Can You Drink on Metronidazole?

It’s a common story: you go to a doctor, walk away with a prescription for your condition, then drive to your local pharmacy to pick it up. You’re excited, thinking how much better you’ll feel soon. You take it out of the crinkly paper bag, tear off what seems like an entire stack of papers with information in tiny print stapled onto it, and glance at it before tossing it into the recycling bin. Then something on the orange bottle catches your eye — that little wine glass with a line across it: “Don’t consume with alcohol!”

Yikes. It’s too late to get all those papers back to find out why, so you take your questions to Google: “Can you drink on metronidazole?” It’s probably not that bad, right? What’s all this about the disulfiram-like reaction between metronidazole and booze? Before you give yourself a panic attack searching for things like “Can metronidazole and alcohol kill you?” let’s get the facts straight. What exactly happens if you accidentally drink alcohol while taking metronidazole?

What Is Metronidazole?

According to the National Library of Medicine, metronidazole (better known by the brand name Flagyl) is one of the go-to drugs for the treatment of infections. It’s equipped to handle several conditions: 

• Intestinal amebiases
• Liver amebiasis
• Bacterial septicemia
• Bone and joint infections
• Meningitis
• Brain abscess
• Endocarditis
• Endometritis
• Bacterial vaginosis
• Intra-abdominal infections
• Lower respiratory tract infections
• Skin structure infections
• Surgical prophylaxis colorectal surgeries

That’s quite a long job description! And there’s even more. Topical metronidazole can treat a few gnarly infections, such as rosacea and bacterial vaginosis. Plus, it has several off-label uses: 

• Bite wound infections from animals
• Infections from human bites (eek!)
• Clostridioides (formerly Clostridium difficile)
• Crohn’s disease
• Postsurgical resection management
• Giardiasis
• Periodontitis
• Tetanus

How Does Metronidazole Work?

Flagyl works by attacking bacterial DNA through a four-step process. Here’s the gist:

1. Breaking the barrier and taking out the anaerobes. Metronidazole breaks through the cell barriers of anaerobic and aerobic bacteria but only kills the first type of pathogen.
2. Upgrading equipment. With the anaerobes out of the way, it’s time to attack the second enemy! However, this requires different equipment. Metronidazole undergoes reductive activation by special proteins, which change its chemical structure to allow it to torpedo the aerobes.
3. Storming the command center. The next step? Destroying the “enemy’s” DNA. Metronidazole interacts with the host cells’ DNA, resulting in breakage and “fatal destabilization.”
4. Cleaning up the mess. Final step? Breaking down the toxic byproducts of the reaction.

While metronidazole is quickly absorbed, it might take a couple of days to start feeling better. However, once it gets going, the medication does a powerful job of clearing out the infection.

Can You Drink on Metronidazole?

In general, Flagyl doesn’t mix well with other substances, including alcohol. This isn’t all that surprising — for one thing, alcohol tends to intensify the side effects of many medications. In the case of metronidazole, there are quite a few:

• Headaches. Many people on metronidazole experience headaches. Since alcohol is known for causing the notorious “cocktail headaches,” adding it to the mix isn’t doing us any favors.
• Digestive disruption. Some have gastrointestinal effects, including loss of appetite, nausea and vomiting, diarrhea, heartburn, or cramping in the stomach area, and constipation while taking metronidazole. Alcohol can disrupt digestion, causing nausea, heartburn, and even leading to gastritis. Needless to say, this makes for a potentially stomach-turning combo!
• Metallic taste. Metronidazole might also cause a metallic taste in our mouth — so whatever we’re drinking might not taste that great.

In addition to these common side effects, there are some potentially serious (but rare) side effects of metronidazole that don’t mix well with booze: 

• Seizures. The potentially serious side effects of metronidazole include seizures. In large amounts, alcohol has been known to induce seizures as well (as does alcohol withdrawal), so combining the two could be even more dangerous. It’s important to stay vigilant and be aware of telltale symptoms such as unusual behaviors or sensations, uncontrollable movements, or, in severe cases, loss of consciousness.
• Cancer risk. As the warning label on metronidazole says, it may also be carcinogenic based on animal studies. Given that alcohol is a known carcinogen as well, the combo isn’t great.
• Possible brain damage. If used for a long time, metronidazole could be neurotoxic. Knowing what alcohol does to our brain, the mixture of the two could cause serious trouble.

Metronidazole and Alcohol: What Else Is Behind the Warning?

If you’re taking disulfiram — a medication used to treat alcohol use disorder (AUD) — there’s yet another reason to pause and reconsider before taking metronidazole.

Disulfiram works by causing extremely unpleasant side effects, such as facial flushing, nausea, and cardiovascular abnormalities. The idea is that taking disulfiram will make drinking so unenjoyable we won’t want to do it anymore. (For more details, check out our blog “How Does Disulfiram Work?”)

