Comparative Pharmacology
Head-to-head clinical analysis: FELBAMATE versus TOPAMAX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FELBAMATE versus TOPAMAX.
FELBAMATE vs TOPAMAX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Felbamate enhances GABAergic transmission and inhibits NMDA receptor activity, likely through interaction with the glycine recognition site.
Antiepileptic; modulates voltage-gated sodium channels, enhances GABA-A activity, antagonizes AMPA/kainate glutamate receptors, weakly inhibits carbonic anhydrase.
1200-3600 mg/day orally in 3-4 divided doses; initiate at 1200 mg/day and titrate by 600-1200 mg/day every 2 weeks.
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
Terminal elimination half-life: 13-23 hours in adults (mean ~20 hours); may be prolonged to 30-40 hours in patients with hepatic impairment or those on enzyme inhibitors; clinical context: requires twice-daily dosing; steady-state reached in 4-5 days
Clinical Note
moderateFelbamate + Estrone sulfate
"The serum concentration of Estrone sulfate can be decreased when it is combined with Felbamate."
Clinical Note
moderateFelbamate + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Felbamate."
Clinical Note
moderateFelbamate + Fluconazole
"The metabolism of Fluconazole can be decreased when combined with Felbamate."
Clinical Note
moderateFelbamate + Clotrimazole
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: approximately 90% (40-50% unchanged, remainder as metabolites including p-hydroxyfelbamate, 2-hydroxyfelbamate, and felbamate monocarbamate); fecal < 5%
Renal: ~70% (unchanged drug); remainder as metabolites. Biliary/fecal: minimal (<5%).
Category C
Category C
Anticonvulsant
Anticonvulsant
"The metabolism of Clotrimazole can be decreased when combined with Felbamate."