What is febuxostat?
Febuxostat (brand name Uloric) is a medication used to lower uric acid in people with chronic gout. Like allopurinol, it is a xanthine oxidase inhibitor — it blocks the enzyme responsible for producing uric acid. However, febuxostat has a different chemical structure, which makes it a valuable option for patients who cannot tolerate allopurinol or whose uric acid levels have not reached target with allopurinol alone.
Febuxostat is a long-term prevention medication. It does not treat acute gout flares — it works over time to lower uric acid, dissolve existing crystals, and prevent future attacks.
How to take it
- Once daily, with or without food
- Starting dose: usually 40 mg per day
- If your uric acid has not reached the target (below 6 mg/dL) after 2–4 weeks, your doctor may increase the dose to 80 mg per day
- Take it at the same time each day for consistency
What to expect when starting
Just like allopurinol, starting febuxostat can trigger gout flares during the first weeks to months. This paradoxical effect happens because changing uric acid levels can destabilize existing crystal deposits, provoking inflammation.
This is expected and does not mean the medication is failing. Your doctor will prescribe prophylactic colchicine or an NSAID for the first 3–6 months to minimize these flares.
Full benefit builds gradually. It may take several months of consistent use for uric acid to stay at target and for flare frequency to decrease meaningfully.
Lab monitoring
Your doctor will order regular blood work while you take febuxostat:
- Liver function tests (LFTs) — febuxostat can occasionally cause liver enzyme elevations. These are typically checked before starting and periodically during treatment.
- Uric acid level — to confirm you have reached and are maintaining your target
- Kidney function — periodic monitoring
Side effects to watch for
Common:
- Gout flares during the first months — expected and managed with prophylactic therapy
- Nausea
- Joint pain (not related to gout)
- Rash — report any rash to us; while the severe hypersensitivity seen with allopurinol is much less common with febuxostat, rashes still warrant evaluation
- Liver enzyme elevation — usually mild and detected on blood work before causing symptoms
The cardiovascular question:
In 2019, the FDA added a boxed warning to febuxostat based on the CARES trial, which found a slightly higher rate of cardiovascular death in patients taking febuxostat compared to allopurinol. However, multiple subsequent studies — including FAST, LEAF, and other large analyses — have not found a cardiovascular safety signal with febuxostat. The original CARES trial had significant methodological limitations, and the growing body of evidence suggests the initial concern may not reflect a real risk.
Here is what this means in practical terms:
- The FDA warning remains on the label, but the weight of current evidence does not support an increased cardiovascular risk from febuxostat compared to allopurinol.
- Your doctor has prescribed febuxostat because, in your case, effective uric acid lowering is important, and the cardiovascular concern has not been confirmed by subsequent research.
- If you have a history of heart disease or significant cardiovascular risk factors, your doctor has already factored this into the decision.
We believe in being transparent about these findings rather than glossing over them. If you have concerns, let us discuss them together.
Things to avoid
- Azathioprine (Imuran) and mercaptopurine (6-MP) — febuxostat increases levels of these drugs just like allopurinol does, leading to potentially dangerous toxicity. If you take either medication, tell your doctor immediately.
- Alcohol — while febuxostat itself does not interact with alcohol, beer and liquor raise uric acid levels and work against the purpose of therapy. Moderation is important.
- Do not stop and restart abruptly — consistent daily use gives the best results. Gaps in therapy can provoke flares and slow your progress.
Frequently asked questions
Why wasn’t I started on febuxostat first instead of allopurinol? Because of the FDA boxed warning regarding cardiovascular safety, febuxostat is generally reserved for patients who have tried allopurinol and either could not tolerate it or did not reach their uric acid target. Allopurinol has a much longer track record and remains first-line therapy for most patients.
Does febuxostat have the same allergy risk as allopurinol? The severe hypersensitivity syndrome (DRESS/AHS) associated with allopurinol — particularly linked to the HLA-B*5801 genetic variant — is not a significant concern with febuxostat. This is one of febuxostat’s advantages for patients from populations where that allele is more common (Southeast Asian, African American, Korean descent).
How long will I need to take febuxostat? Like allopurinol, febuxostat is typically a lifelong medication. Gout is a chronic condition, and stopping urate-lowering therapy allows uric acid levels to climb again.
Can I take febuxostat if I have kidney disease? Yes. Unlike allopurinol, febuxostat is primarily metabolized by the liver, so no dose adjustment is needed for mild to moderate kidney impairment. This can be an advantage for patients with reduced kidney function.
What if I get a gout flare while on febuxostat? Do not stop the medication. Treat the flare with colchicine, an NSAID, or a corticosteroid as directed by your doctor. Stopping and restarting febuxostat will only prolong the adjustment period and trigger more flares.
This handout is for informational purposes only and does not replace the advice of your physician. Always follow your doctor’s specific instructions about your medications. If you have questions or concerns, contact Synergy Rheumatology & Wellness.