Ambien, also known as zolpidem, is a prescription medication used for the short-term treatment of insomnia. The patent on zolpidem is held by Sanofi-Aventis, a Frenh pharmaceutical firm. Ambien has been known to cause a variety of side effects, including sleepwalking, hallucinations, delusions, impairment of motor coordination, and anterograde amnesia. In some cases, people taking Ambien have been known to drive while in a sleepwalking state and cause accidents without any memory of what happened. In a recent, highly publicized case, a U.S. Congressman wrecked his car after having taken Ambien and claimed to have no recollection of the accident. There are also reports of patients on Ambien binge eating in their sleep, leading to excessive weight gain.