Abacavir-d₄is intended for use as an internal standard for the quantification of abacavir by GC- or LC-MS. Abacavir is a nucleoside analog and an inhibitor of HIV-1 reverse transcriptase (K_i= 2.1 µM for the wild-type enzyme).¹It inhibits replication of a variety of HIV-1 and HIV-2 strains, including strains resistant to 3'-azido-3'-deoxythymidine or 2',3'-dideoxyinosine , in HeLa cells stably expressing CD4 (IC₅₀s = 5.8-21 µM). Abacavir inhibits replication of eight HIV-1 clinical isolates in phytohemagglutinin-stimulated isolated human peripheral blood lymphocytes with a mean IC₅₀value of 0.26 µM. It inhibits hepatitis B virus (HBV) DNA synthesis in HepG2 cells (IC₅₀= 7 µM) and is also active against human cytomegalovirus (CMV) strain AD169 and the Petaluma strain of feline immunodeficiency virus (FIV) in plaque reduction assays (IC₅₀s = 32 and 0.4 µM, respectively). Formulations containing abacavir have been used in the treatment of HIV infection.

1.Daluge, S.M., Good, S.S., Faletto, M.B., et al.1592U89, a novel carbocyclic nucleoside analog with potent, selective anti-human immunodeficiency virus activityAntimicrob. Agents Chemother.41(5)1082-1093(1997)