Febuxostat
A non-purine xanthine oxidase inhibitor for chronic gout in people who cannot take allopurinol or do not respond to it.
Drug card
- How it works
- Blocking xanthine oxidase so the body makes less uric acid
- Used for
- Chronic gout when allopurinol fails or is not tolerated
- High uric acid during chemotherapy for blood cancers (EU)
- Known for
- Higher risk of death from heart causes
- Abnormal liver tests and liver failure
- Gout flares when treatment starts
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does febuxostat work?
Febuxostat is a non-purine inhibitor that blocks xanthine oxidase selectively and noncompetitively, so less uric acid is made. At usual doses it does not inhibit other enzymes of purine and pyrimidine metabolism.
Like other xanthine oxidase inhibitors: Xanthine oxidase turns hypoxanthine into xanthine and xanthine into uric acid, the last step of purine breakdown in humans. Blocking it lowers uric acid in blood and urine, so over months the body's urate stores shrink and gout attacks become rarer. The same block slows the breakdown of azathioprine and mercaptopurine, raising their levels.
Uses
What is febuxostat used for?
- Chronic gout when allopurinol fails or is not tolerated
- High uric acid during chemotherapy for blood cancers (EU)
Side effects
Side effects of febuxostat
- Higher risk of death from heart causesKnown forSerious
- Abnormal liver tests and liver failureKnown forSerious
- Gout flares when treatment startsKnown for
- Nausea
- Joint pain
- Rash
- Dizziness
- Severe skin reactions (SJS, TEN, DRESS)Serious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Boxed warning: more cardiovascular deaths than with allopurinol in gout patients with heart disease; use only if allopurinol is unsuitable.
- Contraindicated with azathioprine or mercaptopurine, as it raises them to toxic levels.
- Check liver tests before starting; stop it if liver injury is confirmed with no other cause.
- Flares are common early; give an NSAID or colchicine alongside for up to six months.
Good to know: In the CARES trial in gout patients with heart disease, sudden cardiac death was the commonest cause of the extra cardiovascular deaths on febuxostat.
Remember it
A way to remember it
Xanthine oxidase inhibitors shut the uric acid factory; they don't open the drain.
They lower uric acid by cutting its production, unlike uricosuric drugs, which raise its loss in urine. As stores shrink, urate moves out of tissues, which is why flares rise at first.
Written for biofideX
Its class
Xanthine oxidase inhibitors
Other xanthine oxidase inhibitors with a card:
Easily mixed up with colchicine and non-steroidal anti-inflammatory drugs.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Febuxostat tablets: label (DailyMed)
- Febuxostat (NCI Thesaurus)
- Adenuric (febuxostat): EPAR summary (EMA)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Pain, fever and inflammation
Febuxostat is one of 15 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
Start Practicing