Comparative Pharmacology
Head-to-head clinical analysis: CELONTIN versus EXTENDED PHENYTOIN SODIUM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CELONTIN versus EXTENDED PHENYTOIN SODIUM.
CELONTIN vs EXTENDED PHENYTOIN SODIUM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Increases levels of gamma-aminobutyric acid (GABA) in the central nervous system, possibly by inhibiting GABA transaminase or enhancing GABA release; also reduces calcium influx into neurons, stabilizing neuronal membranes.
Phenytoin stabilizes neuronal membranes by promoting sodium channel inactivation, reducing repetitive firing of action potentials, and decreasing synaptic transmission.
300 mg orally three times daily, increased by 300 mg every 3-4 days as tolerated; usual maintenance dose 900-2400 mg/day in divided doses.
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.
None Documented
None Documented
Terminal elimination half-life: 40-60 hours in adults, 30-45 hours in children; prolonged liver disease or renal impairment may increase half-life.
22–32 hours (mean 24 hours) in adults, dose-dependent due to saturable metabolism; may exceed 60 hours at high concentrations.
Renal: approximately 40-60% as unchanged drug; hepatic metabolism accounts for the remainder, with metabolites excreted renally.
Primarily hepatic metabolism (CYP2C9/CYP2C19), with <5% excreted unchanged renally. Fecal excretion accounts for minor elimination.
Category C
Category D/X
Anticonvulsant
Anticonvulsant