Comparative Pharmacology
Head-to-head clinical analysis: FAMVIR versus GANCICLOVIR SODIUM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FAMVIR versus GANCICLOVIR SODIUM.
FAMVIR vs GANCICLOVIR SODIUM
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.
Ganciclovir is a synthetic guanine derivative that inhibits viral DNA synthesis. It is phosphorylated to ganciclovir triphosphate by viral thymidine kinase (CMV UL97 gene product) and cellular kinases. Ganciclovir triphosphate competitively inhibits viral DNA polymerase (CMV UL54 gene product) and incorporates into viral DNA, causing chain termination.
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.
5 mg/kg IV every 12 hours for 14-21 days for induction; 5 mg/kg IV once daily or 6 mg/kg IV once daily 5 days per week for maintenance. Oral ganciclovir not available as sodium salt.
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 half-life: 2.5-3.6 hours in normal renal function; prolonged in renal impairment (up to 30 hours in severe cases). Dosage adjustment required for CrCl <80 mL/min.
Renal: 60–70% as penciclovir via tubular secretion and glomerular filtration; fecal: <10%; biliary: <1%.
Renal: >90% unchanged drug via glomerular filtration and tubular secretion. Biliary/fecal: <1%.
Category C
Category D/X
Antiviral
Antiviral