The next issue of The Medical Letter (1408; January 21, 2013) leads off with an article on new FDA requirements for lower doses of Ambien and other brands of zolpidem. The FDA was concerned particularly about the persistence of high blood levels of zolpidem into the morning hours, which could make driving unsafe. Our article pointed out that impaired driving performance is not the only problem that could occur with these drugs.
Zolpidem is a benzodiazepine receptor agonist, like zaleplon (Sonata) and eszopiclone (Lunesta). Functionally these drugs are virtually identical to benzodiazepines like Valium, Librium and Halcion, and all of them seem to have a similar potential for side effects. The media became enthralled for a time with reports that some people who took these drugs to sleep did some peculiar things in the night, including having sex, that they were unaware of in the morning. These reports did not make it clear whether the behavior was really uncharacteristic of the individual, or whether it was just the inability to remember it that was extraordinary.
The inability to remember something that happened after taking a drug is called anterograde amnesia, and when we first wrote about it years ago, two of our consultants, both famous names in academic psychiatry, told me about their own experience with this phenomenon, and it was so odd that I have never forgotten it.
The first man, whom I will call D., told me that one day after work he went to an obligatory faculty reception, which lasted longer than he would have liked, and drank 1 or 2 more cocktails than he should have. He arrived home late and, remembering that he had an early morning appointment, took a short-acting benzodiazepine to get to sleep. The next day as D. was driving home after work, he suddenly remembered, with the usual curse, that he was supposed to have gone to the dentist that afternoon. But then he quickly realized that he had an ache in his jaw that felt like the residual pain of a dental procedure. He had gone to the dentist, but he had absolutely no memory of doing so.
The second professor, whom I will call R., took a plane overnight to London, where he was scheduled to give a talk the next day. Flying in business class through the generosity of his English hosts, he had several cocktails and perhaps a glass or 2 of wine with his dinner. Then he took a benzodiazepine in order to get at least a few hours of sleep before landing. He met his hosts and gave his talk, which was well received. When the applause died down, R. realized that he had no idea what had happened to his luggage. To his great surprise, when he returned to his hotel, he found the luggage and learned that he had brought it there himself before proceeding to the auditorium. He had no memory of having done that.
So, sleeping-pill-taker, beware. If it could happen to them, it could happen to you. And if you must take a drug to get to sleep, skip that second glass of wine.