4 Augmentin (Amoxicillin / Clavulanate) Interactions You Should Know About

If you’ve had a bacterial infection before, you may have taken Augmentin (amoxicillin / clavulanate). It’s a common antibiotic that combines two medications into a single treatment.

Amoxicillin is a penicillin antibiotic that can be prescribed by itself. And clavulanate is an ingredient that blocks amoxicillin from being inactivated in your body. This makes amoxicillin more effective.

Augmentin is helpful for a variety of bacterial infections. But it has some risks to keep in mind, including drug interactions. Here, we’ll cover four of the most important Augmentin interactions to be aware of.

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1. Alcohol

Drug interactions may occur between two or more medications, but they can also happen with food and drinks. Alcohol is a common culprit. It can interact with many medications, including antibiotics.

Certain antibiotics make it harder for your body to break down alcohol. This may result in potentially serious side effects. In other cases, alcohol can worsen medication side effects. This is the case with Augmentin.

Both Augmentin and alcohol can cause gastrointestinal (GI) discomfort, such as nausea and vomiting. So combining alcohol with Augmentin can make these GI effects worse.

Plus, alcohol weakens the immune system. This makes it harder for antibiotics to do their job. So avoiding alcohol while taking antibiotics can help you recover faster from your infection.

2. Warfarin

Warfarin (Coumadin, Jantoven) is a blood thinner medication that helps prevent blood clots. Warfarin can interact with many foods and medications. Augmentin is no exception.

Augmentin increases your chances of experiencing warfarin side effects, including bruising and bleeding. These effects can be even worse if you take other medications that can increase bleeding. For example, certain pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs), carry this risk. This includes medications like ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn).

If you take warfarin, you’re likely completing blood tests regularly to make sure your warfarin dose is appropriate. If you’re starting Augmentin, your healthcare provider may ask you to complete more frequent blood tests. They’ll adjust your warfarin dose if needed.

You should also watch for signs of bleeding and bruising. This includes watching for bruises with no known cause, nose bleeds, and bleeding that lasts longer than 10 minutes.

3. Probenecid

Probenecid is a medication that treats gout. If you take Augmentin with probenecid, amoxicillin levels in your body may become too high. This can lead to a higher risk of amoxicillin side effects, including nausea, diarrhea, and headache.

Your healthcare provider will likely recommend avoiding Augmentin if you take probenecid. They can recommend a different antibiotic to treat your bacterial infection. 

4. Allopurinol

Allopurinol (Zyloprim) is another medication that treats gout. Like Augmentin, it can cause a skin rash as a side effect. In rare but severe cases, a skin rash can be a sign of Stevens-Johnson syndrome (SJS) or drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. These are severe medication-related reactions that need urgent medical treatment.

A rash from SJS may be flat, with dark red, purple, or brown patches that are painful. Your skin may peel, and sores may present in the mouth, eyes, and genitals. You may also have a fever and body aches. A rash from DRESS may feel itchy and appear as red, brown, or purple patches or bumps. You may also have swelling, fever, and enlarged lymph nodes.

Since both Augmentin and allopurinol can cause skin rashes, you’re more likely to develop a rash if you take them together. If you develop a rash during treatment with these medications, contact your healthcare provider right away. You may need to stop taking one or both medications.

Can Augmentin make hormonal birth control less effective?

No. Penicillin antibiotics, including amoxicillin, don’t make hormonal birth control less effective.

Penicillin antibiotics can affect your gut bacteria. And this can affect how your body absorbs estrogen and progestin ingredients in birth control. But research shows that the impact isn’t enough to make hormonal birth control ineffective.

However, there are some antibiotics that can affect how well hormonal birth control works. This includes rifampin (Rimactane) and rifabutin (Micobutin).

When should you contact your healthcare provider about an Augmentin interaction?

If you have any side effects while taking Augmentin, let your healthcare provider know. Side effects may be a sign of an Augmentin interaction. This includes nausea and vomiting. It also includes bruising, bleeding, and skin rashes. And remember that combining Augmentin and alcohol can increase your risk of side effects.

Before starting Augmentin, let your healthcare provider and pharmacist know all medications you take. This includes prescription medications and over-the-counter medications, such as vitamins, supplements, and herbal products. They can review your medication list and let you know if any potential interactions exist.

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Written by:

Nabila Ismail, PharmD

Nabila Ismail, PharmD, is a pharmacist, freelance medical writer, and marketing strategist. She graduated with a doctorate in pharmacy from the University at Buffalo.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

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