Acute side-effects

When you start taking anti-HIV drugs your HIV doctor will give you information and advice on any possible acute side-effects and will carefully monitor your progress. It's rare to have any acute side-effects, but if you do experience any then you should seek immediate medical attention.

Acute side-effects may include:

• hypersensitivity reactions
• Stevens-Johnson syndrome
• hyperlactataemia
• pancreatitis.

Remember: these are very rare, but if you have any concerns, speak to your doctor.

Hypersensitivity reactions

These are severe allergic reactions to HIV drugs that usually appear in the first six weeks or so of your therapy. In particular, two well-characterised hypersensitivity reactions are caused by the drugs abacavir and nevirapine.

Abacavir

The abacavir hypersensitivity reaction usually shows itself as rash, fever, diarrhoea and/or vomiting, muscle pain and sometimes chest congestion. Anyone starting on abacavir should seek immediate medical attention if these symptoms appear, but don't stop taking the drug immediately. If you do get a hypersensitivity reaction to abacavir, your doctor should take you off the drug. It is then very dangerous ever to take abacavir again, as this will produce a much worse hypersensitivity reaction.

Nevirapine

The nevirapine hypersensitivity reaction involves acute liver damage which, if left untreated, may proceed to liver failure, usually accompanied by fever. If this is going to happen, it always occurs in the first six to eight weeks of taking the drug. You might also get a rash but this does not indicate hypersensitivity in itself. Speak to your doctor immediately who should stop you taking nevirapine.

Stevens-Johnson syndrome

The symptoms of Stevens-Johnson syndrome are a severe rash accompanied by blistering. Your HIV therapy should be stopped immediately until this is sorted out.

Hyperlactataemia

This is an excess of lactic acid in the blood, which may develop into the life-threatening condition lactic acidosis, although this is very rare indeed. It feels like severe exhaustion with breathlessness, muscle pain and nausea. High doses of B vitamins with l-acetyl carnitine have been used successfully to treat it.

Pancreatitis

This is an inflammation of the pancreas, which can cause fatigue, central abdominal pain and nausea.