Metronidazole disulfiram-like reaction with

Visapaa J-P, Tillonen JS, Kaihovaara PS, Salaspuro MP. Lack of disulfiram-like reaction with metronidazole and ethanol. Ann Pharmacolher (2002) 36, 971-4. 

Oral bioavailability is almost 100%. Metronidazole is protein bound for less than 20% and is widely distributed, including the CNS. It is metabolized in the liver with an elimination half-life of 8 hours. Common adverse effects include nausea, headache and taste disturbances. With alcohol a severe disulfiram-like reaction, with flushing, sweating and abdominal cramps will occur. 

Toxicity Adverse effects include gastrointestinal irritation, headache, and dark coloration of urine. More serious toxicity includes leukopenia, dizziness, and ataxia. Drag interactions with metronidazole include a disulfiram-like reaction with ethanol and potentiation of coumarin anticoagulant effects. Although it is not contraindicated in pregnancy, the drug should be used with caution. 

Metronidazole is an antiprotozoal agent that, if taken concomitantly with alcohol, may result in a disulfiram-like reaction characterised by intense vasodilation, headache, tachycardia, sweating and vomiting. 

Oxidation of acetaldehyde is inhibited by disulfiram, a drug that has been used to deter drinking by alcohol-dependent patients undergoing treatment. When ethanol is consumed in the presence of disulfiram, acetaldehyde accumulates and causes an unpleasant reaction of facial flushing, nausea, vomiting, dizziness, and headache. Several other drugs (eg, metronidazole, cefotetan, trimethoprim) inhibit ALDH and can cause a disulfiram-like reaction if combined with ethanol. 

METRONIDAZOLE PROTEASE INHIBITORS t adverse effects, e.g. disulfiram-like reaction, flushing, with ritonavir (with or without lopinavir) Ritonavir and lopinavir oral solutions contain alcohol Warn patient and give alternative preparation if possible... 

A disulfiram-like reaction has occurred when some patients taking oral metronidazole have drunk alcohol. There is one report of its occurrence when metronidazole was applied as a vaginal insert, and another when metronidazole was given intravenously. Some clinical studies have not confirmed the interaction, and its existence is disputed in some reports. The interaction is alleged to occur with all other 5-nitroimidazoles (e.g. tinidazole). 

Edwards DL, Fink PC, Van Dyke PO, Disulfiram-like reaction associated with intravenous trimethoprim-sulfamethoxazole and metronidazole. ClinPharm (1986) 5, 999-1000. 

The UK manufacturer of the oral solution of ritonavir (Norvir) says that since it contains alcohol 43% v/v (which they say is about equivalent to 27 mL of wine per dose) the preparation should not be taken with disulfiram or other drugs such as metronidazole because a disulfiram-like reaction is possible. However, in practice the risk is probably fairly small because the recommended dose of ritonavir in this form is only 7.5 mL. Ritonavir (Norvir) soft capsules also contain alcohol 12% w/w. The... 

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