Comparative Pharmacology
Head-to-head clinical analysis: EMTRICITABINE TENOFOVIR ALAFENAMIDE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMTRICITABINE TENOFOVIR ALAFENAMIDE versus EMTRIVA.
EMTRICITABINE; TENOFOVIR ALAFENAMIDE vs EMTRIVA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) that is phosphorylated to emtricitabine triphosphate, which competes with the natural substrate deoxycytidine 5'-triphosphate and inhibits HIV-1 reverse transcriptase by incorporating into viral DNA, causing chain termination. Tenofovir alafenamide is a prodrug of tenofovir, an NRTI; it is converted to tenofovir, then phosphorylated to tenofovir diphosphate, which inhibits HIV-1 reverse transcriptase by competing with deoxyadenosine 5'-triphosphate and causing DNA chain termination.
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 orally once daily containing emtricitabine 200 mg and tenofovir alafenamide 25 mg.
Emtricitabine 200 mg orally once daily.
None Documented
None Documented
Emtricitabine: 10 hours (prolonged to ~40 hours in severe renal impairment, CrCl <30 mL/min). Tenofovir alafenamide: 0.51 hours (active metabolite tenofovir diphosphate has intracellular half-life of 150-180 hours in PBMCs, supporting once-daily dosing).
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)
Emtricitabine: 86% renal (active tubular secretion and glomerular filtration), 14% fecal. Tenofovir alafenamide: <1% renal, >97% fecal (as unchanged drug or metabolites, primarily via hepatobiliary excretion).
Renal excretion of unchanged drug (~86%) by glomerular filtration and active tubular secretion; fecal excretion (<1%)
Category A/B
Category C
NRTI
Antiretroviral, NRTI