allopurinol vs febuxostat
Side-by-side comparison of allopurinol and febuxostat Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Zyloprim
Uloric
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.
Febuxostat (Uloric) helps manage high uric acid levels in adults with gout. It is used when allopurinol doesn't work well, causes problems, or isn't a good option.
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.
Febuxostat treats high uric acid levels in adults who have gout. Gout is a type of arthritis that causes sudden, severe pain, swelling, and redness in your joints. This medicine is for people who can't take allopurinol, or for whom allopurinol doesn't work well enough.
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.
Febuxostat lowers uric acid levels in your body. It does this by blocking an enzyme called xanthine oxidase. This enzyme helps make uric acid, so blocking it reduces uric acid production.
- • Diarrhea
- • Nausea
- • Increased liver enzyme levels
- • Gout attacks
- • Skin rash
- • Abnormal liver function tests
- • Nausea
- • Joint pain
- • Rash
- Diarrhea 8,423
- Tiredness 7,965
- Difficulty breathing 7,659
- Feeling sick to your stomach 7,061
- Death 6,664
- Diarrhea 849
- Nausea 841
- Sudden kidney damage 837
- Rash 783
- Using the medicine for a condition it is not approved for 715
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.
Febuxostat may increase the risk of death from heart problems in people with existing heart disease. Talk to your doctor about the risks and benefits of taking febuxostat. Febuxostat should only be used if allopurinol doesn't work well, causes problems, or isn't a good option for you.
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.
It is not known if febuxostat can harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if febuxostat passes into breast milk. Talk to your doctor about the best way to feed your baby if you are taking this medicine.
How to Read This allopurinol vs febuxostat Comparison
allopurinol is classified in the Xanthine Oxidase Inhibitor drug class, while febuxostat sits within the Xanthine Oxidase Inhibitor class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. 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 febuxostat has 4,025. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. 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 febuxostat — 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.