Comparative Pharmacology
Head-to-head clinical analysis: GANCICLOVIR SODIUM versus SYMADINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GANCICLOVIR SODIUM versus SYMADINE.
GANCICLOVIR SODIUM vs SYMADINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
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.
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.
100 mg orally every 12 hours; immediate-release formulation.
None Documented
None Documented
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.
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.
Renal: >90% unchanged drug via glomerular filtration and tubular secretion. Biliary/fecal: <1%.
Renal elimination of unchanged drug accounts for approximately 90% of the administered dose. Biliary/fecal excretion is minimal (<5%).
Category D/X
Category C
Antiviral
Antiviral and Antiparkinsonian