Metronidazole and disulfiram-like reactions.

Q: Metronidazole should be avoided with alcohol intake as it may cause disulfiram-like reactions.

A) True

B) False

Answer: B

Although it was once believed that metronidazole could cause disulfiram-like reactions with ETOH, this was based on a few weak reports. Evidence failed to prove any such association. The United States Centers for Disease Control and Prevention (CDC) Sexually Transmitted Infection Guidelines in 2021 removed abstaining from alcohol while taking metronidazole.

Metronidazole does not inhibit alcohol metabolism in the liver or increase blood acetaldehyde production, the basis for disulfiram-like reactions. It is suggested that metronidazole and ethanol both, independently, increase brain serotonin levels, potentially giving an impression of disulfiram-like reactions.

# pharmacology

References:

1. Visapää JP, Tillonen JS, Kaihovaara PS, Salaspuro MP. Lack of disulfiram-like reaction with metronidazole and ethanol. Ann Pharmacother 2002; 36:971.

2. Tillonen J, Väkeväinen S, Salaspuro V, et al. Metronidazole increases intracolonic but not peripheral blood acetaldehyde in chronic ethanol-treated rats. Alcohol Clin Exp Res 2000; 24:570.

3. Karamanakos PN, Panteli ES, Marselos M. Comment on 'Can Metronidazole Cause a Disulfiram-Like Reaction? A Case-Control Study Propensity Matched By Age, Sex and Ethanol. WMJ 2024; 123:3.

4. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep 2021; 70:1.

5. Feldman R, Jaszczenski R. Can Metronidazole Cause a Disulfiram-Like Reaction? A Case-Control Study Propensity Matched by Age, Sex, and Ethanol Concentration. WMJ 2023; 122:171.