Is it safe to consume alcohol 48 hours after taking Metronidazole (Flagyl) and would vomiting be a severe reaction requiring emergency department (A&E) visit?

From the Guidelines

It is generally safe to drink alcohol 48 hours after taking metronidazole, and you would not need to go to A&E for vomiting that might occur. Metronidazole typically stays in your system for about 24-48 hours after your last dose, so waiting 48 hours should be sufficient to avoid the disulfiram-like reaction that can occur when alcohol is combined with this medication. This reaction happens because metronidazole interferes with the breakdown of alcohol in your body, causing a buildup of acetaldehyde which leads to symptoms like nausea, vomiting, flushing, headache, and rapid heart rate 1. If you do experience vomiting after drinking alcohol following metronidazole use, it can usually be managed at home with rest, hydration, and over-the-counter anti-nausea medications unless symptoms are severe or persistent. Some key points to consider include:

• The Centers for Disease Control and Prevention recommend avoiding alcohol during treatment with metronidazole and for 24 hours thereafter 1
• Severe symptoms such as chest pain, difficulty breathing, or confusion would warrant seeking emergency care
• To be extra cautious, some medical professionals recommend waiting up to 72 hours after finishing metronidazole before consuming alcohol
• It's essential to prioritize your health and consult with a medical professional if you have any concerns or questions about taking metronidazole and consuming alcohol.

From the FDA Drug Label

Alcoholic beverages should be avoided while taking metronidazole tablets and for at least one day afterward. Alcoholic beverages should not be consumed during metronidazole therapy and for at least one day afterward because abdominal cramps, nausea, vomiting, headaches, and flushing may occur

It is not ok to drink alcohol 48 hours after taking metronidazole, as the drug label recommends avoiding alcohol for at least one day after taking the medication. If you experience vomiting after consuming alcohol while taking metronidazole, you should seek medical attention, which may include going to A&E. 2

From the Research

Metronidazole and Alcohol Consumption

• It is generally recommended to avoid consuming alcohol while taking metronidazole and for a certain period after finishing the treatment, as it can cause a disulfiram-like reaction 3.
• This reaction can lead to symptoms such as nausea, vomiting, and headaches.
• The exact duration for which alcohol should be avoided after taking metronidazole is not specified in the provided studies, but it is usually recommended to wait at least 24-48 hours after finishing the treatment.

Vomiting as a Reaction to Metronidazole and Alcohol

• Vomiting can be a symptom of the disulfiram-like reaction caused by consuming alcohol while taking metronidazole 3.
• If vomiting occurs as a reaction to metronidazole and alcohol, it is not necessarily a reason to go to A&E, but it is recommended to seek medical attention if the symptoms are severe or persistent.
• In general, if you experience any severe or unusual symptoms while taking metronidazole, you should consult your doctor or seek medical attention.

Pharmacokinetics of Metronidazole

• Metronidazole is extensively metabolized by the liver and has a high oral bioavailability 4.
• The drug is eliminated mainly through the kidneys, and its metabolism can be affected by factors such as liver dysfunction and renal failure 4.
• The pharmacokinetics of metronidazole can vary among different patient groups, such as preterm and term infants, children, and elderly patients 4.