(FDA approved in bold)

• Partial-onset seizures (adjunctive; adults and pediatric patients age 2–16)
  
• Primary generalized tonic-clonic seizures (adjunctive; adults and pediatric patients age 2–16)
  
• Migraine prophylaxis
  
• Drop attacks associated with Lennox-Gastaut syndrome
  
• Obesity
  
• Bipolar disorder
  
• Binge-eating disorder/bulimia
  
• Cluster headache prophylaxis
  
• Idiopathic intracranial hypertension
  
• Alcohol dependence
  
• Essential tremor

There are multiple mechanisms of action, and it is uncertain which of these give the drug its effectiveness

• Augmentation of the GABA-A receptor
  
• Sodium channel blocker
  
• Carbonic anhydrase inhibitor, isoenzymes II and IV
  
• Glutamate receptor (specifically the AMPA/kainate subtype) antagonist
  
• May work by inhibiting protein kinase activity
  
• Possible serotonin activity on 5-HT2_C receptors

• Seizures – may decrease by 2 weeks
  
• Migraines – may decrease in as little as 2 weeks, but can take up to 3 months on a stable dose to see full effect

• Seizures – goal is the remission of seizures. Continue as long as effective and well-tolerated. Consider tapering slowly, stopping after 2 years without seizures, depending on the type of epilepsy
  
• Migraine – goal is a 50% or greater reduction in migraine frequency or severity. Consider tapering or stopping if headaches remit for more than 6 months or if considering pregnancy

• Increase to highest tolerated dose
  
• Epilepsy: consider changing to another agent, adding a second agent or referral for epilepsy surgery evaluation
  
• Migraine: address other issues, such as medication-overuse, other coexisting medical disorders, such as anxiety, and consider changing to another agent or adding a second agent

• For some patients with epilepsy or migraine, low-dose polytherapy with 2 or more drugs may be better tolerated and more effective than high-dose monotherapy
  
• Epilepsy: keep in mind drug interactions and their effect on levels
  
• Migraine: consider beta-blockers, antidepressants, natural products, other AEDs, and non-medication treatments such as biofeedback to improve headache control

• Mild to moderate decreases in bicarbonate can occur with topiramate, but are uncommon reasons for discontinuation. Routine screening for metabolic acidosis is not recommended