Comparative Pharmacology
Head-to-head clinical analysis: DIVALPROEX SODIUM versus MYSOLINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DIVALPROEX SODIUM versus MYSOLINE.
DIVALPROEX SODIUM vs MYSOLINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Increases brain concentrations of gamma-aminobutyric acid (GABA), blocks voltage-gated sodium channels, and modulates T-type calcium channels.
Primidone is a barbiturate anticonvulsant that acts by enhancing GABA-A receptor activity and possibly by blocking sodium channels.
10-15 mg/kg/day orally in divided doses; increase by 5-10 mg/kg/week; maximum 60 mg/kg/day. Extended-release: 25 mg/kg/day orally; increase by 15 mg/kg/day at weekly intervals; maximum 60 mg/kg/day.
250 mg orally 3 times daily; may increase by 250 mg/day every 3 days; usual maintenance 250 mg 3-4 times daily; maximum daily dose 1500 mg.
None Documented
None Documented
9-16 hours (terminal); shorter in children (6-9 hours) and longer in hepatic disease or elderly; clinical context: twice-daily dosing provides stable trough concentrations.
Primidone: 5-15 hours (mean 10 hours); PEMA: 10-18 hours; Phenobarbital: 50-120 hours. Steady state achieved in 2-4 weeks due to accumulation of phenobarbital.
Renal: <3% unchanged; primarily hepatic metabolism (glucuronidation, beta-oxidation, cytochrome P450), metabolites eliminated renally; fecal: negligible.
Primidone is excreted primarily in urine; approximately 60-80% as unchanged drug and metabolites (PEMA, phenobarbital), with less than 10% in feces.
Category D/X
Category C
Anticonvulsant
Anticonvulsant