
Seek medical attention immediately if you think you're having an anaphylactic reaction.


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Hives and angioedema
Anaphylaxis
Anaphylaxis: First aid

Diagnosing an allergy

Your doctor might recommend an allergy skin test if you need to know whether you're allergic to penicillin — such as when you have an infection that's best treated with penicillin. The test involves injecting a tiny amount of penicillin into your skin and watching that part of your body for signs of inflammation. If the skin test is positive, you're at increased risk of a reaction if you take penicillin or closely related antibiotics.

MORE ON THIS TOPIC

Allergy skin tests: Identify the sources of your sneezing

Living with penicillin allergy

The best way to avoid an allergic reaction to penicillin is to avoid penicillin and similar antibiotics altogether, if possible. If you're allergic to penicillin, it doesn't mean you're necessarily allergic to all antibiotics. Your doctor may be able to give you an antibiotic that's distantly related to penicillin without causing any problems. Antibiotics completely unrelated to penicillin also are available.

For some infections it may be absolutely necessary for you to take penicillin. If this is the case, your doctor may recommend desensitization. During the desensitization process, you receive small but gradually increasing doses of penicillin orally or intravenously. Because desensitization can trigger an allergic reaction, it's only attempted in a controlled hospital setting — and only when penicillin is absolutely necessary. Your desensitization only lasts as long as you continue taking penicillin. If you stop and then need to take penicillin again later, you'll need to go through the desensitization process again.

Penicillin in pregnancy

Some pregnant women receive penicillin to prevent them from passing group B streptococci (GBS) to their babies — it's generally a safe option for developing babies and it rarely causes fatal infections in newborns. Doctors recommend that all pregnant women be tested for GBS — as many as 30 percent of all women carry the organism. If you're a carrier, your doctor can help you reduce the risk of transmitting the disease to your baby by giving you an antibiotic. Penicillin is the first choice, but if you're allergic, alternative medications are available. Always tell your doctor if you think you're allergic to penicillin.

Talk to your doctor

If you think you've had reactions to penicillin in the past, be sure to tell your doctor or other medical professional. Let your doctor know about any new reactions you notice when taking your medication. If your doctor determines that you're allergic to penicillin, it's a good idea to wear a medical alert bracelet that describes your allergy, or you might want to carry an alert card in your wallet or purse.

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Drug allergy and other drug reactions: Are you at risk?

Mayo Clinic

Monday, December 12, 2005

Avelox

Avelox - moxifloxacin(moxie FLOCKS ah sin)Avelox, Avelox I.V.

What is the most important information I should know about Avelox?

Take all of the Avelox that has been prescribed for you even if you begin to feel better. Your symptoms may start to improve before the infection is completely treated.


Do not take Avelox without first talking to your doctor if you or any member of your family have a heart condition known as prolongation of the QT interval. Also, do not take Avelox if you are being treated for heart rhythm disturbances with drugs such as quinidine (Cardioquin, Quinidex, Quinaglute, others), procainamide (Pronestyl, Procan SR, others), amiodarone (Cordarone, Pacerone, others), sotalol (Betapace), and others.

Take Avelox at least 4 hours before or 8 hours after antacids that contain magnesium, calcium, or aluminum (e.g., Tums, Rolaids, Maalox, others); the ulcer medicine sucralfate (Carafate); vitamin or mineral supplements that contain iron or zinc; or didanosine chewable/buffered tablets or pediatric powder for oral solution (ddI,
Videx, Videx Pediatric, others). These medicines may decrease the effectiveness of Avelox.

Use caution when driving, operating machinery, or performing other hazardous activities. Avelox may cause
dizziness. If you experience dizziness, avoid these activities.

What is Avelox?

Avelox is an antibiotic in the class of drugs called fluoroquinolones. It fights bacteria in the body.

Avelox is used to treat
bacterial infections including pneumonia, sinusitis, and worsening of chronic bronchitis.

Avelox may also be used for purposes other than those listed in this medication guide.


What should I discuss with my healthcare provider before taking Avelox?

Do not take Avelox without first talking to your doctor if you or any member of your family have a heart condition known as prolongation of the QT interval. Also, do not take Avelox if you are being treated for heart rhythm disturbances with drugs such as quinidine (Cardioquin, Quinidex, Quinaglute, others), procainamide (Pronestyl, Procan SR, others), amiodarone (Cordarone, Pacerone, others), sotalol (Betapace), and others.

Before taking Avelox, tell your doctor if you have

a low level of potassium in your blood;

a slow heart rate;

heart disease;

liver disease; or

epilepsy or another seizure disorder.

You may not be able to take Avelox or you may require a dosage adjustment or special monitoring during your treatment.

