What the FDA labels say about taking them together
Lithium and metronidazole
Lithium's FDA label of December 23, 2025 names metronidazole in its drug interactions section, and metronidazole's label names lithium too. The lithium label: “Diuretics, NSAID, renin-angiotensin system antagonists, or metronidazole may increase lithium serum concentrations.”
Check it at the source: the lithium FDA label on DailyMed (effective December 23, 2025, Glenmark Pharmaceuticals Inc., USA); the metronidazole FDA label on DailyMed (effective September 3, 2024, Aurobindo Pharma Limited).
What does the lithium label say about metronidazole?
Lithium label, drug interactionsDiuretics, NSAID, renin-angiotensin system antagonists, or metronidazole may increase lithium serum concentrations.
Source: FDA drug label (Lithium Carbonate), Glenmark Pharmaceuticals Inc., USA, effective December 23, 2025 (SPL set 63b3790f-a9b5-47f4-bae1-ddf8b43c13c1), via openFDA; the full label on DailyMed
What does the metronidazole label say about lithium?
Metronidazole label, drug interactionsLithium In patients stabilized on relatively high doses of lithium, short-term metronidazole therapy has been associated with elevation of serum lithium and, in a few cases, signs of lithium toxicity.
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
| Lithium | Metronidazole | |
|---|---|---|
| Labeled for | Bipolar disorder | Bacterial infections |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.104 per capsule 300 mg capsule | $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