Antibiotics are antibacterial drugs. They are used to fight a range of infections caused by bacteria.
The discovery of antibiotics is one of the greatest landmarks in the history of modern medicine. It has saved countless lives and permanently transformed the practice of medicine.

The first antibiotic – penicillin - was discovered by Sir Alexander Flemming in 1928 from his observation of a mould called penicillium. Flemming observed that the mould produced certain chemicals that were capable of killing most of the bacteria around it. Since this discovery, many other antibiotics have been developed, providing a cure for many previously fatal diseases such as tuberculosis, meningitis and pneumonia.

Although the first antibiotics were produced from moulds, many are now manufactured synthetically.

Are antibiotics effective against all illnesses?

Antibiotics only work against infections that are caused by bacteria. Most common infections such as colds, bronchitis and sore throats are caused by viruses and will not respond to treatment by antibiotics. In fact, taking antibiotic drugs to fight viral infections may cause side effects and will make your body more resistant to treatment so that when you do have a bacterial infection, your antibiotics may not work as well as they should.

Some viral infections such as herpes infection, some cases of influenza, and HIV/AIDS can be treated with antiviral drugs.

Based on your illness and symptoms (and laboratory tests, if necessary), your doctor can determine if prescribing an antibiotic is appropriate. There are many different antibiotics. Some are effective against only certain types of bacteria while others can effectively fight a wider range of bacteria (broad-spectrum antibiotics). Your doctor will then select the antibiotic that will work best for your infection.

What are the possible side effects?

When taken properly, most antibiotics will not harm us. However, as with all drugs, there is the possibility of side effects including nausea, diarrhoea and stomach pain.

As well as fighting the bad bacteria that is making you unwell, some antibiotics kill naturally occurring “friendly” bacteria that are needed by the body, causing diarrhoea or yeast infections such as thrush.
In some people, an allergic reaction (characterised by rash and itching, or in severe cases, difficulty breathing) can occur.

If you are prescribed an antibiotic be sure to ask your doctor about possible side effects. If you experience any side effects when you are taking an antibiotic, you should consult your doctor.

Consult with your doctor before taking any other medications (including over-the-counter medications). Some antibiotics might interact with your other medications e.g. warfarin, contraceptive pills etc. Always bring the list of your medications whenever you come and see your doctor. You should never take antibiotics given to you by someone else or prescribed for a previous illness.

Can bacteria become resistant to antibiotics?

Antibiotics, when taken properly, help to cure infection. However, due to overuse and misuse of these drugs over the years, some bacteria are now developing a resistance to antibiotics. These bacteria are commonly referred to as “superbugs”. If this trend continues, there is a danger that some bacterial infections will become untreatable. Resistance is most likely to develop after long-term treatment with an antibiotic or with antibiotics that kill a wide variety of bacteria.

To help ensure that your antibiotic treatment will be effective you should follow these basic guidelines:

• Take the correct dosage

If the dosage of the antibiotic is not adequate, it will not be effective for treatment of the infection and bacteria are more likely to develop resistance. This is because the bacteria can continue to grow and develop ways to disrupt the antibiotic's effects.

• Finish the full course as prescribed by your doctor

Many times, patients will stop the use of an antibiotic when they begin to feel better and it seems that the illness has gone. However, even after the symptoms are gone, the bacteria may still be present in small amounts and an infection can return if you stop taking your antibiotics before the end of the course. Not completing the prescribed dose may also promote resistance.

• Antibiotics should not be saved and reused.

You should always take the full course of antibiotic treatment, so none of the drug should be "left over." However, if this has occurred the antibiotics should not be taken to treat any other illness. Different types of infections require different types of antibiotics, so taking leftover medications is often not effective.

• Don’t expect a prescription every time you go to the doctor.

Due to the threat of antibiotic resistance, doctors are now more cautious when prescribing antibiotic drugs to treat illness. Trust your doctor’s judgement and don’t expect a prescription every time you feel unwell. Remember that common illnesses such as colds, flues and sore throats are caused by viral infections and will not respond to treatment by antibiotics.