Trokendi XR Drug Interactions

Alcohol: Alcohol use is contraindicated within 6 hours prior to and 6 hours after Topiramate (Trokendi XR) administration (see Contraindications and Interaction with Alcohol under Precautions).
Antiepileptic Drugs: Concomitant administration of phenytoin or carbamazepine with topiramate resulted in a clinically significant decrease in plasma concentrations of topiramate when compared to topiramate given alone. A dosage adjustment may be needed (see Dosing in Monotherapy Epilepsy under Dosage & Administration, Pharmacology: Pharmacokinetics under Actions).
Concomitant administration of valproic acid and topiramate has been associated with hypothermia and hyperammonemia with and without encephalopathy. Examine blood ammonia levels in patients in whom the onset of hypothermia has been reported [see Hyperammonemia and Encephalopathy (Without and With Concomitant Valproic Acid Use) and Hypothermia with Concomitant Valproic Acid Use under Precautions and Pharmacology: Pharmacokinetics under Actions].
Other Carbonic Anhydrase Inhibitors: Concomitant use of topiramate, a carbonic anhydrase inhibitor, with any other carbonic anhydrase inhibitor (e.g., zonisamide or acetazolamide) may increase the severity of metabolic acidosis and may also increase the risk of kidney stone formation. Patients should be monitored for the appearance or worsening of metabolic acidosis when Topiramate (Trokendi XR) is given concomitantly with another carbonic anhydrase inhibitor (see Pharmacology: Pharmacokinetics under Actions).
CNS Depressants: Concomitant administration of topiramate with other CNS depressant drugs or alcohol has not been evaluated in clinical studies. Because of the potential of topiramate to cause CNS depression, as well as other cognitive and/or neuropsychiatric adverse reactions, Topiramate (Trokendi XR) should be used with extreme caution if used in combination with alcohol and other CNS depressants (see Contraindications and Cognitive/Neuropsychiatric Adverse Reactions under Precautions).
Oral Contraceptives: The possibility of decreased contraceptive efficacy and increased breakthrough bleeding may occur in patients taking combination oral contraceptive products with Topiramate (Trokendi XR). Patients taking estrogen-containing contraceptives should be asked to report any change in their bleeding patterns. Contraceptive efficacy can be decreased even in the absence of breakthrough bleeding (see Pharmacology: Pharmacokinetics under Actions).
Hydrochlorothiazide (HCTZ): Topiramate C_max and AUC increased when HCTZ was added to immediate-release topiramate. The clinical significance of this change is unknown. The addition of HCTZ to Topiramate (Trokendi XR) may require a decrease in the Topiramate (Trokendi XR) dose (see Pharmacology: Pharmacokinetics under Actions).
Pioglitazone: A decrease in the exposure of pioglitazone and its active metabolites were noted with the concurrent use of pioglitazone and immediate-release topiramate in a clinical trial. The clinical relevance of these observations is unknown; however, when Topiramate (Trokendi XR) is added to pioglitazone therapy or pioglitazone is added to Topiramate (Trokendi XR) therapy, careful attention should be given to the routine monitoring of patients for adequate control of their diabetic disease state (see Pharmacology: Pharmacokinetics under Actions).
Lithium: An increase in systemic exposure of lithium following topiramate doses of up to 600 mg/day can occur. Lithium levels should be monitored when co-administered with high-dose Topiramate (Trokendi XR) (see Pharmacology: Pharmacokinetics under Actions).
Amitriptyline: Some patients may experience a large increase in amitriptyline concentration in the presence of Topiramate (Trokendi XR) and any adjustments in amitriptyline dose should be made according to the patients' clinical response and not on the basis of plasma levels (see Pharmacology: Pharmacokinetics under Actions).