Comparative Pharmacology
Head-to-head clinical analysis: EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
EMTRICITABINE AND TENOFOVIR DISOPROXIL 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 inhibits HIV reverse transcriptase by competing with natural substrate and causing chain termination. Tenofovir disoproxil fumarate is a prodrug of tenofovir, an acyclic nucleoside phosphonate diester analog of adenosine monophosphate; it inhibits HIV reverse transcriptase and hepatitis B virus polymerase by incorporating into DNA and causing chain termination after conversion to tenofovir diphosphate.
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 (200 mg emtricitabine/300 mg tenofovir disoproxil fumarate) orally once daily.
Emtricitabine 200 mg orally once daily.
None Documented
None Documented
Emtricitabine: Terminal elimination half-life is approximately 10 hours (range 8-14 hours) in patients with normal renal function; prolonged to >200 hours in severe renal impairment. Tenofovir: Terminal elimination half-life of tenofovir is approximately 17 hours (range 12-18 hours) in patients with normal renal function; prolonged in renal impairment. Clinically, the long half-life supports 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% excreted unchanged in urine via glomerular filtration and active tubular secretion; 14% metabolized to 3'-sulfoxide diastereomers and glucuronide conjugates, with <1% excreted in feces. Tenofovir disoproxil fumarate: Tenofovir is eliminated by a combination of glomerular filtration and active tubular secretion, with 70-80% of the dose recovered as unchanged tenofovir in urine within 72 hours; renal excretion is the primary route.
Renal excretion of unchanged drug (~86%) by glomerular filtration and active tubular secretion; fecal excretion (<1%)
Category A/B
Category C
NRTI
Antiretroviral, NRTI