Can you drink alcohol while taking metronidazole?

You are generally not advised to drink alcohol while suffering from any kind of infection, particularly if you are treating it with antibiotics.

Consuming alcohol while fighting an infection can cause unpleasant side effects, such as sleeping issues, dehydration and slowing down your body’s healing process against the infection.

Drinking alcohol while taking metronidazole can cause interactions that lead to adverse effects. This guide will look at how metronidazole interacts with alcohol and the side effects you can experience as a result of combining the two.

How does metronidazole and alcohol interact?

Metronidazole 400mg tablets are antibiotics that are commonly prescribed to treat the symptoms of bacterial vaginosis among others.

Metronidazole can cause side effects whether you drink alcohol during your course of treatment or not. Side effects while taking metronidazole are usually uncommon. Any side effects you do experience during treatment will normally be mild and go away on their own.

Metronidazole is classed as a disulfiram-like drug, which means that it causes an adverse reaction to alcohol. Combining metronidazole with alcohol or drinking alcohol within three days of stopping treatment can increase the risk of experiencing more side effects.

Disulfiram-like Reaction

Drinking alcohol while taking metronidazole can, in some cases cause a disulfiram-like reaction, which is a reaction that can cause several very unpleasant symptoms.

Disulfiram-like side effects include:

• nausea
• vomiting
• abdominal discomfort
• flushing of the face and chest area
• tachycardia (increased heart rate)
• fainting
• throbbing headaches

Warnings and interactions with alcohol containing medicines

A 2019 study into the disulfiram-like reaction between Metronidazole and alcohol, found that many commonly used prescription and over the counter drugs containing alcohol can also contribute to a disulfiram-like reaction. 

The study found that the use of alcohol containing medicines with metronidazole can cause discomfort and adverse reactions for the patient undergoing treatment.

The alcohol content of prescription and over the counter drugs is often overlooked when it comes to alcohol warnings and drug interactions for Metronidazole.

Over the counter drugs containing alcohol that interact with Metronidazole:

• Imodium
• Benadryl
• Vicks Nyquil Liquid

For a full list of alcohol containing OTC and prescription medicines that interact with Metronidazole, we recommend visiting the official research page.

What are the side effects?

Metronidazole can cause some side effects on its own, such as:

• Nausea
• Vomiting
• Thrush
• Diarrhoea

These side effects are normally mild and can occur whether or not you drink alcohol while taking this medication.

However, drinking alcohol within three days of taking this medicine can also cause further side effects:

• Facial flushing
• Abdominal cramps
• Chest pain
• Breathing problems
• Rapid heart rate

You may also experience severe side effects that may require medical attention, which include:

• Liver damage
• Sudden drop in blood pressure

Does alcohol affect how well metronidazole will work?

While the combination of alcohol and antibiotics like metronidazole can cause unpleasant and unwanted side effects, it is not likely to make the medicine less effective if consumed in moderation.

Your liver metabolises alcohol, as it does with certain medicines. Therefore, consuming large quantities of alcohol may change the enzymes in the liver and alter how your body breaks down the medication.

If you drink a lot of alcohol on a regular basis, your enzyme levels may be “induced”, which means they break down a drug at a faster rate, which may decrease their level in your body. If this occurs while taking an antibiotic like metronidazole, it could mean that the medicine is not as effective at fighting the infection. For this reason, you are advised to not drink alcohol at all while taking antibiotics.

Can I drink alcohol after finishing a course of metronidazole?

You should wait for at least three days after completing your course of metronidazole before you consume alcohol. This will ensure the medicine is out of your system and has had time to properly fight the infection.

Drinking before this time may mean that alcohol can still interact with any medicine still in your system, which may hinder the effects of metronidazole and lessen its effectiveness.

Completing your full course of antibiotic treatment safely

Taking an antibiotic medicine like metronidazole should be sufficient to treat your infection. A lot of people who take antibiotics such as this one notice their symptoms clearing several days before their course of treatment is due to end. However, even if you feel better and have no visible symptoms, it is vital that you continue to take metronidazole for as long as your doctor has instructed you to.

Failing to complete your course of treatment may mean that the infection has not been completely eradicated from the body, which could cause it to come back.

Even if you experience side effects, you should not stop taking metronidazole unless your doctor advises you to do so.

A modern worldwide concern is that of antibiotic resistance, which is when bacteria is able to fight against the medication that is taken to kill them. As a result, the bacteria is able to grow and remain in the body. This can occur in people of all ages. Therefore, it is important to speak to your doctor if you do not believe that your medication is working to fight your infection.

Summary

In conclusion, it is always recommended that you do not drink alcohol while taking an antibiotic medicine like metronidazole. Avoiding alcohol during your course of treatment, and for the first few days after treatment has ended, will remove the additional risk of side effects, making it more likely that your treatment will be problem-free and effective.

However long your doctor prescribes metronidazole for you to take, you should not stop taking it until you have completed the course they prescribed for you. This will ensure the infection is cleared completely. If you do not feel that metronidazole is making a difference to your condition, you should tell your doctor.

Always consult the patient information leaflet for comprehensive details on warnings and interactions before you begin taking a new medicine. Ask your doctor or pharmacist if you are unsure about any aspect of your treatment.

Sources

Metronidazole on the NHS website

https://www.healthline.com/health/bad-buzz-metronidazole-flagyl-and-alcohol#TOC_TITLE_HDR_1

Patient Information Leaflet