Comparative Pharmacology
Head-to-head clinical analysis: DILANTIN versus EQUETRO.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DILANTIN versus EQUETRO.
DILANTIN vs EQUETRO
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.
Equetro (carbamazepine extended-release) is an anticonvulsant and mood stabilizer. It stabilizes the inactivated state of voltage-gated sodium channels, thereby inhibiting repetitive neuronal firing and reducing synaptic transmission. It also potentiates GABA receptors 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: 50 mg orally twice daily; increase by 50-100 mg/day every 2-4 weeks. Usual maintenance: 100-200 mg orally twice daily. Maximum: 200 mg orally twice daily.
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.
Carbamazepine: 25-65 hours (initial single dose), 12-17 hours (chronic dosing due to autoinduction); carbamazepine-10,11-epoxide: 5-8 hours.
Primarily hepatic metabolism to inactive metabolites (p-hydroxyphenyltoin and glucuronide conjugate). Less than 5% excreted unchanged in urine. Fecal excretion minimal (<2%).
Renal: 2% excreted unchanged (carbamazepine) in urine; 15% as carbamazepine-10,11-epoxide; 30% as other metabolites; biliary/fecal: 50-60% as metabolites.
Category C
Category C
Anticonvulsant
Anticonvulsant