Comparative Pharmacology
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE versus EMTRICITABINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE versus EMTRICITABINE.
EFAVIRENZ, EMTRICITABINE, AND TENOFOVIR DISOPROXIL FUMARATE vs EMTRICITABINE
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; phosphorylated to emtricitabine triphosphate which competes with endogenous deoxycytidine triphosphate and incorporates into viral DNA causing 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.
200 mg orally once daily, typically in combination with other antiretroviral agents.
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 is approximately 10 hours (range 8–12 hours) in adults with normal renal function; prolonged to >20 hours in severe renal impairment (CrCl <30 mL/min).
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: approximately 86% of the dose is excreted unchanged in urine via glomerular filtration and active tubular secretion. Biliary/fecal: minimal (<14% as unchanged drug and metabolites in feces).
Category A/B
Category C
NRTI
Antiretroviral, NRTI