Disulfiram and Metronidazole Interaction

Drug interaction information between Disulfiram and Metronidazole.

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

FDA drug labeling documents a minor-severity interaction between Disulfiram and Metronidazole. 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

Disulfiram

Aldehyde Dehydrogenase Inhibitor

Drug B

Metronidazole

Nitroimidazole Antibiotic

How They Interact

Combining these two medicines can cause serious mental health problems, such as confusion or psychotic reactions.

FDA Label Information

Drug Interactions Disulfiram Psychotic reactions have been reported in alcoholic patients who are using metronidazole and disulfiram concurrently. Metronidazole should not be given to patients who have taken disulfiram within the last two weeks (see CONTRAINDICATIONS ).

Frequently Asked Questions

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

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?

Metronidazole has 10 labeled pairs on file vs Disulfiram's 8. In the minor band specifically: Disulfiram has 7 (also Acamprosate, Amitriptyline, Nabilone, Naltrexone); Metronidazole has 9 (also Lithium, Cimetidine, Phenytoin, Phenobarbital).

What mechanism field is on file for Disulfiram and Metronidazole?

Combining these two medicines can cause serious mental health problems, such as confusion or psychotic reactions.

Metronidazole carries more major-labeled pairs than Disulfiram

SPL source-record counts only. This page's band is minor · classes on file: Disulfiram (Aldehyde Dehydrogenase Inhibitor); Metronidazole (Nitroimidazole Antibiotic).

Metronidazole has 1 major-labeled pair vs Disulfiram's 0. This page itself is in the minor band, not the major band.

Disulfiram

0 major · 1 moderate · 7 minor · 8 total

Metronidazole

1 major · 0 moderate · 9 minor · 10 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.