I thought it was a joke the first time I saw this mentioned in an ad
When taking Ambien CR don't drive or operate machinery.
Sleepwalking, eating or driving while not fully awake with memory loss for the event...
No one wants to turn people away from their product with scary warnings. So their warning don't always capture the reality of the situation. Like this one for Ambien CR.
It turns out that people taking Ambien and Ambien CR are sleepwalking, binge eating, and driving without being conscious of what they are doing. Besides Tiger Woods, how big a deal is that?
I could go into detail about how drugs are tested, side effects (known as "adverse reactions") are reported, etc., etc. But that would put you to sleep faster than Ambien. So I will skip that and say the process is complex. It is a lot safer than it used to be, but there is always room for improvement. It's been said that if aspirin were invented today it wouldn't get to market because of all the adverse reactions associated with it. There's a lot of truth to that.
It is not unusual to spend $10 million dollars on a large Stage III clinical trial that tests a drug's safety in humans. These commonly involve thousands of people (actually 3,660 people in the case of Ambien). The point is to look for "frequent", "infrequent" and "rare" adverse reactions. Rare adverse reactions occur < 1/1000 subjects. Frequent adverse reactions occur > 1/100 subjects.
Sometimes rare adverse reactions don't show up in clinical trials, even when you have a few thousand subjects. It is possible to have a statistical probability of showing up 1/1000 times without showing up in a sample of 3,000. The probability of getting heads when I flip a coin is 1/2. But I could flip the coin 3 times and get tails every time and that wouldn't strike anyone as bizarre.
However, when a drug goes to market a lot more people use it. If it is a blockbuster like Ambien, 30 million prescriptions a year get written. That's 10,000 times more people using it than were originally tested. If you have a rare event now, even if it is only 1/1000 times, you are going to see more examples of it. About 10,000 times more.
That brings us to driving while you are asleep.
It turns out people are reporting a bizarre adverse reaction with Ambien that you don't see with other sleeping pills. Technically, it's called somnambulance. That's sleepwalking. Sleepwalking raises a really interesting question about what exactly it means to be asleep, what is consciousness, etc. I'm not going to get in to that right now. Maybe next time. Let's just say, if you are totally unaware of what you are doing, you may as well be asleep.
Wandering around your apartment in your sleep might be embarrassing. Driving while you're asleep is extremely dangerous.
Here's the $3 billion question. How often is this happening? Short answer: we don't know yet. However, a growing number of reports suggest this is much more common for people taking Ambien than any other commonly used sleeping pills. People may want to dismiss those reports as "anecdotes", but the plural of anecdote is data.
Is there any really good data? Yes.
About 20 states take blood samples of drivers arrested for impaired driving when alcohol is ruled out as a contributing factor. Alcohol accounts for about one third to one half of all cases. The number one drug after alcohol is marijuana. In ten states, Ambien is in the top 10 of the drugs that show up in the bloodstream of impaired drivers that got arrested.