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What the FDA labels say about taking them together

Carbamazepine and ethosuximide

Carbamazepine's FDA label of August 20, 2026 names ethosuximide in its drug interactions section; the ethosuximide labels PlainMeds reads (2) do not name carbamazepine. The carbamazepine label: “… calcium channel blockers (e.g., felodipine), doxycycline, eslicarbazepine, ethosuximide, everolimus, haloperidol, imatinib, itraconazole, lamotrigine, levothyroxine, methadone, methsuximide, mianserin, midazolam …”

Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the ethosuximide FDA label on DailyMed (effective June 11, 2026, Chartwell Governmental & Specialty RX, LLC.).

What does the carbamazepine label say about ethosuximide?

Carbamazepine label, drug interactions

In addition, Tegretol causes, or would be expected to cause, decreased levels of the following drugs, for which monitoring of concentrations or dosage adjustment may be necessary: acetaminophen, albendazole, alprazolam, aprepitant, buprenorphone, bupropion, citalopram, clonazepam, clozapine, corticosteroids (e.g., prednisolone, dexamethasone), cyclosporine, dicumarol, dihydropyridine calcium channel blockers (e.g., felodipine), doxycycline, eslicarbazepine, ethosuximide, everolimus, haloperidol, imatinib, itraconazole, lamotrigine, levothyroxine, methadone, methsuximide, mianserin, midazolam, olanzapine, oral and other hormonal contraceptives, oxcarbazepine, paliperidone, phensuximide …

Carbatrol label (Takeda Pharmaceuticals America, Inc., August 17, 2026), drug interactions

Acetaminophen, albendazole, alprazolam, aprepitant, buprenorphine, apixaban (6), bupropion, buspirone, citalopram, clobazam, clonazepam, clozapine, corticosteroids (e.g. prednisolone, dexamethasone), cyclosporin, dabigatran (6), delavirdine, desipramine, diazepam, dicumarol, dihydropyridine calcium channel blockers (e.g., felodipine), doxycycline, edoxaban (6), eslicarbazepine, ethosuximide, everolimus, felbamate, haloperidol, imatinib, itraconazole, lamotrigine, levothyroxine, lorazepam, methadone, methsuximide, midazolam, mirtazapine, nefazodone, nortriptyline, olanzapine, oral and other hormonal contraceptives (2), oxcarbazepine, paliperidone, phenytoin (3), praziquantel, protease …

Equetro label (Validus Pharmaceuticals LLC, August 19, 2025), drug interactions

Drugs metabolized by CYP3A4 or CYP1A2 include the following: Acetaminophen, albendazole, alprazolam, aprepitant, buprenorphone, bupropion, buspirone, citalopram, clobazam, clonazepam, clozapine, cyclosporin, delavirdine, desipramine, diazepam, dicumarol, dihydropyridine calcium channel blockers (e.g., felodipine), doxycycline, ethosuximide, everolimus, felbamate, glucocorticoids, haloperidol, imatinib, itraconazole, lamotrigine, levothyroxine, lorazepam, methadone, methsuxamide, mianserin, midazolam, mirtazapine, nefazodone, olanzapine, oral and other hormonal contraceptives, oxcarbazepine, paliperidone, phenytoin, praziquantel, quetiapine, risperidone, sertraline, sirolimus, tadalafil …

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 ethosuximide label say about carbamazepine?

Ethosuximide's label (effective June 11, 2026) and its 1 other brand-application label do not name carbamazepine in these sections. A label lists what its studies and reports found; it is not a complete list.

Source: FDA drug label (Ethosuximide), Chartwell Governmental & Specialty RX, LLC., effective June 11, 2026 (SPL set a825265d-ace9-4463-a16d-f6d5e1e31188), 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

42Carbamazepine generic labelers
9Ethosuximide generic labelers
CarbamazepineEthosuximide
Labeled forBipolar disorder, Seizures and epilepsySeizures and epilepsy
Boxed warningYesNo
Pharmacy cost (NADAC)$0.119 per tablet 200 mg tablet$0.243 per capsule 250 mg capsule
Shortage nowA presentation being discontinuedNo current entry

Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)

What next?