Understanding antibiotics

Posted on 19 February 2015

Douglas Defty, pharmacy services executive at Mediclinic, helps us understand antibiotics.

How do antibiotics work?
It’s important to understand that an antibiotic only acts against a bacteria and not a virus. The first thing people think when they’ve got a snotty nose or cough is that they need an antibiotic. According to the Centers for Disease Control and Prevention, viruses cause common illnesses that antibiotics cannot treat like:

• Colds
• Influenza (the flu)
• Runny noses
• Most coughs
• Most bronchitis
• Most sore throats
• Most sinus infections
• Some ear infections

Viral illnesses, like colds, usually go away without treatment in a week or two. Even many bacterial ear infections go away by themselves. When an antibiotic is not prescribed, ask your doctor or pharmacist what can be used to relieve symptoms.

Antibiotic resistance is a major threat to healthcare – not only in South Africa, but globally. Antibiotics and similar drugs, together called antimicrobial agents, have been used for the last 70 years to treat patients who have infectious diseases. Since the 1940s, these drugs have greatly reduced illness and death from infectious diseases. However, these drugs have been used so widely and for so long that the infectious organisms the antibiotics are designed to kill have adapted to them, making the drugs less effective.   Antibiotic use can result in an antibiotic-resistant infection. Resistant bacteria are stronger and harder to kill – they can stay in your body and can cause severe illnesses that can’t be cured with antibiotics. A cure for a resistant infection may require stronger treatment – and possibly a hospital stay.

So instead of needing antibiotics, you need to treat the symptoms – the runny nose, the cough, the fever.

Why should I take the course of antibiotics until it’s finished, even when I start to feel better?
If antibiotics are prescribed for you to treat a bacterial infection be sure to take all of the medicine. Only using part of the prescription could mean that only part of the infection has been treated. Don’t skip any doses as this will result in too low blood levels of the drug to kill the bacteria, causing resistance. And as a result, particular antibiotic will no longer work. Always finish your course – never dump it down the drain or share it with someone. What often happens is you have a couple left and someone else starts to feel sick, and you say: ‘Well I was sick last week and got an antibiotic and it worked for me. Take it.’ But what’s to say the antibiotic was warranted in the first place? It could have been a viral infection that was naturally self-limiting. Bottom line – take your medication exactly as it has been prescribed to you even if you’re feeling better – you shouldn’t have any left over.

My doctor said I mustn’t drink while on antibiotics but surely it’s okay to have just one?
Certain antibiotics, such as Flagyl, blocks the processing of alcohol in the body – which means if you take the antibiotic and drink alcohol you’ll be horribly sick. Plus, when you’re ill you shouldn’t be going out partying anyway – alcohol inhibits your immunity and you should be at home resting! Alcohol also causes dehydration and when you’ve got flu you should be drinking lots of water.

Is it okay to take antibiotics while you’re pregnant?
It’s always best to use antibiotics wisely whether you are pregnant or not due to the increasing resistance of bacteria to antibiotics. The safety of antibiotics in pregnancy is dependent on the specific class of antibiotic. Penicillin is generally regarded as a safe antibiotic during pregnancy. Other classes such as Tetracyclines can cause fetal tooth discoloration after the first trimester. Aminoglycosides increase the risk for ototoxicity (hearing disorder) and Chloramphenicol can cause a syndrome named Grey baby syndrome.   Antibiotics should only be taken when prescribed by a doctor who is familiar with your pregnancy. It is best to consult your doctor on the safety of the particular drug prescribed in your specific stage of pregnancy.

 

 

The information provided in this article was correct at the time of publishing. At Mediclinic we endeavour to provide our patients and readers with accurate and reliable information, which is why we continually review and update our content. However, due to the dynamic nature of clinical information and medicine, some information may from time to time become outdated prior to revision.