What You Should Know About Augmentin Side Effects

If your doctor has prescribed Augmentin (Amoxicillin/Clavulanate), you're probably wondering what to expect. Like all antibiotics, Augmentin can cause side effects — most are mild and manageable, but a few are serious enough to need immediate medical attention.

This guide covers the most common Augmentin side effects based on FDA labeling, explains which warning signs to watch for, and shares practical tips for feeling better while you finish your course of treatment.

What Is Augmentin?

Augmentin is a combination antibiotic that contains two active ingredients: Amoxicillin (a penicillin-type antibiotic) and Clavulanate Potassium (a beta-lactamase inhibitor). Together, they fight a wider range of bacteria than Amoxicillin alone. Augmentin is prescribed for sinus infections, ear infections, urinary tract infections, skin infections, and lower respiratory tract infections.

Common Side Effects

Most people who take Augmentin will experience at least one mild side effect. These are usually not dangerous and tend to go away on their own after you finish your treatment. Common side effects include:

• Diarrhea — the most frequently reported side effect, caused primarily by the Clavulanate component. Affects up to 20-30% of patients.
• Nausea — feeling queasy, especially if you take Augmentin on an empty stomach.
• Vomiting — less common than nausea but can occur, particularly in children.
• Abdominal pain or cramping — mild stomach discomfort during treatment.
• Skin rash — a mild, non-serious rash can occur in some patients.
• Vaginal yeast infection — antibiotics can disrupt normal vaginal flora, leading to yeast overgrowth.
• Headache — occasionally reported during treatment.

Diarrhea is by far the most common complaint. The Clavulanate component in Augmentin is the main culprit — it can irritate the digestive tract and disrupt your gut bacteria.

Serious Side Effects

While rare, some Augmentin side effects require immediate medical attention. Call your doctor or go to the emergency room right away if you experience any of the following:

Severe Allergic Reaction (Anaphylaxis)

Symptoms include difficulty breathing, swelling of the face, lips, tongue, or throat, hives, and a rapid or weak pulse. This is a medical emergency. If you have a history of Penicillin allergy, tell your doctor before taking Augmentin.

Clostridioides Difficile-Associated Diarrhea (CDAD)

If you develop severe, watery diarrhea that won't stop — especially if it contains blood or mucus — this could be a sign of a C. diff infection. This can happen during treatment or even weeks after finishing Augmentin. Contact your doctor immediately.

Liver Problems (Hepatic Dysfunction)

Signs include yellowing of the skin or eyes (jaundice), dark urine, persistent nausea, severe abdominal pain, or unusual fatigue. Augmentin-related liver injury is uncommon but has been documented, particularly with prolonged use.

Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis

These are extremely rare but life-threatening skin reactions. Warning signs include a spreading rash with blistering and peeling skin, sores in the mouth, eyes, or genitals, and fever. Seek emergency care immediately.

Seizures

Very rare, but can occur with high doses or in patients with kidney problems. If you experience a seizure, call 911.

Superinfection

Prolonged antibiotic use can sometimes lead to secondary infections, such as oral thrush or resistant bacterial infections.

Side Effects in Specific Populations

Children

Children are more likely to experience diarrhea and diaper rash. The ES-600 and suspension formulations are dosed by weight. If your child develops persistent vomiting or refuses to eat, contact your pediatrician.

Pregnant and Breastfeeding Women

Augmentin is classified as Pregnancy Category B, meaning animal studies have not shown harm but there are limited human studies. It is generally considered safe during pregnancy when prescribed by a doctor. Small amounts pass into breast milk, but Augmentin is usually compatible with breastfeeding.

Patients With Kidney Problems

If you have impaired kidney function (CrCl below 30 mL/min), your doctor should adjust your dose. The extended-release formulation (Augmentin XR) is not recommended for patients with severe kidney impairment.

Patients With Liver Problems

If you've previously experienced liver problems while taking Augmentin, you should not take it again. Your doctor should monitor liver function if you have pre-existing liver disease.

How to Manage Common Side Effects

Here are practical tips to minimize discomfort while taking Augmentin:

• Take it with food. Always take Augmentin at the start of a meal. This significantly reduces nausea and stomach upset, and it also improves absorption of the Clavulanate component.
• Stay hydrated. Diarrhea can cause dehydration. Drink plenty of water and consider an electrolyte drink if diarrhea is persistent.
• Consider probiotics. Some studies suggest that taking a probiotic supplement (such as Lactobacillus or Saccharomyces boulardii) during antibiotic treatment may help reduce diarrhea. Take the probiotic at least 2 hours apart from your Augmentin dose.
• Watch for yeast infections. If you're prone to vaginal yeast infections, talk to your doctor about using an over-the-counter antifungal treatment preventively.
• Don't skip doses or stop early. Even if you feel better, completing your full course of Augmentin is important to fully clear the infection and prevent antibiotic resistance.
• Avoid alcohol in excess. While there's no strict interaction between Augmentin and alcohol, drinking can worsen nausea and put extra strain on your liver.

If side effects become severe enough that you're considering stopping the medication, call your doctor first. They may adjust your dose, switch you to a different formulation, or recommend an alternative antibiotic.

Final Thoughts

Most Augmentin side effects are mild and temporary — diarrhea, nausea, and stomach discomfort are the most common, and they usually resolve once you finish your prescription. The key is to take Augmentin with food, stay hydrated, and complete your full course of treatment.

However, if you experience signs of a severe allergic reaction, persistent bloody diarrhea, yellowing skin, or a blistering rash, seek medical care right away. These are rare but serious.

For more information about this medication, read our full guide on what Augmentin is and how it works, or learn about Augmentin drug interactions to avoid.