Avelox is in the FDA pregnancy category C. This means that it is not known whether Avelox will be harmful to an unborn baby. Do not take Avelox without first talking to your doctor if you are pregnant or could become pregnant during treatment.

It is unknown whether Avelox passes into breast milk. Do not take Avelox without first talking to your doctor if you are breast feeding a baby.

Avelox is not approved for use by children younger than 18 years old.


How should I take Avelox?

Take Avelox exactly as directed by your doctor. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each oral dose with a full glass (8 ounces) of water. Drink plenty of fluid while taking Avelox.

Avelox can be taken with or without food.

Avelox is usually taken once a day. Take each dose at the same time every day. Follow your doctor's instructions.

Avelox may also be given by a healthcare provider by intravenous (IV) infusion.

Take all of the Avelox that has been prescribed for you even if you begin to feel better. Your symptoms may start to improve before the infection is completely treated.

Take Avelox at least 4 hours before or 8 hours after antacids that contain magnesium, calcium, or aluminum (e.g., Tums, Rolaids, Maalox, others); the ulcer medicine sucralfate (Carafate); vitamin or mineral supplements that contain iron or zinc; or didanosine chewable/buffered tablets or pediatric powder for oral solution (ddI, Videx, Videx Pediatric, others). These medicines may decrease the effectiveness of Avelox.

Store this medication at room temperature away from moisture and heat.


What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication.


What happens if I overdose?

Seek emergency medical attention.

Symptoms of a Avelox overdose include seizures, poor coordination, tremors, sleepiness, vomiting and diarrhea.


What should I avoid while taking Avelox?

Avoid prolonged exposure to sunlight. Although it has not been reported with the use of Avelox, other similar medicines have caused increased sensitivity of the skin to sunlight. Severe sunburn has resulted, even with minimal sun exposure. If exposure to the sun is unavoidable while taking Avelox, wear protective clothing and use sunscreen. Call your doctor if you experience severe burning, redness, itching, rash, or swelling after exposure to the sun.

Use caution when driving, operating machinery, or performing other hazardous activities. Avelox may cause dizziness. If you experience dizziness, avoid these activitie


What are the possible side effects of Avelox?

If you experience any of the following serious side effects, stop taking Avelox and seek emergency medical attention or contact your doctor immediately:

an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);

irregular or rapid heartbeats;

fainting;

seizures;

liver damage (yellowing of the skin or eyes, nausea, abdominal pain or discomfort, unusual bleeding or bruising, severe fatigue);

muscle or joint pain; or

skin rash.

If you experience any of the following less serious side effects, continue taking Avelox and talk to your doctor:

nausea, vomiting, abdominal pain, or diarrhea;

dizziness;

headache; or

increased sensitivity of the skin to sunlight.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.


What other drugs will affect Avelox?

Take Avelox at least 4 hours before or 8 hours after antacids that contain magnesium, calcium, or aluminum (e.g., Tums, Rolaids, Maalox, others); the ulcer medicine sucralfate (Carafate); vitamin or mineral supplements that contain iron or zinc; or didanosine chewable/buffered tablets or pediatric powder for oral solution (ddI, Videx, Videx Pediatric, others). These medicines may decrease the effectiveness of Avelox.

Do not take Avelox without first talking to your doctor if you are taking any of the following drugs:

the heart medicines quinidine (Cardioquin, Quinidex, Quinaglute, others), procainamide (Pronestyl, Procan SR, others), amiodarone (Cordarone, Pacerone, others), sotalol (Betapace), and others;

a tricyclic antidepressant including amitriptyline (Elavil, Endep), amoxapine (Asendin), imipramine (Tofranil), nortriptyline (Pamelor), doxepin (Sinequan), and others;

a phenothiazine including chlorpromazine (Thorazine), fluphenazine (Prolixin), perphenazine (Trilafon), mesoridazine (Serentil), thioridazine (Mellaril), and others;

erythromycin (E-Mycin, Ery-Tab, E.E.S., others); or

cisapride (Propulsid).

Avelox and the drugs listed above may affect the rhythm of your heartbeats. You may not be able to take Avelox, or you may require a dosage adjustment or special monitoring during treatment if you are taking any of the medicines listed above.

Before taking Avelox, tell your doctor if you are taking:

warfarin (Coumadin); or

a nonsteroidal anti-inflammatory drug (NSAID) such as ibuprofen (Motrin, Advil, Nuprin, others), naproxen (Aleve, Naprosyn, Anaprox), ketoprofen (Orudis KT, Orudis, Oruvail), and others.

You may not be able to take Avelox, or you may require a dosage adjustment or special monitoring during treatment if you are taking any of the medicines listed above.

Drugs other than those listed here may also interact with Avelox. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including herbal products.


Where can I get more information?

Your pharmacist has additional information about Avelox written for health professionals that you may read.


Avelox