How the interaction occurs:
Metronidazole and tinidazole cause an intolerance to alcohol by altering how the body breaks down alcohol. Many medicines (prescription and nonprescription), mouthwashes, and aftershaves contain alcohol. Even a small amount of alcohol (e.g. 15 ml or one tablespoon) can trigger the effects.
What might happen:
Ingesting alcohol or using topical preparations that contain alcohol may result in throbbing in the head and neck, irregular heart beat, rapid heart beat, low blood pressure, sweating, nausea, and vomiting. This interaction may last from 30 to 60 minutes to several hours, depending on the amount of alcohol consumed.
What you should do about this interaction:
If possible, avoid the use of medicines that contain alcohol when using metronidazole. Use of topical products such as creams or lotions that contain alcohol may also cause this interaction. The amount of alcohol required to cause this interaction varies with individuals.If you are using metronidazole with a product that contains alcohol, or if you notice signs or symptoms of this interaction, contact your healthcare professional (e.g. doctor or pharmacist). Your doctor may want to do blood tests or make changes to your medicines.If you are taking tinidazole, avoid alcoholic beverages and products containing alcohol while you are taking tinidazole and for 3 days after you finish taking tinidazole.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Gupta NK, Woodley CL, Fried R. Effect of metronidazole on liver alcohol dehydrogenase. Biochem Pharmacol 1970 Oct;19(10):2805-8.
2.Kitson TM. The disulfiram--ethanol reaction: a review. J Stud Alcohol 1977 Jan;38(1):96-113.
3.Edwards JA, Price J. Metronidazole and atypical human alcohol dehydrogenase. Biochem Pharmacol 1967 Oct;16(10):2026-7.
4.Fried R, Fried LW. The effect of Flagyl on xanthine oxidase and alcohol dehydrogenase. Biochem Pharmacol 1966;15:1890-94.
5.Paltrinieri E. Inhibitory action of hydroxy-2-ethyl-1-methyl-2-nitro-5-imidazole on alcohol-dehydrogenase. Farmaco Sci 1967 Dec;22(12):1054-6.
6.Tindamax (tinidazole) US prescribing information. Presutti Laboratories, Inc. August, 2007.
7.Penick SB, Carrier RN, Sheldon JB. Metronidazole in the treatment of alcoholism. Am J Psychiatry 1969 Feb;125(8):1063-6.
8.Taylor JA. Metronidazole--a new agent for combined somatic and psychic therapy of alcoholism. A case study and preliminary report. Bull Los Angel Neuro Soc 1964 Sep;29:158-62.
9.Lehmann HE, Ban TA, Naltchayan E. Metronidazole in the treatment of the alcoholic. Psychiatr Neurol (Basel) 1966;152(6):395-401.
10.Alexander I. 'Alcohol-antabuse' syndrome in patients receiving metronidazole during gynaecological treatment. Br J Clin Pract 1985 Jul; 39(7):292-3.
11.Giannini AJ, DeFrance DT. Metronidazole and alcohol--potential for combinative abuse. J Toxicol Clin Toxicol 1983 Jul;20(5):509-15.
12.Edwards DL, Fink PC, Van Dyke PO. Disulfiram-like reaction associated with intravenous trimethoprim-sulfamethoxazole and metronidazole. Clin Pharm 1986 Dec;5(12):999-1000.
13.Plosker GL. Possible interaction between ethanol and vaginally administered metronidazole. Clin Pharm 1987 Mar;6(3):189, 192-3.
14.Gelder MG, Edwards G. Metronidazole in the treatment of alcohol addiction. A controlled trial. Br J Psychiatry 1968 Apr;114(509):473-5.
15.Goodwin DW. Metronidazole in the treatment of alcoholism: a negative report. Am J Psychiatry 1967 Apr;123(10):1276-8.
16.Egan WP, Goetz R. Effect of metronidazole on drinking by alcoholics. Q J Stud Alcohol 1968 Dec;29(4):899-902.
17.Gallant DM, Bishop MP, Camp E, Tisdale C. A six-month controlled evaluation of metronidazole (Flagyl) in chronic alcoholic patients. Curr Ther Res Clin Exp 1968 Feb;10(2):82-7.
18.Platz A, Panepinto WC, Kissin B, Charnoff SM. Metronidazole and alcoholism. (An evaluation of specific and non specific factors in drug treatment). Dis Nerv Syst 1970 Sep;31(9):631-6.
19.Strassman HD, Adams B, Pearson AW. Metronidazole effect on social drinkers. Q J Stud Alcohol 1970 Jun;31(2):394-8.
20.Lowenstam I. Metronidazole and placebo in the treatment of chronic alcoholism. A comparative study. Psychosomatics 1969 May-Jun;10(3):43-5.
21.USFood and Drug Administration (FDA). Docetaxel: Drug Safety Communication - May Cause Symptoms of Alcohol Intoxication. available at: http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHuman MedicalProducts/ucm402106.htm June 20, 2014.