Comparative Pharmacology
Head-to-head clinical analysis: FAMCICLOVIR versus ZIRGAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FAMCICLOVIR versus ZIRGAN.
FAMCICLOVIR vs ZIRGAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Famciclovir is a prodrug of penciclovir, which inhibits viral DNA polymerase by competing with deoxyguanosine triphosphate, thus inhibiting viral DNA replication. It has activity against herpes simplex virus (HSV-1, HSV-2), varicella-zoster virus (VZV), and Epstein-Barr virus (EBV).
Ganciclovir is a synthetic guanine derivative that inhibits cytomegalovirus (CMV) replication by competitively inhibiting viral DNA polymerase (UL54) and by incorporating into viral DNA, causing chain termination. Ganciclovir is phosphorylated to ganciclovir triphosphate by viral thymidine kinase (UL97) in CMV-infected cells.
500 mg orally three times daily for 7 days for herpes zoster; 125 mg twice daily for 5 days for recurrent genital herpes; 250 mg three times daily for 7 days for first-episode genital herpes; 500 mg twice daily for 7 days for recurrent herpes labialis.
Instill 1 drop (approximately 0.05 mL) into affected eye(s) 5 times daily (approximately every 3 hours while awake) until corneal ulcer heals, then reduce to 1 drop 3 times daily for 7 days.
None Documented
None Documented
Clinical Note
moderateFamciclovir + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Famciclovir."
Clinical Note
moderateFamciclovir + Erythromycin
"The metabolism of Erythromycin can be decreased when combined with Famciclovir."
Clinical Note
moderateFamciclovir + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Famciclovir."
Clinical Note
moderateFamciclovir + Fluconazole
Terminal half-life of penciclovir is 2-3 hours in healthy adults, prolonged to 3-6 hours in hepatic impairment and >20 hours in severe renal impairment (CrCl <30 mL/min), requiring dose adjustment.
Terminal elimination half-life in patients with normal renal function is approximately 3-4 hours; in renal impairment, half-life may be prolonged up to 30 hours, requiring dose adjustment.
Renal elimination: ~60% as penciclovir (active metabolite) and <10% as unchanged famciclovir; biliary/fecal: <5%; the remainder is metabolized to inactive compounds.
Primarily renal excretion as unchanged drug via glomerular filtration and tubular secretion; >90% of a systemically absorbed dose is recovered unchanged in urine.
Category A/B
Category C
Antiviral
Antiviral
"The metabolism of Fluconazole can be decreased when combined with Famciclovir."