Comparative Pharmacology
Head-to-head clinical analysis: TOPAMAX versus VIGABATRIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TOPAMAX versus VIGABATRIN.
TOPAMAX vs VIGABATRIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antiepileptic; modulates voltage-gated sodium channels, enhances GABA-A activity, antagonizes AMPA/kainate glutamate receptors, weakly inhibits carbonic anhydrase.
Irreversibly inhibits GABA transaminase, increasing brain GABA levels.
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.
Adults: 500 mg orally twice daily; may increase by 500 mg/day every 7 days up to 1500 mg twice daily. For refractory complex partial seizures, maximum 3000 mg/day.
None Documented
None Documented
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).
Clinical Note
moderateVigabatrin + Venlafaxine
"The risk or severity of adverse effects can be increased when Vigabatrin is combined with Venlafaxine."
Clinical Note
moderateVigabatrin + Nefazodone
"The risk or severity of adverse effects can be increased when Vigabatrin is combined with Nefazodone."
Clinical Note
moderateVigabatrin + Stiripentol
"The risk or severity of adverse effects can be increased when Vigabatrin is combined with Stiripentol."
Clinical Note
moderateVigabatrin + Clomipramine
5-8 hours in young adults; 12-17 hours in elderly; prolonged with renal impairment.
Renal: ~70% (unchanged drug); remainder as metabolites. Biliary/fecal: minimal (<5%).
Renal: ~80% unchanged in urine; fecal: <5%.
Category C
Category A/B
Anticonvulsant
Anticonvulsant
"The risk or severity of adverse effects can be increased when Vigabatrin is combined with Clomipramine."