Objective: To assess the current status on re-evaluation of marketed drug in China since the promulgation of drug law in 1985.
Methods: Review of literature on Chinese pharmaceutical abstract and CBMdisc from 1985 to 2001 year was done.
Results: 4029 papers and 855 marketed drugs from 1985 to 2001 were included. Drugs on anti-infection agent, cardiovascular system and digestive system were the main drugs being re-evaluated, with the proportions of 27.1%, 20.1% and 11.1% respectively. The amounts of both marketed drugs and literature were increasing year by year. The method used for re-evaluation were random and non-random clinical trial. 41.4% of all the samples had a sample size of 50 - 100 research subjects. There were 13 papers with more than 5000 samples. The level on evidence based literature was assessed. 44 papers were graded as first class, and 182 papers the second, 2466 papers the third and 1337 papers the fourth. The quality of literature was improved year by year.
Conclusion: The amount, quality as well as the sample size of literature being re-evaluated on marketed drug were increased from 1985 to 2001. However, the design and evaluation of those trials were not standardized.