Augmentin Drug Interactions You Should Know About

When your doctor prescribes Augmentin (Amoxicillin/Clavulanate), it's important to make sure it won't interfere with other medications you're taking. Drug interactions can reduce how well a medication works, increase side effects, or even cause dangerous reactions.

This guide covers the most important Augmentin drug interactions — including prescription medications, over-the-counter products, supplements, and even food — so you know what to watch for and what to tell your doctor.

How Drug Interactions Work

A drug interaction happens when one substance changes how another substance works in your body. This can happen in several ways:

• One drug increases the effect of another — making side effects more likely or more severe.
• One drug decreases the effect of another — making a medication less effective.
• Two drugs compete for the same pathway — changing how quickly your body absorbs or eliminates them.

Not every interaction is dangerous, and not every combination needs to be avoided. But your doctor and pharmacist need to know everything you're taking so they can make safe decisions.

Medications That Interact With Augmentin

Major Interactions

These interactions have the highest potential for harm and require close monitoring or dosage adjustments:

• Warfarin (Coumadin) — Augmentin can increase the blood-thinning effect of Warfarin, raising your risk of bleeding. If you take Warfarin, your doctor should monitor your INR (a blood clotting test) more frequently while you're on Augmentin.
• Methotrexate — Augmentin can reduce the kidney's ability to clear Methotrexate from your body, leading to higher Methotrexate levels and increased risk of toxicity. Symptoms of Methotrexate toxicity include mouth sores, nausea, and low blood counts. Your doctor may need to monitor blood levels closely.
• Probenecid — Probenecid slows down how quickly your kidneys excrete Amoxicillin, resulting in higher and longer-lasting Amoxicillin levels in your blood. While this isn't always dangerous, your doctor should be aware of the combination.
• Allopurinol (Zyloprim) — Taking Allopurinol with Augmentin increases the risk of developing a skin rash. This interaction is well-documented but not always clinically significant. Still, let your doctor know if you take Allopurinol for gout.

Moderate Interactions

These interactions are worth knowing about but are generally manageable:

• Oral contraceptives (birth control pills) — There has been long-standing concern that antibiotics like Augmentin may reduce the effectiveness of hormonal birth control. While recent research suggests this effect is minimal for most antibiotics, some healthcare providers still recommend using backup contraception (such as condoms) during your course of Augmentin and for 7 days after finishing.
• Tetracyclines (Doxycycline, Minocycline) and Macrolides (Azithromycin, Erythromycin) — These antibiotics work by a different mechanism (stopping bacterial protein synthesis) and can potentially antagonize the bactericidal (bacteria-killing) action of Amoxicillin. In general, doctors avoid prescribing these together.
• Mycophenolate Mofetil (CellCept) — Augmentin may reduce blood levels of Mycophenolate, an immunosuppressant used after organ transplants. If you take Mycophenolate, your transplant team should be involved in any antibiotic decisions.

Supplements and OTC Products to Watch

Some over-the-counter products and supplements can also interact with Augmentin:

• Probiotics — While often recommended alongside antibiotics, take probiotics at least 2 hours apart from your Augmentin dose. If taken together, the antibiotic can kill the probiotic bacteria before they reach your gut.
• Antacids and acid-reducing medications — High-dose antacids containing aluminum or magnesium may slightly reduce Augmentin absorption. This is generally not a major concern, but spacing them apart by 1-2 hours is a good practice.
• Vitamin K supplements — Since Augmentin can affect Warfarin levels, adding or changing Vitamin K supplements during treatment could further complicate blood clotting management. Talk to your doctor if you take both.

Food and Drink Interactions

Augmentin has relatively few food interactions, which is one reason it's considered a convenient antibiotic:

• Take with food. This is not just a suggestion — taking Augmentin at the start of a meal significantly reduces stomach upset and improves absorption of the Clavulanate component. This is the most important food-related instruction for Augmentin.
• Alcohol. There is no direct chemical interaction between Augmentin and alcohol. However, drinking alcohol while fighting an infection can worsen nausea, increase the risk of stomach upset, and put extra strain on your liver. Most doctors recommend limiting or avoiding alcohol during antibiotic treatment.
• No specific food restrictions. Unlike some antibiotics (such as Tetracyclines with dairy), Augmentin does not have specific food restrictions. You can eat normally while taking it.

What to Tell Your Doctor

Before starting Augmentin, make sure your doctor and pharmacist know about:

1. All prescription medications you currently take — especially blood thinners, Methotrexate, immunosuppressants, and gout medications.
2. Over-the-counter medications — including pain relievers, antacids, and allergy medications.
3. Supplements and vitamins — especially probiotics, Vitamin K, and herbal products.
4. Allergies — particularly any history of allergic reactions to Penicillin, Amoxicillin, Cephalosporins, or other antibiotics.
5. Medical conditions — especially kidney disease, liver disease, or a history of Clostridium difficile (C. diff) infection.

Your pharmacist will also run an automatic drug interaction check when they fill your prescription. If a significant interaction is flagged, they'll contact your doctor to discuss alternatives or dosage adjustments.

Final Thoughts

Augmentin is generally a safe and well-tolerated antibiotic, but like any medication, it can interact with other drugs. The most important interactions to know about involve Warfarin (increased bleeding risk), Methotrexate (increased toxicity), and Probenecid (higher Amoxicillin levels). Always take Augmentin with food, and make sure every healthcare provider you see knows your complete medication list.

For more information, read our guides on Augmentin side effects and what Augmentin is used for. If you need help finding Augmentin in stock, visit Medfinder.