Side effects

We take medicines to make us better, but all medicines can cause unwanted secondary effects which are called side-effects.

Side-effects are a common cause of illness, discomfort and distress in people taking anti-HIV drugs – even in people who have an undetectable viral load and high CD4 cell count and don’t have any symptoms of HIV infection.

However, it’s not inevitable that you will experience side-effects from any of the medicines you are given to fight HIV or other infections. It’s also worth remembering that a lot of side-effects are mild, lessen or even go away over time, and can often be controlled with other medicines.

There are two main reasons for side-effects: an allergic reaction to the drug which causes side-effects, or side-effects caused by the direct effects of a medicine.

An allergic reaction can involve symptoms such as a rash or fever. You should contact your doctor immediately if you suspect that you have developed an allergic reaction to any medicine you are taking. An allergic (hypersensitivity) reaction to abacavir (Ziagen) or nevirapine (Viramune) can be very dangerous. If you are taking abacavir you should read carefully the warning card that comes with boxes of the medicines and contact your doctor immediately if you experience any symptoms suggesting that you might be experiencing an allergic reaction to the drug.

If a side-effect is being caused by the unwanted effects of a drug itself, the nature of the side-effect might depend on which part of the body the drug is intended to treat, or the way in which the body processes the drug. Some medicines can make you feel generally unwell, or cause vomiting, nausea, or diarrhoea. Reduced sex drive or sexual problems are another common side-effect.

Side-effects are often related to the amount of drug you are taking – for some drugs, but not all, it is possible to adjust the dose you receive to help mininise the risk of side-effects.

Side effects soon after starting treatment

Most side-effects occur after you have been taking a medicine for a week or two. However, there is no strict pattern, and some people develop side-effects after taking their first dose of a drug. For others, side-effects don’t develop for many months.

Side-effects occur in the first month or so of taking a drug not because you are being poisoned by the medicine, but because your body is getting used to the drug. Over time, your body gets used to the medicine, and side-effects tend to wear off.

 

Daily pattern to side effects

There can be a daily pattern to side-effects, linked to the time you take your medicines and also to the processing of the drug by your body. It might be possible to minimise the inconvenience that this causes by adjusting the time at which you take your medicines. For example, the NNRTI efavirenz (Sustiva) can cause dizziness and other psychological side-effects. Many people overcome these by taking their daily dose of the drug just before going to bed.

Medicines to control side effects

Medicines are available to help control side-effects in both the short and the long term. These include anti-sickness and anti-diarrhoea drugs and when needed, antidepressants or painkillers.

Longer term side effects

Some anti-HIV treatment has also been linked to an increased risk of bone problems, heart disease, kidney problems and liver disease. After starting HIV treatment you’ll have regular blood tests to see if you’re at risk of developing any serious side-effects, and you should mention any unusual symptoms to your doctor.

Some older HIV drugs that aren't used very much in this country called a collection of side-effects known as, lipodystrophy, changes in body shape and blood fats. Some now rarely-used anti-HIV drugs have also been associated with a rare, but serious long-term side-effect is called lactic acidosis.

It’s recommended that you start treatment when your CD4 cell count is around 350. Starting treatment at this level reduces the risk of HIV-related illnesses and some other serious illness as well. It also seems to reduce the risk of some serious side-effects.

 

Changing treatment

You’re doctor can usually do something about side-effects, so it makes good sense to mention any that you’re experiencing. Don’t stop taking treatments without seeking medical advice.

If it’s known that a particular anti-HIV drug is causing side-effects, then it’s likely, particularly if you’ve never taken anti-HIV drugs before, that you will be able to change treatment to a drug that doesn’t cause the side-effects you are experiencing.