Comparative Pharmacology
Head-to-head clinical analysis: TOPAMAX SPRINKLE versus VIGABATRIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TOPAMAX SPRINKLE versus VIGABATRIN.
TOPAMAX SPRINKLE vs VIGABATRIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Topiramate is a sulfamate-substituted monosaccharide that blocks voltage-gated sodium channels, enhances GABA-A receptor activity, antagonizes AMPA/kainate glutamate receptors, and inhibits carbonic anhydrase (isoenzymes II and IV).
Irreversibly inhibits GABA transaminase, increasing brain GABA levels.
Initial dose: 25-50 mg orally once daily at bedtime for 1 week; then increase by 25-50 mg/day at weekly intervals to recommended maintenance dose of 200-400 mg/day in 2 divided doses.
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
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
Terminal elimination half-life is approximately 21 hours in adults with normal renal function. This allows for twice-daily dosing. Half-life increases significantly in renal impairment (e.g., 36-46 hours in moderate to severe impairment).
5-8 hours in young adults; 12-17 hours in elderly; prolonged with renal impairment.
Approximately 70% of a dose is excreted unchanged in the urine; the remainder is metabolized and eliminated via renal and biliary routes. Renal elimination of both parent drug and metabolites accounts for ~80%, with minimal fecal excretion.
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."