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Drug interactions between Antabuse and Flagyl

Results for the following 2 drugs:
Antabuse (disulfiram)
Flagyl (metronidazole)

Interactions between your drugs


metronidazole ↔ disulfiram

Applies to:Flagyl (metronidazole) and Antabuse (disulfiram)

Consumer information for this interaction is not currently available.

CONTRAINDICATED: Use of a nitroimidazole in patients treated with disulfiram may result in psychotic reactions. The exact mechanism of interaction is unknown, but may involve additive effects on aldehyde dehydrogenase (ALDH) inhibition. The interaction has been reported with metronidazole. In one study, 6 of 29 hospitalized alcoholic patients who were treated with disulfiram (500 mg daily for one month, then 250 mg daily) and metronidazole (750 mg daily for one month, then 250 mg daily) developed acute psychoses or a confusional state, compared to none of the 29 patients receiving disulfiram alone. Five had paranoid delusions and three had visual and auditory hallucinations. Symptoms initially increased following withdrawal of the medications, but resolved slowly over two weeks and did not recur when disulfiram alone was restarted. No data are available for other nitroimidazoles or vaginally administered metronidazole.

MANAGEMENT: Nitroimidazole therapy should not be administered with disulfiram. Metronidazole and benznidazole are specifically contraindicated in patients who have taken disulfiram within the last two weeks according to their product labeling.


  1. "Product Information. Metrogel-Vaginal (metronidazole)." Curatek Pharmaceuticals Ltd, Elk Grove Village, IL.
  2. Knee ST, Razani J "Acute organic brain syndrome: a complication of disulfiram therapy." Am J Psychiatry 131 (1974): 1281-2
  3. Scher JM "Psychotic reaction to disulfiram." JAMA 201 (1967): 175
View all 6 references

Drug Interaction Classification

The classifications below are a guideline only. The relevance of a particular drug interaction to a specific patient is difficult to determine using this tool alone given the large number of variables that may apply.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No information available.

Do not stop taking any medications without consulting your healthcare provider.

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