What the FDA labels say about taking them together
Carbamazepine and hydrochlorothiazide/irbesartan
Hydrochlorothiazide/irbesartan's FDA label of October 7, 2025 names carbamazepine in its drug interactions section; the carbamazepine labels PlainMeds reads (3) do not name hydrochlorothiazide/irbesartan. The hydrochlorothiazide/irbesartan label: “Increases in serum lithium concentrations and lithium toxicity. Carbamazepine: Increased risk of hyponatremia.”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the hydrochlorothiazide/irbesartan FDA label on DailyMed (effective October 7, 2025, Sanofi-Aventis U.S. LLC).
What does the carbamazepine label say about hydrochlorothiazide/irbesartan?
Carbamazepine's label (effective August 20, 2026) and its 2 other brand-application labels do not name hydrochlorothiazide/irbesartan in these sections. A label lists what its studies and reports found; it is not a complete list.
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 hydrochlorothiazide/irbesartan label say about carbamazepine?
Hydrochlorothiazide/irbesartan label, drug interactionsIncreases in serum lithium concentrations and lithium toxicity. ( 7 ) Carbamazepine: Increased risk of hyponatremia.
Source: FDA drug label (Avalide), Sanofi-Aventis U.S. LLC, effective October 7, 2025 (SPL set 0d91895e-c869-4b33-9b83-d55c1ad6317e), 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 | Hydrochlorothiazide/irbesartan | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | High blood pressure |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $0.149 per tablet 150-12.5 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