BEIJING, Sept. 1 -- China's drug watchdog has suspended sales of methotrexate and cytarabin hydrochloride, two drugs often used to treat acute leukemia and rheumatoid arthritis, made by Shanghai Hualian Pharmaceutical Co., Ltd.The State Food and Drug Administration (SFDA) made the decision because the National Center for ADR Monitoring reported that the drugs had caused adverse reactions including difficulty in walking and retention of urine in some leukemia patients.Several children sufferers of leukemia in three hospitals of Guangxi Zhuang Autonomous Region and Shanghai felt pain in their legs and some had difficulty in walking after being injected with the methotrexate drug made by the Shanghai company in early July.According to WHO statistics, there have been more than 12,500 reports of adverse reactions to methotrexate world wide.