Allopurinol Skin Reactions in Gout Might Predict Febuxostat Reactions
WASHINGTON, DC—Use of febuxostat (FBX) might cause skin reactions in some patients with gout who have experienced such reactions after allopurinol administration, according to research presented at the 2016 ACR/ARHP Annual Meeting.
“In our series, one out five patients with previous skin reactions to allopurinol also developed after FBX,” reported lead study author Neus Quilis, of the Section of Rheumatology, Hospital General Universitario de Alicante, in Alicante, Spain. “Larger studies are needed to confirm these results, but this finding strengths caution when using FBX in this subgroup of patients.”
Allopurinol is a leading urate-lowering agent in the treatment of gout, but in about 10% of patients, it is associated with potentially-severe intolerance, frequently manifesting as skin reactions.
Febuxostat (FBX) might be useful in treating allopurinol-intolerant patients but because these patients have been excluded from clinical trials, safety data has been limited. The research team therefore undertook a retrospective records review in order to determine skin reactions associated with FBX in these patients. Only patients with crystal-confirmed gout who had been treated with FBX were included. For patients with histories of allopurinol skin reactions, clinical, lab, and demographic data were collected, including age, sex, skin events, serum uric acid, glomerular filtration rate, and HLA-B*5801 status. Median age of patients was 68.5 years and 75% were male.
Of 102 patients with gout treated with FBX, 24 patients had experienced prior allopurinol-related skin events.
“Most used starting dose of FBX was 80mg/d (n=16), [and] others were 5mg/d (n=1), 40mg/d (n=4) or 120mg/d (n=3),” the team reported. Median glomerular filtration rate at that time was 77.2 mL/min (62.7–68.6).
“We identified five patients (20.8%; 95% CI: 3-38%) who also developed skin reactions with FBX,” they reported. Four cases involved nonspecific rash and one patient had Stevens-Johnson syndrome.
"They were HLA-B*5801 negative, and none of these patients presented skin reactions to benzbromarone,” the team reported.