News reports began to surface last week concerning a rather bizarre phenomenon referred to as Ã¢â‚¬Å“Ambien sleepwalkingÃ¢â‚¬Â in which people find themselves in a virtual Ã¢â‚¬Å“Twilight ZoneÃ¢â‚¬Â caused by overdoses of the sleep medication Ambien (zolbidem).
Although the data came from a small case study of the unusual effects of the drug on six drivers, it has caused quite a stir among healthcare professionals and people who use the drug to help them sleep.
Laura Liddicoat, supervisor of the toxicology section of the Wisconsin State Laboratory of Hygiene in Madison, presented her findings at the American Academy of Forensic Sciences meeting.
According to Liddicoat, drivers under the influence of unusually high doses of Ambien have crashed their cars and then had absolutely no memory of the accident. The sleeping pill apparently continued to impair drivers even after they have attempted to sleep off the effects.
The pattern involves taking the drug and not sleeping, or taking more than the recommended dose. Some drivers, for example, got up and drove in the middle of the night, while others, who planned to go to sleep as soon as they got home, took the drug before driving.
It appears that in these situations, the patients haven’t slept all of the drug out of their system and some had also taken Ambien along with other antidepressants. Alcohol was not involved in any of the six cases reviewed.
According to Liddicoat, a standard 10 mg dose of Ambien produces serum levels of 121 ng/mL (58 ng/mL to 272 ng/mL). After eight hours of sleep, that level should be close to zero. In the six reported cases, however, levels were as high as 1,000 ng/mL, and in one case 4,400 ng/mL.
The results of having high amounts of the sleeping pill in their bodies have produced a variety of strange effects on drivers, including: driving on the wrong side of the road; crashing into stationary objects; and suffering confusion, imbalance, and memory loss. Some patients had no idea why they were in the hospital or were being arrested.
Liddicoat described extreme mental and physical effects when driving within five hours of taking the drug. “Drugged driving cases have been steadily increasing over the last five years, and Ambien cases have mirrored this trend, reaching a peak of 45 cases a year in Wisconsin alone in 2003 and 2004.”
Tests on subjects the morning after taking a single dose 10 mg (5 mg in the elderly) right before bedtime revealed no significant residual effects on memory or actual driving. In large doses, and without ample sleep, however, Ambien patients displayed confusion or loss of memory.
Sanofi Aventis, the makers of Ambien, instructs patients to take the drug right before going to bed and only when they can devote a full eight hours to sleep. The company also cautions against operating heavy machinery or driving.
According to the New York Times, Sanofi Aventis maintains that “the drug’s record after 13 years of use in this country shows it is safe when taken as directed.” The company has provided the FDA with reports of people driving while sleep walking due to residual effects of the drug.
The six examples of impaired drivers Liddicoat presented are: (1) Driver taking 670 ng/mL while driving, reported to be “very out of it;” (2) Driver taking 500 ng/mL plus Celexa (citalopram) crashed into a parked car, bizarre behavior, couldn’t follow simple instructions; (3) Driver taking 820 ng/nL, poor comprehension, nearly fell over; (4) Driver taking 190 ng/mL plus other antidepressants driving southbound in northbound lane; (5) Driver taking 1,000 ng/mL plus Zoloft (sertraline) crashed into a truck; got drug online and continued to increase doses; (6) Driver taking 4,400 ng/mL drove on rim of flat tire, hit mailboxes, very confused.