Comparative Pharmacology
Head-to-head clinical analysis: EFAVIRENZ LAMIVUDINE TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EFAVIRENZ LAMIVUDINE TENOFOVIR DISOPROXIL FUMARATE versus EMTRIVA.
EFAVIRENZ; LAMIVUDINE; 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 to reverse transcriptase and blocks RNA-dependent and DNA-dependent DNA polymerase activities. Lamivudine is a nucleoside reverse transcriptase inhibitor (NRTI) that inhibits HIV reverse transcriptase via DNA chain termination. Tenofovir disoproxil fumarate is a nucleotide reverse transcriptase inhibitor (NtRTI) that competes with natural substrates and causes DNA chain termination after phosphorylation 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 (efavirenz 600 mg, lamivudine 300 mg, tenofovir disoproxil fumarate 300 mg) orally once daily on an empty stomach (preferably at bedtime to reduce CNS side effects).
Emtricitabine 200 mg orally once daily.
None Documented
None Documented
Efavirenz: 40-55 hours (single dose), 52-76 hours (multiple doses); Lamivudine: 5-7 hours; Tenofovir: 12-18 hours (prolonged to 24-30 hours when co-administered with efavirenz).
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% unchanged in urine, 16-61% as metabolites in feces; Lamivudine: ~70% unchanged in urine via glomerular filtration and active tubular secretion; Tenofovir disoproxil fumarate: 70-80% 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