Sunday, November 27, 2005

What are Antibiotics?


Because of our constant battles with infections, I thought it might be interesting to know more about antibiotics. What they are, how they work, what they do and why we should be careful in taking them so as to not build up an immunity to them


Antibiotics -


In common usage, an antibiotic is a drug that kills certain kinds of bacteria, but which is generally harmless to the host and is used to treat infection. The term was originally used to describe only antibacterial formulations derived from living organisms but is now used in reference to synthetic antimicrobials such as the Sulfonamides.In general, the term can also apply to substances that affect prions, viruses, fungi, worms or any other intracellular or extracellular parasite, but the antibacterial kind are the most common. Generally, the antibiotics are not effective in viral infections.



Antibiotics are meant to fight off bacterial infections such as pneumonia (e.g. legionnaires' disease), meningitis, cystitis, ear infections, abscess, Lyme disease (tick-transmitted), leprosy & tuberculosis. They cannot be used against viral infections..

The first antibiotic discovered by Alexander Fleming, a Scottish scientist in 1928 is penicillin. It was only in 1941 that penicillin made it's public debut..

Antibiotic drugs are grouped into families such as cephalosporins, fluoroquinolones, penicillins, erythromycins, polypeptides, tetracyclines, aminoglycosides, quinolones, streptogramins & sulfonamides. Each family comprises of many members..

Antibiotics are classified as narrow-spectrum drugs when they are effective against a few types of bacteria & broad-spectrum drugs when they are effective against a wider range of bacteria..

Combination of antibiotics are sometimes used to treat certain infections like leprosy & tuberculosis.. T

hey are sometimes prescribed to treat conditions such as acne, food poisoning, gout & nosebleed..

Preventive antibiotic therapy is meant to prevent bacterial infection, e.g. to reduce the risk of endocarditis (inflammation of the lining inside the heart chambers & heart valves) or to reduce the risk of contracting traveler's diarrhea or to protect people who have a weak immune system because of AIDS or undergoing chemotherapy treatment for cancer..

Different antibiotics kill different bacteria differently..

Though antibiotics can kill off sensitive bacteria, the resistant ones survive & even prosper (i.e. grow & multiply)..

Animals like chickens, pigs, turkeys, cattle also receive their dose of antibiotics in order to either promote growth or to treat & prevent diseases. Fruits & vegetables are also not spared as antibiotics are sprayed to prevent bacterial infections.

Antibiotic resistance.

Antibiotic resistance (AR) is the result of an overuse or misuse of antibiotics. This resistance is certainly a big worry..

Did you know there are certain strains of bacteria that have become impossible to eliminate with almost all types of antibiotics?.

Broad-spectrum antibiotics are the ones that can promote AR as well as interfere with the absorption of vitamins B6 & B12, folic acid, minerals like magnesium, calcium & potassium.

Side effects.

Allergies may develop with the use of antibiotics, frequently with penicillin..

Side effects from antibiotics can include diarrhea, lightheadness, headaches, cramp, vomiting & stomach discomfort. Consult your physician if these side effects persist or become serious..

Taking the antibiotic erythromycin (primarily used to treat bacteria infections e.g. bronchitis, Legionnaires' disease, pneumonia, rheumatic fever & venereal disease) with Liptor, a statin drug shown to lower cholesterol can cause muscle damage.

Check with your physician before combining these 2 drugs or learn how to lower cholesterol without drugs here..

Antibiotics can destroy the beneficial flora (needed for digestion & protection against infection) in the gut..

Antibiotic therapy can weaken the immune system, simply because it suppresses the body's natural defense system against illness.

Prolong use

. A deficiency in vitamin K can occur..

.A reduction of the manufacture of biotin in the intestines.. Cause people to be light-sensitive

. Examples of such antibiotics : doxycycline, ciproflaxacin & ofloxacin

.Consuming antibiotics

If you must consume antibiotics :

. Complete the full course even if symptoms improve, otherwise, the antibiotics are not given enough time to work on the infection completely, which can cause a relapse. What's more, the bacteria can become so resistant that the antibiotics no longer work for you the next time..

Follow all the instructions carefully.

Take the correct dosages on time..

Do not take a double dose to make up for a missed one.

Either resume to take the forgotten dose at once or if it's time for the next dose, just continue with it & skip the earlier missed dose..

Do not share antibiotics with anyone..

Never consume previously prescribed leftovers.

Discard them.. If side effects occur from the course of antibiotics or if the condition shows no signs of improvement, see your physician again..

Keep capsules or tablets in a cool dry place. Store liquid mixtures in the refrigerator



Antibiotics, sometimes known as antibacterials, are drugs used to treat infections caused by bacteria. These are tiny organisms, too small to see with the naked eye, that sometimes cause illness in humans. Well-known illnesses caused by bacteria include tuberculosis, salmonella, syphilis and some forms of meningitis. However many types of bacteria do not cause illness and live harmlessly on, and in, the human body.

