What the FDA labels say about taking them together
Carbamazepine and divalproex
Carbamazepine's FDA label of August 20, 2026 names divalproex in its drug interactions section, and divalproex's label names carbamazepine too. The divalproex label: “… drug monotherapy treatments evaluated: lamotrigine (108 [95% CI 105–110]), carbamazepine (105 [95% CI 102–108]), and phenytoin (108 [95% CI 104–112]).”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the divalproex FDA label on DailyMed (effective March 31, 2026, AbbVie Inc.).
What does the carbamazepine label say about divalproex?
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.
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 (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 divalproex label say about carbamazepine?
Divalproex label, drug interactionsDRUG INTERACTIONS Hepatic enzyme-inducing drugs (e.g., phenytoin, carbamazepine, phenobarbital, primidone, rifampin) can increase valproate clearance, while enzyme inhibitors (e.g., felbamate) can decrease valproate clearance.
Divalproex label, warnings and precautionsThe largest of these studies 1 is a prospective cohort study conducted in the United States and United Kingdom that found that children with prenatal exposure to valproate (n=62) had lower IQ scores at age 6 (97 [95% CI 94-101]) than children with prenatal exposure to the other antiepileptic drug monotherapy treatments evaluated: lamotrigine (108 [95% CI 105–110]), carbamazepine (105 [95% CI 102–108]), and phenytoin (108 [95% CI 104–112]).
Source: FDA drug label (Depakote), AbbVie Inc., effective March 31, 2026 (SPL set 08a65cf4-7749-4ceb-6895-8f4805e2b01f), 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 | Divalproex | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Bipolar disorder, Migraine, Seizures and epilepsy |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $0.194 per tablet 500 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