Review on Topiramate in the Treatment of Epil...

Review on Topiramate in the Treatment of Epilepsy

Author Name : Madhavi Pawar, Samarth Kajale, Srushti Kadam

ABSTRACT To treat epilepsy, Topiramate, an antiepileptic drug, has been available as an IR formulation since 1996. Based on in vitro investigations, several mechanisms have been proposed, including voltage-sensitive sodium channel blockade, GABAA-mediated chloride current increment, glutamate-mediated neurotransmission inhibition, increase in potassium conductance, inhibition of carbonic anhydrase isoenzyme, and interaction with protein kinase phosphorylation sites. Following an oral 400 mg dosage, topiramate is readily absorbed; peak plasma concentrations occur approximately two hours later. Because topiramate has a low metabolism, around 70% of a given dosage is eliminated unchanged in the urine. Compared to immediate-release formulations, extendedrelease formulations have more consistent blood levels of the medication over time; they also have a longer duration of action, which permits less frequent dosing intervals; slower absorption, which results in a delayed onset of action but a more sustained therapeutic effect; and they lower the risk of side effects associated with high peak concentrations while maintaining therapeutic efficacy. These are some of the main differences in the pharmacokinetic profiles of extended-release and immediate-release formulations. Therefore, it is necessary to formulate extended-release tablet with the combination of immediate release topiramate tablet.