Febuxostat Use During Breastfeeding

Introduction to Febuxostat and Breastfeeding

The British Association of Dermatologists recommends avoiding febuxostat during breastfeeding due to the absence of safety data and the known risk of severe drug interactions with azathioprine, which is commonly used in rheumatic conditions and is compatible with breastfeeding 1

The American College of Rheumatology implicitly recommends against the use of febuxostat during breastfeeding by suggesting alternative treatments, due to the lack of safety data and potential for severe drug interactions 2

Febuxostat, as a xanthine oxidase inhibitor, carries a substantially increased risk of life-threatening myelotoxicity when combined with azathioprine or other thiopurines, which is a critical concern for patients with rheumatic conditions 1
The British Association of Dermatologists explicitly warns that combined use of xanthine oxidase inhibitors (including febuxostat) with azathioprine requires strict monitoring and dose reduction, and should be considered experimental 1

The American College of Rheumatology recommends colchicine as a strongly compatible agent with breastfeeding for gout management, due to its established safety data in lactating women with rheumatic and musculoskeletal diseases 3
Colchicine is recommended as the preferred agent for gout management during breastfeeding, with NSAIDs conditionally recommended for acute gout flares 3

If treating gout during breastfeeding, the National Rheumatology Society recommends using colchicine as the first-line treatment, followed by short-term NSAIDs, and avoiding febuxostat due to lack of safety data 3, 2
If a patient is already on febuxostat and wishes to breastfeed, the British Association of Dermatologists recommends discontinuing febuxostat, switching to colchicine for gout management, and waiting until febuxostat is cleared from the maternal system before breastfeeding 1, 2, 3
If a patient is on concurrent azathioprine therapy, the British Association of Dermatologists recommends never combining febuxostat with azathioprine, continuing azathioprine, and using colchicine for gout management instead 1, 3

The relative infant dose (drug amount in breast milk divided by maternal dose, normalized per kg) should be <10% to be considered safe, according to the American Academy of Pediatrics 3
Febuxostat's lack of data during lactation means it falls into the category of drugs that should be avoided until further evidence is available, similar to other agents like leflunomide and mycophenolate, as recommended by the European League Against Rheumatism 2