Comparative Pharmacology
Head-to-head clinical analysis: ABACAVIR SULFATE LAMIVUDINE AND ZIDOVUDINE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ABACAVIR SULFATE LAMIVUDINE AND ZIDOVUDINE versus EMTRIVA.
ABACAVIR SULFATE, LAMIVUDINE AND ZIDOVUDINE vs EMTRIVA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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).
Nucleoside reverse transcriptase inhibitor; emtricitabine is phosphorylated to emtricitabine 5'-triphosphate which competes with deoxycytidine 5'-triphosphate for incorporation into viral DNA, resulting in chain termination.
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.
Emtricitabine 200 mg orally once daily.
None Documented
None Documented
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.
Terminal elimination half-life ~10 hours (mean 10 h, range 7-14 h) in adults; prolonged in renal impairment (up to 90 h in severe impairment)
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).
Renal excretion of unchanged drug (~86%) by glomerular filtration and active tubular secretion; fecal excretion (<1%)
Category A/B
Category C
NRTI
Antiretroviral, NRTI