What the FDA labels say about taking them together
Carbamazepine and quetiapine
Carbamazepine's FDA label of August 20, 2026 names quetiapine in its drug interactions section, and quetiapine's label names carbamazepine too. The quetiapine label: “Quetiapine exposure is increased by the prototype CYP3A4 inhibitors and decreased by the prototype CYP3A4 inducers.”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the quetiapine FDA label on DailyMed (effective April 10, 2026, H2-Pharma, LLC).
What does the carbamazepine label say about quetiapine?
Carbamazepine label, drug interactionsAccordingly, the dosage of Tegretol should be adjusted and/or the plasma levels monitored when used concomitantly with loxapine, quetiapine, valproic acid, or brivaracetam.
Equetro label (Validus Pharmaceuticals LLC, August 19, 2025), drug interactionsDrugs that Inhibit Epoxide H ydrolase and CYP3A4 Clarithromycin, erythromycin, loxapine, quetiapine, and valproate also inhibit epoxide hydrolase, resulting in increased levels of the active metabolite carbamazepine-10,11-epoxide [see Clinical Pharmacology ( 12.3 )].
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 quetiapine label say about carbamazepine?
Quetiapine label, drug interactionsQuetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, avasimibe, St. John’s wort etc.).
Seroquel Xr label (H2-Pharma, LLC, April 10, 2026), drug interactionsQuetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype of CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, avasimibe, St. John’s wort etc.).
Source: FDA drug label (Seroquel Xr, NDA022047), H2-Pharma, LLC, effective April 10, 2026 (SPL set ab959a35-d0ba-4f18-8f2e-6619d88b16e3), via openFDA
Source: FDA drug label (SEROQUEL), NDA020639 (Cheplapharm), as published by H2-Pharma, LLC, effective April 10, 2026 (SPL set 8ae62aaf-f8c5-417f-baac-0098369ca322), 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 | Quetiapine | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Schizophrenia, Bipolar disorder, Depression |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $0.127 per tablet 300 mg tablet |
| Shortage now | A presentation being discontinued | No 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?
- Check more medicines together
- up to five at once