According to an analysis of prescription-medication claims from a large group of employers, the use of sleeping pills appears to have nearly tripled among people ages 18 to 24, rising from 599 users per 100,000 in 1998 to 1,524 users per 100,000 in 2006. The most popular sleeping pills were the non-benzodiazepine hypnotics Ambien CR (zolpidem) and Lunesta (Eszopiclone).