Comparative Pharmacology
Head-to-head clinical analysis: DILANTIN 30 versus EXTENDED PHENYTOIN SODIUM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DILANTIN 30 versus EXTENDED PHENYTOIN SODIUM.
DILANTIN-30 vs EXTENDED PHENYTOIN SODIUM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Stabilizes neuronal membranes by promoting sodium channel inactivation, thereby inhibiting repetitive firing of action potentials.
Phenytoin stabilizes neuronal membranes by promoting sodium channel inactivation, reducing repetitive firing of action potentials, and decreasing synaptic transmission.
300 mg/day orally in 3 divided doses (100 mg three times daily) or 300 mg/day once daily as an extended-release capsule. Loading dose: 1 g orally divided into three doses (400 mg, 300 mg, 300 mg) given at 2-hour intervals. Intravenous fosphenytoin loading dose: 15-20 mg PE/kg; maintenance: 4-6 mg PE/kg/day IV.
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 averages 22 hours (range 7–42 hours) in adults; dose-dependent due to saturable metabolism (Michaelis-Menten kinetics). At low concentrations, half-life is approximately 10–15 hours; at high concentrations, half-life may exceed 30 hours. Clinical context: steady state achieved in 5–10 days; half-life prolonged in neonates, elderly, and hepatic impairment.
22–32 hours (mean 24 hours) in adults, dose-dependent due to saturable metabolism; may exceed 60 hours at high concentrations.
Renal: ~70% (primarily as inactive metabolites including p-HPPH glucuronide, with <5% unchanged); Biliary/fecal: ~30% (enterohepatic circulation contributes to biliary excretion of metabolites and a small amount of unchanged drug).
Primarily hepatic metabolism (CYP2C9/CYP2C19), with <5% excreted unchanged renally. Fecal excretion accounts for minor elimination.
Category C
Category D/X
Anticonvulsant
Anticonvulsant