What the FDA labels say about taking them together
Carbamazepine and tiagabine
Carbamazepine's FDA label of August 20, 2026 names tiagabine in its drug interactions section, and tiagabine's label names carbamazepine too. The carbamazepine label: “… inhibitors, risperidone, sertraline, sirolimus, tadalafil, theophylline, tiagabine, topiramate, tramadol, trazodone, tricyclic antidepressants, valproate, warfarin, ziprasidone, zonisamide.”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the tiagabine FDA label on DailyMed (effective September 30, 2021, Teva Pharmaceuticals USA, Inc.).
What does the carbamazepine label say about tiagabine?
Carbamazepine label, drug interactions… methsuximide, mianserin, midazolam, olanzapine, oral and other hormonal contraceptives, oxcarbazepine, paliperidone, phensuximide, phenytoin, praziquantel, protease inhibitors, risperidone, sertraline, sirolimus, tadalafil, theophylline, tiagabine, topiramate, tramadol, trazodone, tricyclic antidepressants (e.g., imipramine, amitriptyline, nortriptyline), valproate, warfarin, ziprasidone, zonisamide.
Carbatrol label (Takeda Pharmaceuticals America, Inc., August 17, 2026), drug interactions… nortriptyline, olanzapine, oral and other hormonal contraceptives (2), oxcarbazepine, paliperidone, phenytoin (3), praziquantel, protease inhibitors, quetiapine, risperidone, rivaroxaban (6), sertraline, sirolimus, tadalafil, theophylline, tiagabine, topiramate, tramadol, triazolam, trazodone (4), tricyclic antidepressants (e.g., imipramine, amitriptyline, nortriptyline), valproate, warfarin (5), ziprasidone, and zonisamide. (2) Concomitant use of Carbatrol with hormonal contraceptive products (e.g., oral and levonorgestrel subdermal implant contraceptives) may render the contraceptives less effective because the plasma concentrations of the hormones may be decreased.
Equetro label (Validus Pharmaceuticals LLC, August 19, 2025), drug interactions… mianserin, midazolam, mirtazapine, nefazodone, olanzapine, oral and other hormonal contraceptives, oxcarbazepine, paliperidone, phenytoin, praziquantel, quetiapine, risperidone, sertraline, sirolimus, tadalafil, theophylline, topiramate, tiagabine, tramadol, triazolam, tricyclic antidepressants (e.g., imipramine, amitriptyline, nortriptyline), trazodone, valproate, warfarin, ziprasidone, and zonisamide.
Source: FDA drug label (Carbatrol, NDA020712), Takeda Pharmaceuticals America, Inc., effective August 17, 2026 (SPL set bc03e499-5bac-4293-bff4-6864153a624d), via openFDA
Source: FDA drug label (Equetro, NDA021710), Validus Pharmaceuticals LLC, effective August 19, 2025 (SPL set be478f3c-40f6-47cc-8ab9-f420a9372b1c), via openFDA
Source: FDA drug label (Tegretol), Novartis Pharmaceuticals Corporation, effective August 20, 2026 (SPL set 8d409411-aa9f-4f3a-a52c-fbcb0c3ec053), via openFDA; the full label on DailyMed
What does the tiagabine label say about carbamazepine?
Tiagabine label, drug interactionsCarbamazepine, phenytoin, primidone, and phenobarbital are generally classified as enzyme inducers; valproate and gabapentin are not.
Tiagabine label, warningsThe tiagabine HCl dosing recommendations in current labeling for treatment of epilepsy were based on use in patients with partial seizures 12 years of age and older, most of whom were taking enzyme-inducing antiepileptic drugs (AEDs; e.g., carbamazepine, phenytoin, primidone and phenobarbital) which lower plasma levels of tiagabine HCl by inducing its metabolism.
Source: FDA drug label (Tiagabine Hydrochloride), NDA020646 (Cephalon), as published by Teva Pharmaceuticals USA, Inc., effective September 30, 2021 (SPL set 953ef3cc-e3cb-480f-b9ea-256520fd62b8), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Carbamazepine | Tiagabine | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Seizures and epilepsy |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $2.62 per tablet 2 mg tablet |
| Shortage now | A presentation being discontinued | A presentation being discontinued |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once