Our immune systems, with their antibodies and special white blood cells, can usually kill harmful bacteria before they multiply enough to cause symptoms. And even when symptoms do occur, the body can often fight off the infection. But sometimes the body is overwhelmed by a bacterial infection and needs help to get rid of it. This is where antibiotics come in. The very first antibiotic was penicillin and along with a family of related antibiotics (such as ampicillin, amoxicllin and benzylpenicillin) it is still widely used to treat many common infections. Now there are several other different kinds of antibiotics. All of them are only available on prescription.

How do antibiotics work?
What are antibiotics for?
Side effects of antibiotics
Use antibiotics with care if ...
Interactions with other medicines
How to use an antibiotic
Common antibiotics

How do antibiotics work?

Some antibiotics, such as the penicillins, are 'bactericidal', meaning that they work by killing bacteria. They do this by interfering with the formation of the cell walls or cell contents of the bacteria. Other antibiotics are 'bacteriostatic', meaning that they work by stopping bacteria multiplying.

What are antibiotics for?

Antibiotics are usually used to treat infections caused by bacteria. They do not work against other organisms such as viruses or fungi. It's important to bear this in mind if you think you have some sort of infection, because many common illnesses, particularly of the upper respiratory tract such as the common cold and sore throats, are usually caused by viruses. Overuse of antibiotics can lead to bacteria becoming resistant to them so it's important to only take them when necessary. (see below).

Some antibiotics can be used to treat a wide range of infections and are known as 'broad-spectrum' antibiotics. Others are only effective against a few types of bacteria and are called 'narrow-spectrum' antibiotics. Some antibiotics work against aerobic bacteria, that is organisms that need oxygen to live, while others work against anaerobic bacteria, organisms that don't need oxygen. Sometimes antibiotics are given to prevent an infection occurring, for example, before certain operations. This is known as prophylactic use of antibiotics and is common before orthopaedic and bowel surgery.

Side effects of antibiotics

The most common side effects with antibiotic drugs are diarrhoea, feeling sick and being sick.

Fungal infections of the mouth, digestive tract and vagina can also occur with antibiotics because they destroy the protective 'good' bacteria in the body (which help prevent overgrowth of any one organism), as well as the 'bad' ones, responsible for the infection being treated.

Rare, but more serious side effects, include the formation of kidney stones with the sulphonamides, abnormal blood clotting with some of the cephalosporins, increased sensitivity to the sun with the tetracyclines, blood disorders with trimethoprim, and deafness with erythromycin and the aminoglycosides.

Sometimes, particularly in older people, antibiotic treatment can cause a type of colitis (inflamed bowel) leading to severe diarrhoea. Penicillins, cephalosporins and erythromycin can all cause this problem but it is most common with clindamycin, an antibiotic usually reserved for serious infections. If you develop diarrhoea while taking an antibiotic, immediately contact your doctor.
Some people are allergic to antibiotics, particularly penicillins, and can develop Side effects such as a rash, swelling of the face and tongue, and difficulty breathing when they take them. Always tell your doctor or pharmacist if you have had an allergic reaction to an antibiotic; sometimes the reaction can be serious or even fatal. This is called an anaphylactic reaction.

Use antibiotics with care

You should use an antibiotic with care if you have reduced liver or kidney function. You should avoid using any antibiotic to which you have previously had an allergic reaction.
Tell your doctor or pharmacist if you are pregnant or breastfeeding before taking any antibiotic.

Interactions with other medicines

Do not take any other medicines or herbal remedies with an antibiotic, including those you have bought without a prescription, before talking to your doctor or pharmacist.

Certain antibiotics (e.g. penicillins, cephalosporins) can reduce the effectiveness of oral contraceptives. If you have diarrhoea or vomiting while taking an antibiotic, the absorption of the pill can be disrupted. In either case, you should take additional contraceptive precautions while you are taking the antibiotic.

There are a number of important interactions between antibiotics and other medicines so it's important to tell which your doctor or pharmacist about any other medicines you are taking.

How to use an antibiotic

Antibiotics are usually taken orally but can also be given by injection, or applied to the affected part of the body such as the skin, eyes or ears. The drugs begin to tackle most infections within a few hours. It is vital to take the whole course of treatment to prevent recurrence of the infection. Sometimes bacteria become 'resistant' to an antibiotic you have been taking, meaning that the drug will no longer work. Resistance tends to occur when the bacterial infection responsible for the symptoms is not completely cured, even if the symptoms have cleared up. Some of the residual bacteria, having been exposed to, but not killed by, the antibiotic are more likely to grow into an infection that can survive that particular antibiotic. This explains why finishing the course of antibiotics, even if you feel better, is important.

Certain antibiotics should not be taken with certain foods and drinks. Some antibiotics are best taken when there is no food in your stomach, usually an hour before meals or two hours after - make sure you follow the instructions on the dispensing label. Do not drink alcohol if you are taking metronidazole. Do not take tetracyclines with dairy products, as these can reduce the absorption of this type of antibiotic.


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