Comparative Pharmacology
Head-to-head clinical analysis: DILANTIN versus QUDEXY XR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DILANTIN versus QUDEXY XR.
DILANTIN vs QUDEXY XR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Phenytoin 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 acts by blocking voltage-dependent sodium channels, thereby inhibiting the spread of seizure activity.
Stabilizes neuronal membranes and inhibits repetitive firing of action potentials via blockade of voltage-gated sodium channels; also enhances GABAergic activity and inhibits glutamate release.
300–400 mg/day orally in 2–3 divided doses; IV loading dose 15–20 mg/kg at max 50 mg/min, then 300 mg/day IV divided 2–3 times daily.
Initial dose 25 mg orally twice daily; titrate by 25-50 mg/day every 1-2 weeks to target dose of 200-400 mg/day in two divided doses. Maximum 400 mg/day.
None Documented
None Documented
Average 22 hours (range 7-42 hours) in adults. Dose-dependent; increases with higher concentrations due to saturable metabolism. In neonates: 10-15 hours. In chronic use, half-life may increase.
Terminal elimination half-life is approximately 70-90 hours after multiple dosing, supporting twice-daily dosing; requires slow titration to steady state (2-3 weeks).
Primarily hepatic metabolism to inactive metabolites (p-hydroxyphenyltoin and glucuronide conjugate). Less than 5% excreted unchanged in urine. Fecal excretion minimal (<2%).
Renal: approximately 70% as unchanged drug; fecal: approximately 20%; biliary: minor (<5%).
Category C
Category C
Anticonvulsant
Anticonvulsant