Comparative Pharmacology
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
EFAVIRENZ, EMTRICITABINE, AND TENOFOVIR DISOPROXIL FUMARATE 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 reversibly to HIV-1 reverse transcriptase, causing a conformational change and inhibiting RNA-directed DNA polymerase activity. Emtricitabine and tenofovir disoproxil fumarate are nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) that compete with natural substrates and incorporate into viral DNA, causing 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 (efavirenz 600 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) 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); autoinduction reduces t1/2. Emtricitabine: ~10 h (healthy), extended to 18-24 h in renal impairment. Tenofovir: ~17 h (healthy), >40 h in renal impairment.
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 metabolites), <1% unchanged; 16-61% fecal. Emtricitabine: ~86% renal (65-70% unchanged), 14% fecal. Tenofovir: 70-80% renal (20-30% unchanged via glomerular filtration and active tubular secretion), 20% fecal.
Renal excretion of unchanged drug (~86%) by glomerular filtration and active tubular secretion; fecal excretion (<1%)
Category A/B
Category C
NRTI
Antiretroviral, NRTI