Australian doctors have been warned about a popular insomnia drug after reports of strange sleepwalking episodes such as binge-eating or driving.
Zolpidem and bizarre sleep related effects:
Zolpidem (Stilnox) was marketed in Australia in late 2000 for the short term treatment of insomnia. It is structurally unrelated to the benzodiazepines, but has a similar pharmacological action. In 2002, ADRAC reviewed the first year of use and it was noted about 75% of the reports received described one or more neurological or psychiatric reactions, especially visual hallucinations, confusion, depression and amnesia. This pattern, which is not shared by other hypnotics, has continued with hallucinations (104 reports) and amnesia (62) now the most frequently reported effects. Reactions associated with sleeping or falling asleep have been described in half of all reports submitted. Of particular interest have been 16 reports of sleep walking, which describe inappropriate or strange automatic behaviour “while asleep”, including binge eating and house painting.
There have been isolated reports in the literature describing sleep walking, including an article in the popular magazine Time which mentioned the impending publication of a case series describing a few dozen people who, after taking zolpidem, developed uncontrollable urges to eat while asleep and did not remember the feeding binges when they awoke. A case series describing 5 patients taking zolpidem who experienced uncontrolled eating while asleep has previously been published.3 There are two reports to ADRAC that describe this situation. In one report, a patient put on 23 kg in weight over 7 months while taking zolpidem. It was only when she was discovered eating in front of an open refrigerator while asleep that the problem was resolved. In another report, a patient who had experienced significant weight gain was found by a relative taking food from the refrigerator and kitchen cupboards while asleep. Other reports to ADRAC describe a patient who woke with a paintbrush in her hand after painting the front door while asleep, a patient who walked around the house like a “mad man” while asleep, and two further reports which suggest the possibility of driving while asleep.
ADRAC recommends prescribers should be alert to the fact that zolpidem may be associated with distressing neurological or psychiatric reactions, including those associated with sleeping or falling asleep, and should warn their patients about the possibility of these untoward effects, particularly if they are going to take zolpidem for the first time.