Comparative Pharmacology
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE AND TENOFOVIR ALAFENAMIDE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE AND TENOFOVIR ALAFENAMIDE versus EMTRIVA.
EFAVIRENZ, EMTRICITABINE AND TENOFOVIR ALAFENAMIDE vs EMTRIVA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that binds directly and reversibly to the reverse transcriptase enzyme, causing a conformation change and inhibiting RNA-dependent and DNA-dependent DNA polymerase activity. Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) that is phosphorylated to its active triphosphate form, which competes with deoxycytidine triphosphate and incorporates into viral DNA, causing chain termination. Tenofovir alafenamide is a prodrug of tenofovir, an NRTI; it is taken up by hepatocytes and activated to tenofovir diphosphate, which inhibits reverse transcriptase by competing with deoxyadenosine 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 (600 mg efavirenz/200 mg emtricitabine/25 mg tenofovir alafenamide) orally once daily on an empty stomach, preferably at bedtime.
Emtricitabine 200 mg orally once daily.
None Documented
None Documented
Efavirenz: 52-76 h (single dose), 40-55 h (multiple doses). Emtricitabine: ~10 h. Tenofovir alafenamide: 0.51 h (parent drug), 32.4 h (tenofovir, terminal half-life).
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)
Efavirenz: 14-34% renal (as unchanged drug <1%), 16-61% fecal (as parent drug/metabolites). Emtricitabine: ~86% renal (as unchanged drug). Tenofovir alafenamide: <1% renal (as unchanged drug), ~31.5% fecal (as parent drug), remainder as tenofovir (metabolite) which undergoes renal filtration and active tubular secretion.
Renal excretion of unchanged drug (~86%) by glomerular filtration and active tubular secretion; fecal excretion (<1%)
Category A/B
Category C
NRTI
Antiretroviral, NRTI