What the FDA labels say about taking them together
Busulfan and metronidazole
Busulfan's FDA label of June 27, 2024 names metronidazole in its drug interactions section, and metronidazole's label names busulfan too. The metronidazole label: “Busulfan Metronidazole has been reported to increase plasma concentrations of busulfan, which can result in an increased risk for serious busulfan toxicity.”
Check it at the source: the busulfan FDA label on DailyMed (effective June 27, 2024, Eugia US LLC); the metronidazole FDA label on DailyMed (effective September 3, 2024, Aurobindo Pharma Limited).
What does the busulfan label say about metronidazole?
Busulfan label, drug interactionsDRUG INTERACTIONS Drugs that Decrease Busulfan Clearance: Metronidazole, itraconazole, iron chelating agents, acetaminophen. ( 7.1 ) Drugs that Increase Busulfan Clearance:
Source: FDA drug label (Busulfan), Eugia US LLC, effective June 27, 2024 (SPL set 06883ac0-4b2a-4f26-89bf-512d37b9ba7f), via openFDA; the full label on DailyMed
What does the metronidazole label say about busulfan?
Metronidazole label, drug interactionsBusulfan Metronidazole has been reported to increase plasma concentrations of busulfan, which can result in an increased risk for serious busulfan toxicity.
Metronidazole label (Baxter Healthcare Corporation, June 12, 2025), drug interactionsBusulfan Metronidazole has been reported to increase plasma concentrations of busulfan, which can result in an increased risk for serious busulfan toxicity such as sinusoidal obstruction syndrome, gastrointestinal mucositis, and hepatic veno-occlusive disease.
Source: FDA drug label (Metronidazole, NDA018657), Baxter Healthcare Corporation, effective June 12, 2025 (SPL set d2112f37-5080-4a19-bcc3-6386b49abe1d), via openFDA
Source: FDA drug label (Metronidazole), Aurobindo Pharma Limited, effective September 3, 2024 (SPL set f68397ee-67db-472e-8607-4300064e37df), 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
| Busulfan | Metronidazole | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | Bacterial infections |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $0.102 per tablet 250 mg tablet |
| Shortage now | A presentation being discontinued | In shortage |
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