Comparative Pharmacology
Head-to-head clinical analysis: FOSCARNET SODIUM versus SYMADINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FOSCARNET SODIUM versus SYMADINE.
FOSCARNET SODIUM vs SYMADINE
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.
SYMADINE (amantadine) is a tricyclic amine that inhibits influenza A virus replication by blocking the viral M2 ion channel, which prevents uncoating of viral RNA. It also increases dopamine release and inhibits dopamine reuptake in the CNS, providing antiparkinsonian effects.
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.
100 mg orally every 12 hours; immediate-release formulation.
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.
The terminal elimination half-life is approximately 24 hours in patients with normal renal function. In patients with renal impairment (CrCl <50 mL/min), the half-life is significantly prolonged, requiring dose adjustment. The long half-life allows for once-daily dosing.
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 elimination of unchanged drug accounts for approximately 90% of the administered dose. Biliary/fecal excretion is minimal (<5%).
Category A/B
Category C
Antiviral
Antiviral and Antiparkinsonian