What the FDA labels say about taking them together
Benznidazole and metronidazole
Benznidazole's FDA label of August 27, 2026 names metronidazole in its contraindications section; the metronidazole labels PlainMeds reads (4) do not name benznidazole.
Check it at the source: the benznidazole FDA label on DailyMed (effective August 27, 2026, Exeltis USA, Inc.); the metronidazole FDA label on DailyMed (effective September 3, 2024, Aurobindo Pharma Limited).
What does the benznidazole label say about metronidazole?
Benznidazole label, contraindicationsSevere irreversible hepatotoxicity/acute liver failure with fatal outcomes have been reported after initiation of metronidazole, another nitroimidazole drug, structurally related to benznidazole in patients with Cockayne syndrome [see Adverse Reactions ( 6.2 )].
Source: FDA drug label (Benznidazole), NDA209570 (Chemo Research Sl), as published by Exeltis USA, Inc., effective August 27, 2026 (SPL set 8983d6a0-f63f-4f8e-bba4-38223f39e29b), via openFDA; the full label on DailyMed
What does the metronidazole label say about benznidazole?
Metronidazole's label (effective September 3, 2024) and its 3 other brand-application labels do not name benznidazole in these sections. A label lists what its studies and reports found; it is not a complete list.
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
| Benznidazole | Metronidazole | |
|---|---|---|
| Labeled for | n/a | Bacterial infections |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | $0.102 per tablet 250 mg tablet |
| Shortage now | No current entry | 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