Comparative Pharmacology
Head-to-head clinical analysis: DIVALPROEX SODIUM versus TOPAMAX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DIVALPROEX SODIUM versus TOPAMAX.
DIVALPROEX SODIUM vs TOPAMAX
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.
Antiepileptic; modulates voltage-gated sodium channels, enhances GABA-A activity, antagonizes AMPA/kainate glutamate receptors, weakly inhibits carbonic anhydrase.
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.
Initial dose 25 mg orally twice daily; titrate by 25-50 mg weekly to effective dose; usual maintenance dose 200-400 mg/day divided twice daily; maximum 1600 mg/day.
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.
Terminal elimination half-life is 21 hours (range 18-23 hours). Linear pharmacokinetics. Half-life is prolonged in renal impairment (CrCl <70 mL/min: ~35 hours).
Renal: <3% unchanged; primarily hepatic metabolism (glucuronidation, beta-oxidation, cytochrome P450), metabolites eliminated renally; fecal: negligible.
Renal: ~70% (unchanged drug); remainder as metabolites. Biliary/fecal: minimal (<5%).
Category D/X
Category C
Anticonvulsant
Anticonvulsant