Anti-HIV drugs can cause side-effects in anyone. But that doesn’t mean that you will definitely experience side-effects – in fact many people who take HIV treatment don’t have any side-effects at all.

The type and severity of side-effects can also vary between people.

Some people find that, although they have side-effects, these are mild and they can live with them without inconvenience or they go away completely after a while.

However, a small number of people find that side-effects are a permanent feature of a particular HIV drug and affect their quality of life, even going so far as causing physical or mental illness.

Your risk of developing some side-effects can be affected by some genetic factors.

For example, some people have a particular gene (HLA-B*5701) which puts them at risk of a severe allergic (hypersensitivity) reaction to the anti-HIV drug abacavir. There is a test to find out if you have that gene, which your doctor will arrange if you are considering treatment with abacavir. If you do have the gene, you must not take abacavir – see Hypersensitivity (allergic) reactions for more information.

Another such factor is ethnic background. For example, some people process efavirenz more slowly than others. This is thought to be linked to a genetic variation which is common in black African people. It can increase the risk of side-effects.

Sometimes, taking other medications or drugs, including over-the-counter, herbal or recreational drugs, at the same time as anti-HIV drugs can increase the chances of having side-effects.

Lifestyle factors might also affect your risk of some other side-effects. Some anti-HIV drugs, for example, can cause increases in blood fats, and this could be made worse if you eat lots of high-fat foods. There is some concern that treatment with some anti-HIV drugs might increase the risk of cardiovascular disease, and this can be a real concern for people with other risk factors for heart disease such as smoking or a family history of heart disease.

Other HIV drugs have been linked with liver problems, and these can also be caused by drinking too much alcohol or using recreational drugs. Having hepatitis B or hepatitis C can also mean that you have an increased risk of developing liver problems if you are taking certain anti-HIV drugs.

There are actions, many of which have other health benefits as well, that you can take to reduce the risk of developing certain side-effects. These include eating a balanced diet (with lots of fresh fruit and vegetables and not too much fat), doing regular exercise, not smoking, and not drinking too much alcohol. You can find out more about these in NAM’s booklet Nutrition.

If you have risk factors for side-effects (for example, hepatitis B or C, or a family history of heart disease), it is important that your doctor knows about them. This will enable you and your doctor to find the most suitable anti-HIV drugs for you. NAM’s online tool, Talking points, can help you prepare for this discussion with your doctor by taking you through the health and lifestyle factors that might affect your choice of anti-HIV drugs.