Comparative Pharmacology
Head-to-head clinical analysis: ENTECAVIR versus VIDEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENTECAVIR versus VIDEX.
ENTECAVIR vs VIDEX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Entecavir is a guanosine nucleoside analogue with activity against hepatitis B virus (HBV) polymerase. It is phosphorylated intracellularly to the active triphosphate form, which competes with the natural substrate deoxyguanosine triphosphate and inhibits HBV polymerase (reverse transcriptase) activity, resulting in inhibition of viral DNA synthesis.
Didanosine, a synthetic purine nucleoside analogue of deoxyadenosine, is phosphorylated to active metabolite dideoxyadenosine triphosphate (ddATP), which inhibits HIV-1 reverse transcriptase by competing with natural substrate dATP and causing chain termination after incorporation into viral DNA.
0.5 mg orally once daily; for lamivudine-refractory or decompensated liver disease: 1 mg orally once daily.
Adults: 200 mg orally twice daily (two 100 mg chewable tablets per dose) or 250 mg orally twice daily (two 125 mg buffered powder packets per dose); administer on an empty stomach (at least 30 minutes before or 2 hours after a meal).
None Documented
None Documented
Clinical Note
moderateEntecavir + Ribavirin
"Entecavir may increase the hepatotoxic activities of Ribavirin."
Clinical Note
moderateGanciclovir + Entecavir
"The risk or severity of adverse effects can be increased when Ganciclovir is combined with Entecavir."
Clinical Note
moderateValganciclovir + Entecavir
"The risk or severity of adverse effects can be increased when Valganciclovir is combined with Entecavir."
Terminal elimination half-life is approximately 128-149 hours (5-6 days) in patients with normal renal function; prolonged in renal impairment (up to 40 hours in severe impairment), necessitating dose adjustment based on creatinine clearance.
Terminal elimination half-life: 1.5-2 hours (intravenous), prolonged to 4-8 hours in renal impairment. Clinical context: Requires dose adjustment in CrCl <50 mL/min.
Renal excretion of unchanged drug accounts for 60-73% of the dose; biliary/fecal elimination accounts for 27-40% via active tubular secretion and glomerular filtration.
Renal elimination: approximately 50-60% of dose excreted unchanged in urine via glomerular filtration and active tubular secretion. Fecal elimination: <20% as unchanged drug or metabolites.
Category A/B
Category C
Nucleoside Reverse Transcriptase Inhibitor
Nucleoside Reverse Transcriptase Inhibitor