American sprint hurdler Dawn Harper-Nelson, is serving a three-month ban after taking a prescribed medication which contained the banned substance hydrochlorothiazide. Harper-Nelson, who has won gold and silver medals at the Olympic Games in the 100m hurdles, tested positive for the banned diuretic and related metabolites on December 1, according to the U.S. Anti-Doping Agency. “Harper-Nelson’s explanation that her positive test was caused by a blood pressure medication she was prescribed by a physician to treat hypertension. Harper-Nelson further explained that she made efforts to determine if the medication contained prohibited substances; however, due to using partial search terms, those efforts were unsuccessful. The American’ suspension will expire on March 1, 2017 well ahead of all the major outdoor meets and this Summer’s World Championships in London.