Abacavir with lamivudine

How it works

Both components are nucleoside analogues that, after intracellular phosphorylation, are incorporated into viral DNA by reverse transcriptase and cause chain termination, suppressing HIV replication.

Prescribing in practice

• Test for HLA-B*57:01 before initiation and do not use in carriers or anyone with previous abacavir hypersensitivity, given the risk of a severe and potentially fatal reaction on re-exposure.
• Avoid this fixed-dose product where lamivudine requires dose reduction, such as in significant renal impairment, and prescribe the individual components instead.
• An appropriate third active antiretroviral agent must always be co-prescribed, as this combination alone does not constitute a complete regimen.

Monitoring

Monitor HIV viral load, CD4 count and renal function, and review for any signs of hypersensitivity, particularly in the first weeks.

Counselling the patient

• Keep your hypersensitivity alert card with you and seek urgent advice if you develop fever or rash.
• Never restart abacavir after a suspected reaction unless specifically advised by the HIV team.
• Take the tablet regularly to maintain viral suppression and reduce resistance.

Evidence & guidelines

MHRA guidance mandates HLA-B*57:01 screening before abacavir use, and this nucleoside backbone is well established within combination antiretroviral therapy in UK HIV treatment guidelines.