Zopiclone
Zopiclone was developed and first introduced in 1986 by Rhône-Poulenc S.A., now part of Sanofi-Aventis, the main worldwide manufacturer. Initially, it was promoted as an improvement on benzodiazepines, but a recent meta-analysis found it was no better than benzodiazepines in any of the aspects assessed. On April 4, 2005, the U.S. Drug Enforcement Administration listed zopiclone under schedule IV, due to evidence that the drug has addictive properties similar to benzodiazepines.
Cinchophen
Cinchophen was first introduced in 1908 as 'Atophan' and used for the treatment of gout and arthritis. It was efficacious at reducing the buildup of uric acid and became a popular medicine. Further studies in 1911 and 1912 were successful in isolating metabolites of cinchophen from human urine. During the 1920s, cases of severe adverse effects such as liver damage and cirrhosis had been clinically observed; the first case of jaundice was recorded in 1923 and the first fatality occurred in 1925. Approximately half of all patients experienced toxic effects and by 1932 there were 32 drugs available that contained cinchophen or its derivatives as their active ingredients , experiments were conducted to determine the drugs pharmacology but the mechanism of drug induced liver injury remained unclear. Cinchophen was considered to be too dangerous for human use in most countries but has applications in veterinary medicine as a treatment for osteoarthritis in dogs.