Comparative Pharmacology
Head-to-head clinical analysis: EXTENDED PHENYTOIN SODIUM versus TEGRETOL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EXTENDED PHENYTOIN SODIUM versus TEGRETOL.
EXTENDED PHENYTOIN SODIUM vs TEGRETOL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Phenytoin stabilizes neuronal membranes by promoting sodium channel inactivation, reducing repetitive firing of action potentials, and decreasing synaptic transmission.
Voltage-gated sodium channel blocker; stabilizes neuronal membranes and inhibits repetitive firing. Also inhibits glutamate release and enhances GABA activity.
Oral: 100 mg three times daily; intravenous: 10-20 mg/kg loading dose at a maximum rate of 50 mg/min, then 100 mg every 6-8 hours maintenance.
Initial: 200 mg orally twice daily; increase by 200 mg/day at weekly intervals. Maintenance: 800-1200 mg/day in 2-4 divided doses. Maximum dose: 1600 mg/day. Extended-release: 200-400 mg twice daily.
None Documented
None Documented
22–32 hours (mean 24 hours) in adults, dose-dependent due to saturable metabolism; may exceed 60 hours at high concentrations.
Single dose: 25–65 hours (mean ~35 h); chronic therapy: 12–17 hours due to autoinduction; clinical context: requires 3–4 weeks to reach steady-state after dose adjustment.
Primarily hepatic metabolism (CYP2C9/CYP2C19), with <5% excreted unchanged renally. Fecal excretion accounts for minor elimination.
Primarily hepatic metabolism; ~72% excreted in urine (as metabolites, <2% unchanged), ~28% excreted in feces via bile.
Category D/X
Category C
Anticonvulsant
Anticonvulsant