Prescriptions Elinor Hardman Many people don't take the medicines their doctor prescribes, or fail to complete the course. This can put their own health - and that of other people - at risk. If you're unsure about anything to do with your prescription, ask your doctor or pharmacist.

In this article

Medicine interactions and misuse

Antibiotic resistance

Stopping medication

Medicines play an increasing role in our lives as we get older, controlling many conditions such as diabetes, high blood pressure and high cholesterol.

The annual independent campaign Ask About Medicines stresses that we need to ask more questions to ensure we use medicines safely and effectively.

Just a small increase in the number of medicines a person takes can make a big difference in how they react to one another. This could explain why as many as ten per cent of hospital admissions are thought to be due to the difficulties that older medicine users have with their prescriptions.

Pills and ills

• Aged 50, the average person takes three different medicines a year
• By the time we're 80, this has increased to more than eight different medicines a year
• As many as 50 per cent of older people may not be taking their medicines as intended

According to research, up to two-thirds of people with diabetes don't take their medication as prescribed, because they don't understand what their medication is for or feel stupid asking questions about it.

Failure to manage conditions such as diabetes can have serious consequences.

Not taking medicines in the way they're prescribed doesn't only affect individual patient's health, it can also have wider repercussions.

Most people have heard of the antibiotic-resistant 'superbugs' in hospitals and other health premises. These have developed for a number of reasons, one being that people aren't taking their drugs in the way their doctor has recommended.

There can be serious consequences for patients who don't complete their course of medicine as prescribed.

At the beginning of a bacterial infection, some bacteria will have a few resistance genes, some will have lots and some won't have any. The ones with the least resistance are wiped out first. If you carry on with your medicine, most of the strong ones will also be killed off as their capacities for defence are overwhelmed.

The problem occurs when a course of medicine isn't finished. The stronger bugs survive and may reinfect the patient or others. There are many genes that offer bacteria resistance to antibiotics in different ways.

When this happens, bacteria start swapping them prolifically, so that each will be as strong as it can be against the antibiotic that has failed to kill it.

There are many reasons why patients stop taking their prescribed medication, including:

• The drug's side-effects are making them feel ill
• They feel better (particularly with antibiotics and medications for mental illness)

If you want to stop taking your medication because of unpleasant side-effects, or for any other reason, talk it through with your doctor first. They'll be able to tell you how common the problems you're having are and may be able to work out an alternative.

They'll also tell you what the outcome is likely to be if you don't continue the medication. If you have any queries about your medication, it's crucial that you discuss this with your doctor or pharmacist.

This article was last medically reviewed by Dr Rob Hicks in February 2007.