In December 2015 the International Cricket Council (ICC) has reported an anti-doping rule violation against the Pakistan cricket player Yasir Shah after his sample tested positive for the prohibited substance Chlorthalidone. After notification a provisional suspension was ordered and the Athlete filed a statement in his defence. The Athlete gave a prompt admission and stated that the violation occurred without intention to enhance his sport performance or to mask the use of any other prohibited substance. He explained that both he and his wife suffered from high blood pressure and used different prescribed medication. In the morning before the match he was struck by hight blood pressure and by mistake under urgent and stressful circumstance he used his wife medication that contains Atenolol and Chlortalidone. The Athlete produced relevant medical information and showed the similarities to the blister packs containing the medications for him and his wife. Also he mentioned his medical condition and the use of his wife medication on the Doping Control Form. The ICC accepts the Athlete’s explanation how the substance entered his system under extreme and unique circumstances and concludes that he not intentionally acted with No Significant Fault or Negligence. Therefore the ICC decides on 7 February 2016 to impose a 3 month period of ineligibility on the Athlete starting on the date of the provisional suspension, . on 27 December 2016.
Valproic acid was first synthesized in 1882 by Beverly S. Burton as an analogue of valeric acid , found naturally in valerian .  Valproic acid is a carboxylic acid , a clear liquid at room temperature. For many decades, its only use was in laboratories as a "metabolically inert" solvent for organic compounds. In 1962, the French researcher Pierre Eymard serendipitously discovered the anticonvulsant properties of valproic acid while using it as a vehicle for a number of other compounds that were being screened for antiseizure activity. He found it prevented pentylenetetrazol -induced convulsions in laboratory rats .  It was approved as an antiepileptic drug in 1967 in France and has become the most widely prescribed antiepileptic drug worldwide.  Valproic acid has also been used for migraine prophylaxis and bipolar disorder. 
Typically, any athlete who tests positive for banned substances after having served a previous ban receives a lifetime ban from the sport of athletics. Many high-profile sportspeople to receive doping bans have come from the sport of athletics, with significant past cases concerning Ben Johnson , Marion Jones and Tim Montgomery . Furthermore, a number of athletes who underwent state-sponsored doping programmes in East Germany between the 1960s and 1980s were competitors in athletics, but the quality of the international anti-doping work was so poor that only one East German athlete ever tested positive.  Following allegations of state-sponsored doping in Russia , the IAAF suspended the country's athletes from competition, including the 2016 Summer Olympics.