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What the FDA labels say about taking them together

Carbamazepine and olanzapine

Carbamazepine's FDA label of August 20, 2026 names olanzapine in its drug interactions section, and olanzapine's label names carbamazepine too. The olanzapine label: “Carbamazepine: Increased clearance of olanzapine.”

Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the olanzapine FDA label on DailyMed (effective March 5, 2026, Macleods Pharmaceuticals Limited).

What does the carbamazepine label say about olanzapine?

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

Acetazolamide, aprepitant, azole antifungals (e.g., ketoconazole, itraconazole, fluconazole, voriconazole), cimetidine, ciprofloxacin, clarithromycin, dalfopristin, danazol, dantrolene, delavirdine, diltiazem, erythromycin, fluoxetine, fluvoxamine, grapefruit juice, ibuprofen, isoniazid, loratadine, macrolides, nefazodone, niacinamide, nicotinamide, olanzapine, omeprazole, oxybutynin, protease inhibitors, propoxyphene, quinine, quinupristin, ticlopidine, troleandomycin, valproate, verapamil, zileuton.

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

The following drugs are CYP3A4 inhibitors: Acetazolamide, aprepitant, azole antifungals (e.g., ketoconazole, itraconazole, fluconazole, voriconazole ), cimetidine, ciprofloxacin, clarithromycin, dalfopristin, danazol, dantrolene, delavirdine, diltiazem, erythromycin, fluoxetine, fluvoxamine, grapefruit juice, ibuprofen, isoniazid, loratadine, nefazodone, niacinamide, nicotinamide, olanzapine, omeprazole, oxybutynin, quinine, quinupristin, ticlopidine, troleandomycin, valproate, verapamil, zileuton.

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 olanzapine label say about carbamazepine?

Olanzapine label, drug interactions

Carbamazepine: Increased clearance of olanzapine.

Zyprexa label (H2-Pharma LLC, February 11, 2026), drug interactions

Inducers of CYP1A2 – Carbamazepine therapy (200 mg bid) causes an approximately 50% increase in the clearance of olanzapine.

Source: FDA drug label (Zyprexa, NDA020592), H2-Pharma LLC, effective February 11, 2026 (SPL set b418946a-1ab4-4d89-a012-d94fc361a3c4), via openFDA

Source: FDA drug label (Olanzapine), Macleods Pharmaceuticals Limited, effective March 5, 2026 (SPL set 8e095987-bdea-42f2-9550-c7155cf07d30), 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
43Olanzapine generic labelers
CarbamazepineOlanzapine
Labeled forBipolar disorder, Seizures and epilepsySchizophrenia, Bipolar disorder, Depression
Boxed warningYesYes
Pharmacy cost (NADAC)$0.119 per tablet 200 mg tablet$0.147 per tablet 20 mg tablet
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)

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