Comparative Pharmacology
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EFAVIRENZ EMTRICITABINE TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
EFAVIRENZ; EMTRICITABINE; 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-dependent and DNA-dependent DNA polymerase activity. Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) that, after intracellular phosphorylation, competes with deoxycytidine 5'-triphosphate and incorporates into viral DNA, causing chain termination. Tenofovir disoproxil fumarate is an acyclic nucleoside phosphonate diester analog of adenosine monophosphate that, after hydrolysis and phosphorylation, inhibits HIV-1 reverse transcriptase and hepatitis B virus DNA polymerase 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 (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: 40-55 hours (single dose), 52-76 hours (steady state). Emtricitabine: 10 hours (healthy), extended to >20 hours in renal impairment. Tenofovir: 17 hours (healthy), prolonged in renal impairment (up to 7 days with CrCl <30 mL/min).
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% excreted in urine (primarily as metabolites) and ~16-61% in feces. Emtricitabine: ~86% excreted unchanged in urine and ~14% as metabolites. Tenofovir disoproxil fumarate: ~70-80% excreted unchanged in urine via glomerular 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