Drug General Information (ID: DDI3CJ8G9X)
  Drug Name Topiramate Drug Info Ethotoin Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Anticonvulsants Anticonvulsants
  Structure

 Mechanism of Topiramate-Ethotoin Interaction (Severity Level: Moderate)
     Decreased metabolism (Unspecific) Click to Show/Hide Mechanism Graph
      Drug Name Topiramate Ethotoin
      Mechanism Inhibit the hepatic metabolism of hydantoins Hydantoins
      Key Mechanism Factor 1
Factor Name Pharmacokinetics
Factor Description Alters the metabolism of the drug, leading to changes in the plasma concentration of the drug and affecting the pharmacological effects.
      Mechanism Description
  • Decreased metabolism of Ethotoin caused by Topiramate 

Recommended Action
      Management Patients should be closely observed for clinical response and signs of hydantoin toxicity if these drugs must be given concurrently and serum concentrations should be monitored. Patients should be advised to notify their physician if they experience loss of seizure control or symptoms of hydantoin toxicity, including drowsiness, visual disturbances, change in mental status, seizures, nausea, or ataxia. Addition or withdrawal of hydantoins during therapy with topiramate may require a dose adjustment of topiramate and/or the hydantoin.

References
1 Bourgeois BF "Drug interaction profile of topiramate." Epilepsia 37(suppl 2 (1996): s14-7. [PMID: 8641241]
2 Product Information. Topamax (topiramate). Ortho Pharmaceutical Corporation, Raritan, NJ.