Use of phenylbutazone in sports medicine: understanding the risks.

Despite the widespread use of phenylbutazone, its safety is still a controversial issue. One example of its toxicity is the fact that phenylbutazone has now replaced chloramphenicol as the most common cause of fatal drug-related aplastic anemia. To evaluate the toxicity of phenylbutazone as it is commonly used in sports medicine, a group of 3,000 healthy young athletes was studied following 1-week courses of phenylbutazone for various sports-related inflammatory problems. No serious adverse reactions were encountered. Four percent of the patients experienced mild gastrointestinal disturbances with less than 1% of the patients being forced to discontinue the medication. Compiling the results of other studies, it is estimated that the risk of a serious reaction to phenylbutazone is less than 1 per 100,000 when the drug is used by healthy young individuals for periods of 1 week or less. This risk increases significantly in older patients and with longer periods of treatment. Although phenylbutazone is widely prescribed in sports medicine, there appears to be insufficient information regarding its possible effects on athletic performance. Its capacity to cause significant fluid retention with secondary dilutional anemis, for example, could, in certain instances, have an adverse effect on overall performance if the drug is continued after the athlete returns to competition. Further study in this area is urged.