Metronidazole and Lithium Interaction

Drug interaction information between Metronidazole and Lithium.

Metronidazole and Lithium have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Metronidazole and Lithium. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Metronidazole

Nitroimidazole Antibiotic

Drug B

Lithium

Mood Stabilizer

How They Interact

Metronidazole can cause lithium to build up in your body, which may lead to lithium poisoning.

FDA Label Information

Lithium 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. Serum lithium and serum creatinine levels should be obtained several days after beginning metronidazole to detect any increase that may precede clinical symptoms of lithium intoxication.

Frequently Asked Questions

What SPL severity band is on file for Metronidazole + Lithium?

Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Lithium has 90 labeled pairs on file vs Metronidazole's 10. In the minor band specifically: Metronidazole has 9 (also Disulfiram, Cimetidine, Phenytoin, Phenobarbital); Lithium has 65 (also Aripiprazole, Asenapine, Canagliflozin, Candesartan).

What mechanism field is on file for Metronidazole and Lithium?

Metronidazole can cause lithium to build up in your body, which may lead to lithium poisoning.

Lithium carries more major-labeled pairs than Metronidazole

SPL source-record counts only. This page's band is minor · classes on file: Metronidazole (Nitroimidazole Antibiotic); Lithium (Mood Stabilizer).

Lithium has 2 major-labeled pairs vs Metronidazole's 1. This page itself is in the minor band, not the major band.

Metronidazole

1 major · 0 moderate · 9 minor · 10 total

Lithium

2 major · 23 moderate · 65 minor · 90 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.