What the FDA labels say about taking them together
Carbamazepine and cyclophosphamide
Carbamazepine's FDA label of August 20, 2026 names cyclophosphamide in its drug interactions section; the cyclophosphamide labels PlainMeds reads (4) do not name carbamazepine. The carbamazepine label: “The rate of metabolism and the leukopenic activity of cyclophosphamide are reportedly increased by chronic coadministration of CYP3A4 inducers.”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the cyclophosphamide FDA label on DailyMed (effective January 19, 2026, Amneal Pharmaceuticals LLC).
What does the carbamazepine label say about cyclophosphamide?
Carbamazepine label, drug interactionsThe rate of metabolism and the leukopenic activity of cyclophosphamide are reportedly increased by chronic coadministration of CYP3A4 inducers.
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 cyclophosphamide label say about carbamazepine?
Cyclophosphamide's label (effective January 19, 2026) and its 3 other brand-application labels 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 (Cyclophosphamide), Amneal Pharmaceuticals LLC, effective January 19, 2026 (SPL set 520bfe39-dfd5-4a20-9a37-80078afded0d), 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 | Cyclophosphamide | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Leukemia, lymphoma and myeloma |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $1.67 per capsule 50 mg capsule |
| 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