Comparative Pharmacology
Head-to-head clinical analysis: EMTRIVA versus LAMIVUDINE ZIDOVUDINE ABACAVIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMTRIVA versus LAMIVUDINE ZIDOVUDINE ABACAVIR.
EMTRIVA vs LAMIVUDINE; ZIDOVUDINE; ABACAVIR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Lamivudine, zidovudine, and abacavir are nucleoside reverse transcriptase inhibitors (NRTIs). They are phosphorylated intracellularly to active metabolites that compete with natural nucleotides for incorporation into viral DNA, causing chain termination and inhibition of HIV reverse transcriptase.
Emtricitabine 200 mg orally once daily.
One tablet (300 mg abacavir, 150 mg lamivudine, 300 mg zidovudine) orally twice daily.
None Documented
None Documented
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)
Lamivudine: 5-7 hours (single dose), prolonged to ~11 hours in renal impairment; Zidovudine: 1.1 hours (terminal), increased to 1.4 hours in hepatic impairment; Abacavir: 1.5 hours (terminal), slightly prolonged in hepatic impairment; Clinical context: Dosing interval of 12 hours requires therapeutic drug monitoring in renal/hepatic dysfunction.
Renal excretion of unchanged drug (~86%) by glomerular filtration and active tubular secretion; fecal excretion (<1%)
Lamivudine: ~70% excreted unchanged in urine via glomerular filtration and active tubular secretion; Zidovudine: ~75% excreted as metabolites (primarily 5'-glucuronide) in urine, with <20% unchanged; Abacavir: ~83% excreted as metabolites in urine (via alcohol dehydrogenase and glucuronidation) and ~16% in feces; Total renal elimination accounts for >80% of clearance for all three components.
Category C
Category A/B
Antiretroviral, NRTI
NRTI