ABAKAST-L Tablets ABAKAST-L is a fixed-dose antiretroviral combination of Abacavir and Lamivudine, both carbocyclic synthetic nucleoside reverse transcriptase inhibitors (NRTIs). Intracellularly, abacavir is converted to carbovir triphosphate and lamivudine to lamivudine 5'-triphosphate. Both active metabolites compete with natural nucleosides for incorporation into viral DNA via HIV-1 reverse transcriptase, acting as chain terminators to halt viral DNA synthesis and prevent replication. It is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 25 kg. Screening for the HLA-B*5701 allele is recommended prior to initiation to prevent hypersensitivity reactions.