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What the FDA labels say about taking them together

Amiodarone and metronidazole

Metronidazole's FDA label (Metronidazole) of June 12, 2025 names amiodarone in its drug interactions section; the amiodarone labels PlainMeds reads (2) do not name metronidazole. The metronidazole label: “Cytochrome P450 3A4 (CYP3A4) substrates Concomitant use of Metronidazole Injection and CYP3A4 substrates may increase respective CYP3A4-substrate plasma levels.”

Check it at the source: the amiodarone FDA label on DailyMed (effective December 9, 2025, Chartwell RX, LLC); the metronidazole FDA label on DailyMed (effective September 3, 2024, Aurobindo Pharma Limited).

What does the amiodarone label say about metronidazole?

Amiodarone's label (effective December 9, 2025) and its 1 other brand-application label do not name metronidazole in these sections. A label lists what its studies and reports found; it is not a complete list.

Source: FDA drug label (Amiodarone Hydrochloride), Chartwell RX, LLC, effective December 9, 2025 (SPL set 5520f11d-968d-4f4f-bf57-d14369c0d746), via openFDA; the full label on DailyMed

What does the metronidazole label say about amiodarone?

Metronidazole label (Baxter Healthcare Corporation, June 12, 2025), drug interactions

Cytochrome P450 3A4 (CYP3A4) substrates Concomitant use of Metronidazole Injection and CYP3A4 substrates (e.g., amiodarone, tacrolimus, cyclosporine, carbamazepine, phenytoin, and quinidine) may increase respective CYP3A4-substrate plasma levels.

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

32Amiodarone generic labelers
55Metronidazole generic labelers
AmiodaroneMetronidazole
Labeled forn/aBacterial infections
Boxed warningYesYes
Pharmacy cost (NADAC)$0.122 per tablet 200 mg tablet$0.102 per tablet 250 mg tablet
Shortage nowNo current entryIn shortage

Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)

What next?