The two nukes

Two nukes are the basis of most combinations, with both drugs usually in a single pill. These are once-daily drugs with a low risk of side effects.

* abacavir/lamivudine (Kivexa) and tenofovir/emtricitabine (Truvada) are already off-patent.  Generic versions of these drugs are likely to be widely used in the UK.

UK guidelines recommend TDF or TAF over abacavir, except when the third drug is dolutegravir.

Abacavir involves having a blood test first (called HLA B*5701) to rule out the small chance of a sensitivity reaction.

Abacavir should not be used if you have a high risk of heart problems.

TDF is widely used except in people who already have kidney or bone problems.

TAF is similar to TDF but with less impact on kidney and bone health. However, it is more expensive than either abacavir or TDF, both of which are either available as generics or will be shortly (see pages 39 to 49).

Lamivudine (3TC) and emtricitabine (FTC) are very similar drugs with few side effects. Either can be used, but they should not be taken together.

These are once-daily drugs with a low risk of side effects.

Nukes that don’t mix

Although one nuke can often be switched for another, some nukes that should never be used together in the same combinations.

Nukes that don’t mix
TDF AND TAF At any time
3TC and FTC At any time
abacavir and tenofovir Not in a 3-drug combo
Triple-nuke combinations Only two combinations: AZT+3TC+abacavir or AZT+3TC+tenofovir, can be used. Others have a high risk of failure.

Last updated: 1 October 2019.