Tiagabine and Zonisamide interaction
Tiagabine and Zonisamide: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Zonisamide (ZONISADE) label · effective 2025-09-08
Patients should be carefully observed for signs of central nervous system (CNS) depression, such as somnolence and sedation, when ZONISADE is used with other drugs with sedative properties because of potential additive effects.
• ZONISADE should be used with caution if used in combination with alcohol or other CNS depressants ( 7.1 ).
From the Tiagabine (Tiagabine Hydrochloride) label · effective 2021-09-30
Effects of other Antiepilepsy Drugs (AEDs) on Tiagabine HCl: Carbamazepine : Population pharmacokinetic analyses indicate that tiagabine clearance is 60% greater in patients taking carbamazepine with or without other enzyme-inducing AEDs.
Phenytoin : Population pharmacokinetic analyses indicate that tiagabine clearance is 60% greater in patients taking phenytoin with or without other enzyme-inducing AEDs.
Phenobarbital (Primidone) : Population pharmacokinetic analyses indicate that tiagabine clearance is 60% greater in patients taking phenobarbital (primidone) with or without other enzyme-inducing AEDs.
Effects of Tiagabine HCl on other Antiepilepsy Drugs (AEDs): Phenytoin : Tiagabine had no effect on the steady-state plasma concentrations of phenytoin in patients with epilepsy.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.