China will build a comprehensive nationwide system to monitor adverse drug reactions in five years, an official from the country\'s drug watchdog said on Thursday. Adverse drug reactions (ADRs) refer to harmful and undesired effects that results from normal dosage of medicines, therapies or other kinds of interventions. Wu Zhen, deputy director general of the State Food and Drug Administration (SFDA), said at a national meeting on ADRs Thursday that China had already built a preliminary system to monitor ADRs at national, provincial and prefectural levels. He added that the current system will be perfected over the next five years, as committed institutions in different levels, related mechanisms and regulations will be established. The SFDA began to issue notifications of ADRs in 2005. It also has suspended the use of eight kinds of medicines based on the monitoring of ADRs, including Pergolide, Fenfluramine, and among others, which have potential risks to people\'s health.