Comparative Pharmacology
Head-to-head clinical analysis: FAMVIR versus HEPSERA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FAMVIR versus HEPSERA.
FAMVIR vs HEPSERA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Famciclovir is a prodrug that is rapidly converted to penciclovir, which inhibits viral DNA polymerase by competing with deoxyguanosine triphosphate, thereby inhibiting viral DNA synthesis and replication.
Acyclic nucleotide analog of adenosine monophosphate; inhibits hepatitis B virus (HBV) DNA polymerase by competing with the natural substrate dATP, causing DNA chain termination after incorporation into viral DNA.
250 mg orally three times daily for 7 days for herpes zoster; 125 mg orally twice daily for 5 days for recurrent genital herpes; 250 mg orally twice daily for 7 days for first-episode genital herpes; 500 mg orally twice daily for 7 days for herpes zoster in immunocompromised patients; 500 mg orally twice daily for 7 days for recurrent mucocutaneous herpes in HIV patients.
10 mg orally once daily.
None Documented
None Documented
Terminal elimination half-life of penciclovir is approximately 2–3 hours in patients with normal renal function; extends to 9–18 hours in severe renal impairment (CrCl <30 mL/min).
Terminal elimination half-life is approximately 6-9 hours in patients with normal renal function. In renal impairment, half-life is prolonged (up to 18 hours in moderate impairment, >30 hours in severe impairment). Steady-state is achieved within 5-7 days.
Renal: 60–70% as penciclovir via tubular secretion and glomerular filtration; fecal: <10%; biliary: <1%.
Primarily renal; 70-90% of an oral dose is excreted unchanged in urine via active tubular secretion and glomerular filtration. Biliary/fecal elimination accounts for <5%.
Category C
Category C
Antiviral
Antiviral