Other nukes

AZT and Combivir

AZT is a twice-daily nuke that has been widely used and studied, but is now only mainly used in first-line treatment during pregnancy.

Combivir is a fixed-dose combination of AZT and 3TC that is taken twice-daily.

The disadvantages of AZT are the side effects of anaemia, fatigue and lipoatrophy (fat loss). Lipoatrophy does not usually occur during the first six months of AZT treatment.

European guidelines do not recommend AZT as first-line choice, except for women who are pregnant or trying for a baby.

ddI

ddI is rarely used as a first-line choice because it needs to be taken on an empty stomach (ie two hours after food). This makes dosing inconvenient. ddI is mainly used in people with drug resistance.

Triple nuke combinations

Triple nuke combinations are not recommended as first-line treatment as they are less effective.

The main reason to use a triple nuke combination is to reduce side effects related to PIs or NNRTIs or if there are interactions between these drugs and other medications (ie for TB).

Nukes that dont mix

Although one nuke can often be switched for another, there are some combinations that should not be used.

Nuke pair	When not to use
AZT and d4T	At any time
FTC and 3TC	At any time
ddI and tenofovir	Especially with an NNRTI
abacavir and tenofovir	In a 3-drug combo until an interaction is explained
d4T and ddI	Never during pregnancy
Triple-nuke combinations	Only two combinations – AZT + 3TC + abacavir or AZT + 3TC + tenofovir – can be used. Others have a high risk of failure

This is the web edition of the i-Base guide Introduction to combination therapy. This guide is available in UK clinics. You can order free printed copies or download a PDF version (516 Kb). Translations. Authors and credits. Glossary. Full section index.

Decisions relating to your treatment should always be taken in consultation with your doctor. Information in this guide is intended to support those discussions.