Comparative Pharmacology
Head-to-head clinical analysis: DEPAKOTE ER versus PHENYTOIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEPAKOTE ER versus PHENYTOIN.
DEPAKOTE ER vs PHENYTOIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Increases GABAergic activity by inhibiting GABA transaminase and succinate semialdehyde dehydrogenase; blocks voltage-gated sodium and T-type calcium channels; reduces glutamate release.
Phenytoin is a hydantoin anticonvulsant that stabilizes neuronal membranes and decreases seizure activity by increasing efflux or decreasing influx of sodium ions across cell membranes in the motor cortex during generation of nerve impulses. It use-dependently blocks voltage-gated sodium channels, prolonging their inactivation phase and reducing high-frequency repetitive firing of action potentials.
500-1000 mg orally once daily; usual maximum dose 60 mg/kg/day.
Oral: 300-400 mg/day in 3-4 divided doses; IV: 15-20 mg/kg loading dose, then 300 mg/day maintenance.
None Documented
None Documented
Clinical Note
moderatePhenytoin + Digoxin
"The metabolism of Digoxin can be increased when combined with Phenytoin."
Clinical Note
moderateFosphenytoin + Digoxin
"The metabolism of Digoxin can be increased when combined with Fosphenytoin."
Clinical Note
moderatePhenytoin + Digitoxin
"The metabolism of Digitoxin can be increased when combined with Phenytoin."
Clinical Note
moderateFosphenytoin + Digitoxin
"The metabolism of Digitoxin can be increased when combined with Fosphenytoin."
Terminal elimination half-life is approximately 20 hours (range 10-60 hours); clinical context: extended-release formulation allows once-daily dosing, steady-state achieved in 4-5 days
Average terminal half-life 22 hours (range 7–42 hours) in adults; dose-dependent due to saturation of metabolism at therapeutic concentrations (10–20 mg/L). Half-life increases with higher doses.
Primarily renal (30-50% as glucuronide conjugates, <3% as unchanged drug); minor fecal (10-20%)
Primarily hepatic metabolism (>95%); less than 5% excreted unchanged in urine. Renal excretion of metabolites (glucuronides) accounts for ~80% of elimination; biliary/fecal excretion of metabolites ~20%.
Category C
Category D/X
Anticonvulsant
Anticonvulsant