Comparative Pharmacology
Head-to-head clinical analysis: MYSOLINE versus VALPROIC ACID.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MYSOLINE versus VALPROIC ACID.
MYSOLINE vs VALPROIC ACID
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Primidone is a barbiturate anticonvulsant that acts by enhancing GABA-A receptor activity and possibly by blocking sodium channels.
Increases GABA concentration in the brain by inhibiting GABA transaminase and succinic semialdehyde dehydrogenase; also blocks voltage-gated sodium channels and T-type calcium channels.
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.
Initial: 10-15 mg/kg/day orally (divided 2-3 times), increase by 5-10 mg/kg/week; maintenance: 30-60 mg/kg/day. IV infusion: same oral dose, rate ≤20 mg/min.
None Documented
None Documented
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.
Clinical Note
moderateValproic acid + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Valproic acid is combined with Fluticasone propionate."
Clinical Note
moderateValproic acid + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Valproic acid."
Clinical Note
moderateValproic acid + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Valproic acid."
Clinical Note
moderateValproic acid + Fluconazole
Terminal elimination half-life is 9–16 hours in adults; shorter in children (6–9 hours) and longer in neonates (20–30 hours), elderly, or hepatic impairment (up to 18 hours).
Primidone is excreted primarily in urine; approximately 60-80% as unchanged drug and metabolites (PEMA, phenobarbital), with less than 10% in feces.
Primarily hepatic metabolism (>95%), with less than 3% excreted unchanged in urine. Minor fecal excretion (~5%).
Category C
Category D/X
Anticonvulsant
Anticonvulsant
"The metabolism of Fluconazole can be decreased when combined with Valproic acid."