Comparative Pharmacology
Head-to-head clinical analysis: ABACAVIR SULFATE LAMIVUDINE versus ABACAVIR SULFATE LAMIVUDINE AND ZIDOVUDINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ABACAVIR SULFATE LAMIVUDINE versus ABACAVIR SULFATE LAMIVUDINE AND ZIDOVUDINE.
ABACAVIR SULFATE; LAMIVUDINE vs ABACAVIR SULFATE, LAMIVUDINE AND ZIDOVUDINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Abacavir is a nucleoside reverse transcriptase inhibitor (NRTI) that, after intracellular phosphorylation to carbovir triphosphate, competes with natural deoxyguanosine triphosphate for incorporation into viral DNA, causing chain termination. Lamivudine is an NRTI that, after phosphorylation to lamivudine triphosphate, inhibits HIV-1 reverse transcriptase via incorporation into viral DNA, resulting in chain termination.
Abacavir is a carbocyclic synthetic nucleoside analog guanosine analogue that is phosphorylated to carbovir triphosphate, which inhibits HIV-1 reverse transcriptase by competing with natural substrate dGTP and causing chain termination. Lamivudine is a dideoxy-nucleoside cytidine analogue that is phosphorylated to lamivudine triphosphate, which inhibits HIV-1 reverse transcriptase via incorporation into viral DNA and chain termination. Zidovudine is a thymidine analogue that is phosphorylated to zidovudine triphosphate, which inhibits HIV-1 reverse transcriptase by competing with dTTP and causing chain termination. All three drugs are nucleoside reverse transcriptase inhibitors (NRTIs).
One tablet (abacavir 600 mg/lamivudine 300 mg) once daily, in combination with other antiretrovirals.
One tablet (abacavir 600 mg/lamivudine 300 mg/zidovudine 300 mg) twice daily or as a single tablet once daily (abacavir 600 mg/lamivudine 300 mg/zidovudine 300 mg) depending on formulation.
None Documented
None Documented
Abacavir: 1.5 h; Lamivudine: 5-7 h (intracellular 10-15 h). Clinical context: Both support twice-daily dosing; lamivudine's longer intracellular half-life allows once-daily dosing.
Abacavir: 1.5 h; lamivudine: 5-7 h; zidovudine: 0.5-3 h. Terminal half-lives: abacavir ~1.5 h, lamivudine ~13-19 h intracellularly (active triphosphate), zidovudine ~1 h (plasma) but intracellular triphosphate ~3-4 h. Clinical context: Twice-daily dosing due to prolonged intracellular half-life of active metabolites.
Renal: Abacavir ~83% (metabolites), Lamivudine ~70% (unchanged). Fecal: Abacavir ~16%, Lamivudine minimal. Biliary: negligible.
Renal excretion of unchanged drug and metabolites: abacavir (83% as metabolites, 1% unchanged), lamivudine (70% unchanged), zidovudine (72-74% as metabolites, 14-18% unchanged). Biliary/fecal elimination is minor (<10% for each component).
Category A/B
Category A/B
NRTI
NRTI