Comparative Pharmacology
Head-to-head clinical analysis: SYMMETREL versus ZIRGAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SYMMETREL versus ZIRGAN.
SYMMETREL vs ZIRGAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Inhibits influenza A virus uncoating and viral RNA replication; increases dopamine release and blocks dopamine reuptake in the CNS.
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.
100 mg orally twice daily; may increase to 200 mg orally twice daily if tolerated, usually in divided doses. For Parkinson's disease, 100 mg orally twice daily; for drug-induced extrapyramidal reactions, 100 mg orally twice daily.
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
Terminal half-life: 24-48 hours (young adults); 48-72 hours (elderly); may extend to 7-10 days in severe renal impairment. Clinically, steady-state achieved in 4-7 days.
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.
Primarily renal excretion (90-95% unchanged) via glomerular filtration and tubular secretion; minor fecal (<5%). Dose adjustment required in renal impairment.
Primarily renal excretion as unchanged drug via glomerular filtration and tubular secretion; >90% of a systemically absorbed dose is recovered unchanged in urine.
Category C
Category C
Antiviral and Antiparkinsonian
Antiviral