AbstractA double‐blind, controlled study was conducted to assess the effects of allopurinol on Duchenne muscular dystrophy. Six patients—three treated with allopurinol and three given a placebo—were followed up for one year and were evaluated by functional and manual muscle testing as well as by determination of serum creatine kinase (CK) levels. Patients in both the allopurinol‐treated group and the placebo group deteriorated at varying rates without evidence of therapeutic benefit. To exclude the possibility of error attributable to small sample size, all six patients were treated with allopurinol for an additional eight‐week period. Muscle strength continued to deteriorate during this phase of