A feeling of wanting to vomit or be sick.

Causes

These are multiple but in HIV infection are most commonly due to stomach problems such as diarrhoeal illness, drugs, acute infections and emotional problems such as anxiety.

What to do

If the nausea is associated with other symptoms, the underlying cause needs to be investigated and treated. If it is due to drugs then the dose and frequency may need to be altered or the drug discontinued.

Nausea is a common drug side effect; it has been reported with almost every anti-HIV drug apart from the NNRTIs, and is particularly common with AZT, ddI and the protease inhibitors. It is also a very common experience during treatment with cancer drugs (chemotherapy).

Anti-nausea medication (anti-emetics), either as tablets or injections can be prescribed and may be necessary, especially if a specific drug treatment needs to be continued (such as high dose co-trimoxazole).

You can be prescribed anti-nausea medication before you start treatment as a back-up. In most cases, nausea begins to go away after a few weeks as your body adjusts to the medication. Medication usually starts with domperidone (10-20mg every 4-8 hours) or metoclopramide (also available in slow release form, which means you don't need to take so many tablets). A liquid form of metoclopramide is available, which can also be used in children. Metoclopramide may cause tiredness, dizziness or sleeplessness in some cases.

An alternative for the control of mild nausea is ginger tea or tablets, although these have not been tested for their effect on nausea caused by HIV medication.

More severe nausea - or nausea that does not respond to the drugs above - may be treated with prochlorperazine or ondansetron. Ondansetron may cause headache, dizziness, slight drowsiness or constipation. The cannabinoid drug nabilone may be prescribed if these drugs do not work.

Taking medicines after vomiting

If the medicine is taken on an empty stomach (e.g. ddI):

• If you vomit less than one hour after taking the drug(s), take again

• If you vomit more than one hour after taking the drug(s), do not take again

• If you can see the capsule or tablet in the vomit, take it again

If the medicine is taken with food:

• If you vomit less than three hours after taking the drug(s), take again

• If you vomit more than three hours afterwards, do not take again

If you can see the capsule or tablet in the vomit, take it again.

See also: Anorexia.