OBJECTIVES : Allopurinol is the standard drug for urate-lowering management of gout and safe in most patients. It causes severe adverse reactions (Stevens-Johnson-syndrome) in Han-Chinese with genotype HLA-B*5801. Febuxostat is a new alternative to allopurinol does not carry significantly high risk of skin adverse reaction, was reimbursed by National Insurance since 2012 in Taiwan. This study aimed to evaluate the financial impact of ULT(uric-lowering therapy) after the reimbursement of febuxostat in Taiwan.

METHODS : We analyzed the claim data between 2009 and 2015 in National Health Insurance (NHI), a single payer in Taiwan with more than 98% national coverage. The trend of prescription claims and drug spending were analyzed of all the ULT, including febuxostat, allopurinol, benzbromarone, sulfinpyrazone and probenecid. We used SAS-EG for data processing and statistics. (Exchange rate 1 USD=31.42 NTD in 2015)

RESULTS : The overall ULT spending increased 5.21% from USD $8.25 million in 2009 to USD $ 8.68 million in 2011, and greatly increased 82.42% to USD $15.05 million in 2015.Of ULT spending, febuxostat spending gradually increased from 11.61% in 2013 to 49.19% in 2015, allopurinol (from 29.67% to 15.12 % ) and other ULT(from 58.72% to 35.69%) both declined. The number of patients treated with febuxostat continuously increased over time and accounted for 12.99% of all ULT users in 2015, whereas other ULT declined over time. The BIA predicted spending expansion was lower than the real-world usage.

CONCLUSIONS : The drug spending of ULT showed significantly increased following the Febuxostat introduction. Despite for substitution of allopurinol therapy as first-line therapy, febuxostat greatly expanded the entire class of ULT usage. These study findings highlight the needs to evaluate the cost-effectiveness of febuxostat use in clinical setting.