Comparative Pharmacology
Head-to-head clinical analysis: FOSCAVIR versus GANCICLOVIR SODIUM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FOSCAVIR versus GANCICLOVIR SODIUM.
FOSCAVIR vs GANCICLOVIR SODIUM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Foscarnet is a pyrophosphate analog that selectively inhibits viral DNA polymerase and reverse transcriptase by binding to the pyrophosphate binding site, preventing the cleavage of pyrophosphate from deoxynucleotide triphosphates, thereby inhibiting viral DNA synthesis. It does not require activation by viral thymidine kinase, making it active against acyclovir-resistant HSV and VZV, and ganciclovir-resistant CMV.
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.
Induction: 60 mg/kg IV every 8 hours for 2-3 weeks, then maintenance: 90-120 mg/kg IV once daily. Administer as a 2-hour infusion via central line.
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 is approximately 3-5 hours in patients with normal renal function; can extend to 48-120 hours in severe renal impairment (CrCl <20 mL/min), requiring dose adjustment and therapeutic drug monitoring.
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.
Primarily renal excretion (>80% as unchanged drug) via glomerular filtration and tubular secretion; minimal biliary/fecal elimination (<5%).
Renal: >90% unchanged drug via glomerular filtration and tubular secretion. Biliary/fecal: <1%.
Category C
Category D/X
Antiviral
Antiviral