What the FDA labels say about taking them together
Procarbazine and verapamil
Verapamil's FDA label (Verapamil Hydrochloride) of November 27, 2024 names procarbazine in its drug interactions section; the procarbazine label PlainMeds reads does not name verapamil. The verapamil label: “The absorption of verapamil can be reduced by the cyclophosphamide, oncovin, procarbazine, prednisone (COPP) and the vindesine, adriamycin, cisplatin (VAC) cytotoxic drug regimens.”
Check it at the source: the procarbazine FDA label on DailyMed (effective September 16, 2024, Leadiant Biosciences, Inc.); the verapamil FDA label on DailyMed (effective April 6, 2026, Zydus Pharmaceuticals (USA) Inc.).
What does the procarbazine label say about verapamil?
Procarbazine's label (effective September 16, 2024) does not name verapamil in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Matulane), Leadiant Biosciences, Inc., effective September 16, 2024 (SPL set 1aa75a3a-18c9-49e1-91a6-293d0b7da756), via openFDA; the full label on DailyMed
What does the verapamil label say about procarbazine?
Verapamil Hydrochloride label (Wilshire Pharmaceuticals, Inc., November 27, 2024), drug interactionsThe absorption of verapamil can be reduced by the cyclophosphamide, oncovin, procarbazine, prednisone (COPP) and the vindesine, adriamycin, cisplatin (VAC) cytotoxic drug regimens.
Source: FDA drug label (Verapamil Hydrochloride, NDA020943), Wilshire Pharmaceuticals, Inc., effective November 27, 2024 (SPL set 5f665d08-e1e4-422a-88c2-d8834abf9e1a), via openFDA
Source: FDA drug label (Verapamil hydrochloride), Zydus Pharmaceuticals (USA) Inc., effective April 6, 2026 (SPL set e19ab8d8-dae5-489d-9805-7e7407bea06d), 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
| Procarbazine | Verapamil | |
|---|---|---|
| Labeled for | n/a | High blood pressure, Atrial fibrillation, Angina |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $0.191 per tablet 180 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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