What the FDA labels say about taking them together
Carmustine and cimetidine
Carmustine's FDA label of April 9, 2026 names cimetidine in its drug interactions section; the cimetidine label PlainMeds reads does not name carmustine. The carmustine label: “DRUG INTERACTIONS Cimetidine: Increased myelosuppression with concomitant use. Phenobarbital: Induces carmustine metabolism, reducing exposure.”
Check it at the source: the carmustine FDA label on DailyMed (effective April 9, 2026, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.); the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.).
What does the carmustine label say about cimetidine?
Carmustine label, drug interactionsDRUG INTERACTIONS Cimetidine: Increased myelosuppression with concomitant use. (7.1) Phenobarbital: Induces carmustine metabolism, reducing exposure.
Carmustine label, warnings and precautionsGreater myelotoxicity (e.g., leukopenia and neutropenia) has been reported when carmustine was combined with cimetidine [see Drug Interactions (7) ].
Source: FDA drug label (CARMUSTINE), Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective April 9, 2026 (SPL set b9b47082-32ee-4abb-a7b2-52292894d3f8), via openFDA; the full label on DailyMed
What does the cimetidine label say about carmustine?
Cimetidine's label (effective July 15, 2026) does not name carmustine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Cimetidine), Mylan Pharmaceuticals Inc., effective July 15, 2026 (SPL set 06c0a509-026f-44e0-9975-a94a8de51d43), 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
| Carmustine | Cimetidine | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | Acid reflux and ulcers |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $0.236 per tablet 300 mg tablet |
| Shortage now | No current entry | 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