Adverse drug reactions

While medicine can make a huge improvement to our health, there are times when the medicine may make us feel unwell. Before a medicine is available for human use, the benefits of a medicine are weighed up against how likely it is to make people feel unwell.

Why put up with side effects?
Government medicine regulation departments decide if a medicine is safe enough to be available in their country. They look at how unwell the person would need to be to take this medicine. If you are going to die from not taking it then it is probably OK to get an upset tummy for a few days. If you have a head cold that will go away next week then the medicine has to be a lot safer and less likely to cause a side effect.

How common:
The World Health Organization (WHO) states that a side effect is an unintended response to a drug when the drug was taken in a normal dose. So this is not the same as an overdose and it is not about interacting with other medicines. It is to do with just this one medicine and how our body responds to it.

Side effects are classed as very common, common, uncommon, rare and very rare. The very common side effects are things that happen in one person of every 10 people taking that medicine. Uncommon side effects happen in one person per thousand, very rare side effects happen in less than one person for every 10,000 people taking that medicine.

Medicines that have been on the market for a long time are likely to have most if not all of their side effects known. When a drug is new there might be side effects that have not yet been identified.

What to do and what else to consider:
If you think you are having a side effect to your medicine it is important to tell you doctor or pharmacist.

Often it is more dangerous to stop a medicine. Always consider why you are taking the medicine. If you are taking it for a heart problem and not taking may cause your heart to stop then clearly you would put up with a minor side effect (like a little bit of dizziness) until you can get to the doctor to discuss it. If you are taking something for mild hayfever and you think you are having a reaction to the medicine then it is probably safe to stop the medicine until you get to the doctor.

When reporting a side effect it is important to list all medicines and natural therapies you are taking. Some medicines or natural therapies will be fine by themselves but might cause a problem when used together.

Drug interactions:
Drug interactions are when you are taking two or more medicines that are each fine by themselves but together can cause a problem.

If you are buying a medicine in a pharmacy please let the pharmacist know what other medicines you are on so that they can help you choose something that is safe. Another tip is that you should always use the same pharmacy even if you go to several doctors. Many people go to one GP but one or more specialists. Dentists and optometrists can also prescribe medicine. By always using the same pharmacy they will have a full list of all of your medicines and can advise on interactions and potential side effects of your medicines.

Written by Linda Caddick

This blog provides general information and discussion about medicine, health and related subjects. The information contained in the blog and in any linked mate­ri­als, are not intended nor implied to be a substitute for professional medical advice.