What does any of this have to do with Flagyl? As it turns out, metronidazole has a negative, and potentially dangerous, interaction with both alcohol and disulfiram.

Let’s look at both effects in a bit more detail:

1. Metronidazole is thought to induce a “disulfiram-like” reaction when mixed with alcohol. When we combine alcohol with metronidazole, we might experience nausea, vomiting, stomach cramps, headaches, and facial flushing. According to a recent study, it doesn’t make much to trigger the reaction!
2. Metronidazole also doesn't mix well with disulfiram. Taking both medications puts us at risk of hallucinations and psychosis (definitely not what we want, especially when we’re already not feeling our best!).

Negative Interactions Between Metronidazole and Alcohol: Myth or Science?

Some scientists now think that the side effects of mixing metronidazole and alcohol are a myth. 

According to an Emergency Medical News article, doctors have been warning patients against mixing the two for years to avoid a “disulfiram-like reaction.” And yet, the author asks:
 

“If this interaction is so important, where were the cases? Millions of prescriptions for metronidazole are written each year. Despite clear warnings, it's inevitable that a significant number of patients would continue to consume alcohol with the drug. Yet I've never seen a patient come in with a disulfiram-like reaction from that combination. Is the metronidazole-ethanol drug interaction really a thing?”

The author goes on to explain how the accumulation of acetaldehyde is responsible for the disulfiram reaction and how the “original thinking” was that metronidazole also blocked its breakdown. However, as he points out, recent evidence shows that this might not be the case. When 18 patients who were on metronidazole were compared with a control group who had a similar blood alcohol concentration, none seemed to show any signs of a disulfiram-like reaction. 

Likewise, a study in WMJ set out to investigate whether or not there was any truth to the disulfiram-like reaction claims and found that the answer isn’t as clear as scientists once thought. Their findings suggest that there’s no increase in acetaldehyde when both substances are present in our system.

How Long After Taking Metronidazole Can I Drink Alcohol?

Still, disulfiram-like reaction or not, metronidazole does interact with alcohol in potentially problematic ways, so the recommended wait period is at least two weeks for disulfiram and three days for alcohol after taking it. 

What If I Already Had a Drink?

Some of us might be thinking, “Oh no! What if I already had a drink before that warning label on the medicine package caught my eye?”

First of all, don’t panic. This probably happens quite often, and usually leads to no harmful effects, according to the Emergency Medical News study. However, it’s good to keep in mind that this is just one study arguing against the negative effects, and even if the “metronidazole and alcohol myth” is responsible for the alcohol warning, there are still other reasons why Flagyl and alcohol are not a good mix.

So, can metronidazole and alcohol kill you? It almost certainly won’t, especially given the evidence that there might not be a disulfiram-like reaction at play after all. 

Still, it’s best to stay vigilant and avoid mixing metronidazole and alcohol. And if there’s any doubt in your mind at all that you’re having a dangerous reaction, please don’t hesitate to call your doctor immediately! There are many individual factors at play here, so erring on the side of safety is key.

Tips To Stay Safe

So, how can we stay safe while taking metronidazole as we’re trying to stay away from booze for the time being (or, perhaps, for even longer)? Here are a few ideas:

1. Avoid the mix. Mixing alcohol and metronidazole is asking for trouble. Instead, focus on healing and nourishing your body with plenty of water and vitamin-rich foods. You’ll heal faster and your body will thank you!
2. Follow your doctor’s advice. Always follow your physician’s advice about taking medications, and don’t hesitate to ask if you have questions. They’re there to help!
3. Get support. If you’re having trouble staying booze-free, find like-minded people who will be happy to support you. They can be friends, family members, or others just like you who are already part of the Reframe community! Everyone’s alcohol journey is different, so whatever your goals are, you’re bound to find helpful advice and support.
4. Get sober curious. Use this time as an opportunity to explore a sober-curious lifestyle. Approach it as an experiment — what if instead of having a glass of wine with dinner you had a fun mocktail instead? Who knows, you might find a new favorite! Plus, a hydrating, nutritious drink is bound to make you feel better as you heal.

Summing Up

In the end, as with any situation that compels us to set alcohol aside for a bit, it’s always best to see the situation as an opportunity. Perhaps it’s even a blessing in disguise! Who knows, by going booze-free for a few days or weeks, you might discover new activities you love or find that you enjoy waking up feeling refreshed. Maybe your skin looks better or maybe you’ve even dropped some weight. All in all, you might see that cutting back is something you want to continue in the long run to see what new benefits are waiting for you (and trust us, there are lots!). If so, Reframe is here to help you and cheer you on every step of the way.