Allopurinol Hypersensitivity Syndrome: A Case Report and Review

Abstract

INTRODUCTION

Allopurinol, an analogue of hypoxanthine, is widely used in the treatment of primary and secondary hyperuricemia. The drug is generally well tolerated, with a low prevalence of adverse effects. Allopurinol hypersensitivity syndrome is a rare but life-threatening adverse effect of allopurinol therapy. Although the prevalence of this syndrome is thought to be low, more than 100 cases have been reported since 1970.1,2 Patients in hospital are at greater risk for allopurinol hypersensitivity syndrome because they often have poor renal function. The Boston Collaborative Drug Surveillance Program reported that 3.5% of a sample of hospital patients experienced an adverse effect attributed to allopurinol.3 Early recognition of this syndrome can result in significant reduction of morbidity and mortality associated with allopurinol use.