Comparative Pharmacology
Head-to-head clinical analysis: ABACAVIR AND LAMIVUDINE versus EMTRICITABINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ABACAVIR AND LAMIVUDINE versus EMTRICITABINE.
ABACAVIR AND LAMIVUDINE vs EMTRICITABINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Abacavir is a carbocyclic synthetic nucleoside analogue. Intracellularly, it is phosphorylated to carbovir triphosphate, an analogue of deoxyguanosine-5'-triphosphate (dGTP). Carbovir triphosphate inhibits the activity of HIV-1 reverse transcriptase (RT) by competing with the natural substrate dGTP and by incorporating into viral DNA, causing chain termination. Lamivudine is a synthetic nucleoside analogue. Intracellularly, it is phosphorylated to lamivudine triphosphate, which inhibits HIV-1 RT via DNA chain termination after incorporation into viral DNA. Both drugs are nucleoside reverse transcriptase inhibitors (NRTIs).
Nucleoside reverse transcriptase inhibitor; phosphorylated to emtricitabine triphosphate which competes with endogenous deoxycytidine triphosphate and incorporates into viral DNA causing chain termination.
One tablet (600 mg abacavir/300 mg lamivudine) orally once daily.
200 mg orally once daily, typically in combination with other antiretroviral agents.
None Documented
None Documented
Clinical Note
moderateEmtricitabine + Ribavirin
"Emtricitabine may increase the hepatotoxic activities of Ribavirin."
Clinical Note
moderateLamivudine + Emtricitabine
"The risk or severity of adverse effects can be increased when Lamivudine is combined with Emtricitabine."
Clinical Note
moderateGanciclovir + Emtricitabine
"The risk or severity of adverse effects can be increased when Ganciclovir is combined with Emtricitabine."
Clinical Note
moderateValganciclovir + Emtricitabine
Abacavir: ~1.5 h; Lamivudine: 5–7 h in adults, prolonged to ~9 h in children. Clinically, twice-daily dosing maintains therapeutic concentrations.
Terminal elimination half-life is approximately 10 hours (range 8–12 hours) in adults with normal renal function; prolonged to >20 hours in severe renal impairment (CrCl <30 mL/min).
Abacavir: 83% renal (primarily as metabolites via alcohol dehydrogenase and glucuronidation), 16% fecal. Lamivudine: ~70% renal as unchanged drug via active tubular secretion.
Renal: approximately 86% of the dose is excreted unchanged in urine via glomerular filtration and active tubular secretion. Biliary/fecal: minimal (<14% as unchanged drug and metabolites in feces).
Category A/B
Category C
NRTI
Antiretroviral, NRTI
"The risk or severity of adverse effects can be increased when Valganciclovir is combined with Emtricitabine."