Comparative Pharmacology
Head-to-head clinical analysis: PHENYTOIN versus VIGADRONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PHENYTOIN versus VIGADRONE.
PHENYTOIN vs VIGADRONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Irreversible inhibitor of GABA transaminase (GABA-T), leading to increased brain concentrations of gamma-aminobutyric acid (GABA).
Oral: 300-400 mg/day in 3-4 divided doses; IV: 15-20 mg/kg loading dose, then 300 mg/day maintenance.
Adults: 500 mg orally twice daily, may increase by 500 mg/day every week; maximum 1500 mg twice daily.
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."
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.
Terminal elimination half-life: 5-7 hours in young adults; 12-15 hours in elderly; therapeutic steady-state achieved within 2-3 days.
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%.
Renal: 70% unchanged; hepatic metabolism: 20% (primarily via CYP4A7, not CYP450); fecal: <5%.
Category D/X
Category C
Anticonvulsant
Anticonvulsant