Comparative Pharmacology
Head-to-head clinical analysis: HERPLEX versus VALACYCLOVIR HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HERPLEX versus VALACYCLOVIR HYDROCHLORIDE.
HERPLEX vs VALACYCLOVIR HYDROCHLORIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Inhibits viral DNA polymerase after phosphorylation to acyclovir triphosphate, leading to chain termination and inhibition of herpes simplex virus replication.
Valacyclovir hydrochloride is a prodrug of acyclovir. After oral administration, it is rapidly converted to acyclovir, which inhibits viral DNA polymerase, leading to chain termination and inhibition of viral DNA replication.
Acyclovir 200 mg orally 5 times daily for 10 days for initial genital herpes; 400 mg orally twice daily for suppressive therapy; 5-10 mg/kg IV every 8 hours for severe infections.
500 mg orally twice daily for recurrent genital herpes; 1 g orally twice daily for herpes zoster; 1 g orally three times daily for herpes simplex encephalitis or immunocompromised patients.
None Documented
None Documented
2.5–3.3 hours in adults with normal renal function; prolonged to 10–20 hours in anuria (CrCl <10 mL/min); requires dose adjustment in renal impairment
Terminal elimination half-life: 2.5–3.3 hours in patients with normal renal function; prolonged to 14 hours in renal impairment (CrCl 15–30 mL/min).
Renal: ~90% as unchanged drug via glomerular filtration and tubular secretion; minor biliary/fecal elimination (<2%)
Renal excretion: >90% as unchanged drug and inactive metabolite (9-carboxymethoxymethylguanine). Biliary/fecal: <2%.
Category C
Category A/B
Antiviral
Antiviral