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HealthInfo Waitaha Canterbury

Overview of antibiotics

He aha ngā rongoā paturopi me ka pēhea ērā e ora ai?

You have many bacteria (a type of bug or germ) in your body, especially in your gut (digestive tract). Some of these bacteria help keep you healthy. But these and other bacteria can cause infections in different parts of your body including your lungs (pneumonia) and bladder (urinary tract infection).

Antibiotics are medicines that treat infections caused by bacteria. Antibiotics are sometimes called antibacterials.

Not all infections are caused by bacteria, and some infections get better by themselves.

Antibiotics do not treat infections caused by viruses, which are another type of germ.

Antibiotics work by killing or reducing the growth of bacteria. They can affect the bacteria that cause an infection, but they can also kill your good bacteria at the same time.

Taking antibiotics can also cause unwanted effects and can lead to problems with resistant bacteria, especially if not used correctly.

Taking antibiotics

It's important to follow the instructions you get with your antibiotics, which will be on the label of your medicine box or bottle. If you aren't sure, check with your pharmacist.

There are several different antibiotics and each needs to be taken in a different way to work well. Some are taken once a day, others more often. Some need to be taken on an empty stomach, and others with food.

It's important to follow the instructions you've been given for taking your antibiotic.

Only take the antibiotics prescribed for you. Do not take other people's antibiotics and do not give your antibiotics to other people. This is because not all antibiotics work for all infections, and they may cause unpleasant side effects or even serious side effects.

If you're asked to finish all your antibiotics, do so even if you feel better.

Return unwanted or leftover antibiotics to your community pharmacy. Do not dispose of them down the toilet or sink or in your general household rubbish. For more information, see Safe use, storage & disposal of medicines.

Possible side effects of antibiotics

Not everybody gets side effects from taking antibiotics. But some people do get side effects, which often happen because the antibiotic has also killed good bacteria. Common side effects are:

If you have bad vomiting or diarrhoea, you may not absorb the antibiotic properly, or you may be getting sicker. Seek help from the health professional who gave you the antibiotics.

Antibiotics can also have more serious side effects, such as liver problems or life-threatening allergies. These are rare, but if you think you're having a serious side effect call an ambulance or see your GP urgently.

Antibiotic resistance

Bacteria can change when they come into contact with antibiotics – they can change so much that the antibiotics no longer affect them. This is called antibiotic resistance.

Antibiotic resistance bacteria (sometimes called superbugs) can lead to some serious infections that are very hard to treat or that we cannot treat at all (often called superbugs). This is important for your own health and for the health of the people around you.

We need antibiotics to treat serious infections caused by bacteria, like meningitis and pneumonia. So, it's really important to only take them when you need them.

Antibiotic allergies

Make sure to tell your doctor or healthcare provider if you think you've had an allergic reaction to any antibiotics in the past or had any side effects, even if they seemed minor. This will help ensure you get the best antibiotic to treat your infection.

If you develop a rash while taking an antibiotic, you should stop taking the antibiotic and contact your doctor or healthcare provider.

Antibiotics and alcohol

It's best to avoid drinking alcohol while you take antibiotics. This is because the alcohol can make the side effects like nausea and diarrhoea worse. Drinking alcohol when taking an antibiotic called metronidazole (Flagyl) may make you feel especially unwell and cause flushing in your face and a racing heart.

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Written by HealthInfo clinical advisers. Last reviewed May 2022.


Page reference: 307392

Review key: HIANT-307383