Comparative Pharmacology
Head-to-head clinical analysis: EMTRICITABINE AND TENOFOVIR ALAFENAMIDE FUMARATE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMTRICITABINE AND TENOFOVIR ALAFENAMIDE FUMARATE versus EMTRIVA.
EMTRICITABINE AND TENOFOVIR ALAFENAMIDE FUMARATE 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 incorporates into viral DNA, causing chain termination. Tenofovir alafenamide is a nucleotide reverse transcriptase inhibitor (NtRTI) that is converted intracellularly 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 (emtricitabine 200 mg / tenofovir alafenamide fumarate 25 mg) orally once daily.
Emtricitabine 200 mg orally once daily.
None Documented
None Documented
Emtricitabine: terminal half-life ~10 hours; Tenofovir alafenamide: terminal half-life ~0.51 hours (rapid conversion to tenofovir); Intracellular tenofovir-diphosphate half-life >60 hours. Clinical context: daily dosing achieves steady state in 7 days.
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% excreted unchanged in urine, 14% as metabolites via urine. Tenofovir alafenamide: <1% excreted unchanged in urine; majority metabolized to tenofovir, which is eliminated renally via glomerular filtration and active tubular secretion. Overall, renal elimination is predominant.
Renal excretion of unchanged drug (~86%) by glomerular filtration and active tubular secretion; fecal excretion (<1%)
Category A/B
Category C
NRTI
Antiretroviral, NRTI