Lamotrigine (Lamictal)
Lamotrigine can increase the level of
topiramate in your blood, increasing your risk of side effects. Your healthcare provider may need to decrease your topiramate dose.
Lithium (Eskalith, Lithobid)
Topiramate can decrease the level of
lithium in your blood, perhaps making it less effective. Your healthcare provider may need to monitor the level of lithium in your blood and adjust your
lithium dosage as necessary, especially when starting or stopping topiramate.
Metformin (Fortamet, Glucophage, Glucophage XR, Glumetza, or Riomet)
Topiramate can increase the level of
metformin in your blood, increasing your risk of side effects. Your healthcare provider may need to monitor you more closely and adjust your metformin dose as necessary.
Oral Contraceptives
Studies of a drug interaction between topiramate and
oral contraceptives have shown conflicting results. Some studies have shown no interaction, while others have shown that topiramate may decrease the level of the oral contraceptive in your blood, especially at higher doses. Be sure to discuss this with your healthcare provider. You may need to use a different form of birth control, depending on your topiramate dosage and the particular oral contraceptive.
Phenytoin (Dilantin)
Taking
phenytoin with topiramate can increase the level of phenytoin in your blood and decrease the level of topiramate in your blood. Your healthcare provider may need to adjust your dose of these medications.
Pioglitazone (Actos, Actoplus Met, Duetact)
Topiramate can decrease the level of
pioglitazone in your blood, perhaps making it less effective. Your healthcare provider may need to increase your pioglitazone dose.