Comparative Pharmacology
Head-to-head clinical analysis: FOSCARNET SODIUM versus ZOVIRAX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FOSCARNET SODIUM versus ZOVIRAX.
FOSCARNET SODIUM vs ZOVIRAX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Foscarnet is an organic analog of inorganic pyrophosphate that selectively inhibits the DNA polymerase activity of herpesviruses, including cytomegalovirus (CMV) and herpes simplex virus (HSV), at the pyrophosphate binding site without requiring activation by thymidine kinase. It also inhibits HIV reverse transcriptase.
After intracellular phosphorylation to acyclovir triphosphate, selectively inhibits viral DNA polymerase and incorporates into viral DNA, causing chain termination.
Induction: 60 mg/kg IV every 8 hours for 14–21 days, followed by maintenance: 90–120 mg/kg IV once daily. Infuse at no more than 1 mg/kg/min via central or peripheral line.
Herpes simplex: 200 mg orally 5 times daily for 10 days; or 400 mg orally 3 times daily for 5-10 days. Herpes zoster: 800 mg orally 5 times daily for 7-10 days. IV: 5-10 mg/kg every 8 hours for immunocompromised patients with HSV/VZV.
None Documented
None Documented
Terminal elimination half-life is approximately 48 hours (range 24-88 hours), reflecting prolonged intracellular retention; clinical context necessitates dose adjustment for renal impairment and monitoring of renal function.
Terminal elimination half-life is 2.5-3.3 hours in adults with normal renal function; prolonged to 19.5 hours in anuria (creatinine clearance <10 mL/min).
Primarily excreted unchanged by the kidney via glomerular filtration and tubular secretion; >80% of dose recovered in urine within 24 hours; minimal biliary or fecal excretion (<5%).
Renal excretion of unchanged drug via glomerular filtration and tubular secretion accounts for 76-82% of elimination; fecal excretion is less than 2%.
Category A/B
Category C
Antiviral
Antiviral