PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

allopurinol vs amoxicillin/clavulanate

Side-by-side comparison of allopurinol and amoxicillin/clavulanate. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

moderate Known Drug Interaction

( 7.1 ) Concomitant use of AUGMENTIN and oral anticoagulants may increase the prolongation of prothrombin time.( 7.2 ) Co-administration with allopurinol increases the risk of rash. 7.3 Allopurinol The concurrent administration of allopurinol and amoxicillin increases the incidence of rashes in patients receiving both drugs as compared to patients receiving amoxicillin alone. It is not known whether this potentiation of amoxicillin rashes is due to allopurinol or the hyperuricemia present in these patients.

Recommendation: Watch your skin closely for any new rashes and tell your doctor immediately if one appears. Your doctor may need to monitor your reaction to these medications.

Drug Class
allopurinol Xanthine Oxidase Inhibitor
amoxicillin/clavulanate Penicillin / Beta-Lactamase Inhibitor Combination
Type
allopurinol Prescription
amoxicillin/clavulanate Prescription
Summary
allopurinol

Allopurinol is a medicine that lowers uric acid levels in your body. It helps prevent gout attacks and other problems caused by high uric acid.

amoxicillin/clavulanate

Augmentin is a combination of two medicines, amoxicillin and clavulanate. It is an antibiotic that fights bacteria in your body.

What It Treats
allopurinol

This medicine is used to manage gout in adults. Gout causes painful attacks, joint damage, and kidney problems. Allopurinol is also used in adults and children with leukemia, lymphoma, and solid tumors who are getting cancer treatment. It helps manage high uric acid caused by the cancer treatment. It can also help adults who get calcium oxalate kidney stones often.

amoxicillin/clavulanate

Augmentin treats infections caused by bacteria. It is used for infections such as lower respiratory infections, ear infections, sinus infections, skin infections, and urinary tract infections. This medicine will not work for viral infections, such as colds or the flu.

How It Works
allopurinol

Allopurinol works by blocking an enzyme called xanthine oxidase. This enzyme helps your body make uric acid. By blocking it, allopurinol reduces the amount of uric acid in your blood and urine.

amoxicillin/clavulanate

Amoxicillin kills bacteria. Clavulanate helps amoxicillin work better by preventing bacteria from breaking down amoxicillin. This combination helps to fight a wider range of bacteria.

Common Side Effects
allopurinol
  • Diarrhea
  • Nausea
  • Increased liver enzyme levels
  • Gout attacks
  • Skin rash
amoxicillin/clavulanate
  • Diarrhea or loose stools
  • Nausea
  • Skin rashes
  • Hives
  • Vomiting
FAERS Reports
allopurinol
  • Diarrhea 8,423
  • Tiredness 7,965
  • Difficulty breathing 7,659
  • Feeling sick to your stomach 7,061
  • Death 6,664
amoxicillin/clavulanate
  • Long-term kidney disease 4,661
  • Sudden kidney damage 4,200
  • Diarrhea 4,083
  • Drug allergy 3,744
  • Feeling sick to your stomach 3,700
Serious Warnings
allopurinol

Allopurinol can cause serious skin reactions that can be deadly. Stop taking this medicine and get medical help right away if you get a skin rash or any other signs of an allergic reaction.

amoxicillin/clavulanate

Augmentin can cause serious allergic reactions, including fatal ones. Stop taking Augmentin and get medical help right away if you have any signs of an allergic reaction. Augmentin can also cause severe skin reactions. Tell your doctor if you develop a rash. This drug can also cause liver problems and severe diarrhea.

Pregnancy
allopurinol

Allopurinol may harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is not recommended to breastfeed while taking this medicine because it can pass into breast milk.

amoxicillin/clavulanate

Animal studies show Augmentin may be safe during pregnancy, but there are no good studies in pregnant women. Talk to your doctor if you are pregnant or plan to become pregnant. Amoxicillin passes into breast milk and may cause problems for the baby, so talk to your doctor if you are breastfeeding.

Also Compare, Nearby Drugs

Compare allopurinol with

How to Read This allopurinol vs amoxicillin/clavulanate Comparison

allopurinol is classified in the Xanthine Oxidase Inhibitor drug class, while amoxicillin/clavulanate sits within the Penicillin / Beta-Lactamase Inhibitor Combination class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, allopurinol has 37,772 submissions while amoxicillin/clavulanate has 20,388. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known moderate interaction flagged in FDA labeling, attributed to taking these two drugs together increases the chance of developing a skin rash. it is not fully known if the rash is caused by the drugs themselves or the medical condition being treated.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between allopurinol and amoxicillin/clavulanate - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.