While You Were Sleeping
Blockbuster sleep drug Ambien has been hailed as a lifesaver, by women especially, who depend on it to conquer insomnia and jet lag. But its bizarre, sometimes tragic side effects raise alarming questions about the go-to-bedtime fix.
By Kai Falkenberg
Troubled and angered over what happened to her, Lindsey Schweigert consulted with a civil attorney and reported her incident to the FDA and to Anchen Pharmaceuticals, the maker of the generic Ambien that caused her to sleep-drive. But neither seemed particularly interested in her story. The FDA filed Schweigert's complaint in a database called MedWatch, which collects reports about serious drug side effects. But the database relies heavily on voluntary disclosure from physicians, pharmacists, patients, and drug companies. The system is poorly organized and riddled with misspellings, making it difficult for the agency to draw meaningful conclusions. (Ambien, for example, is entered under 442 different names, including Ambiennn.)
The MedWatch database includes 1,350 reports of sleepwalking, road traffic accidents, or impaired driving between January 2004 and September 2011 in which Ambien or Zolpidem is listed as the primary cause, according to data provider AdverseEvents. That may not sound like a lot when it comes to a drug prescribed more than 35 million times a year, but it's clearly the tip of a much larger problem: A U.S. Government Accountability Office investigation into FDA monitoring of drugs post-approval says the agency's database captures only an estimated 1 to 10 percent of all adverse reactions. And as researchers point out, because Ambien-induced sleep behaviors are accompanied by amnesia, it's even more likely that they're underreported. "It's widely known that the actual incidence of adverse reactions is far greater than the number of reports submitted to the FDA. So 1,350 reports represents thousands of incidents," says drug-safety expert Dr. Nicholas Tatonetti, assistant professor of biomedical informatics at Columbia University.
Last December, Dr. J. Steven Poceta, a renowned sleep disorders specialist based in La Jolla, California, published an influential report profiling more than a dozen clinical and legal cases of Ambien-induced sleep-driving. "It's really unfortunate that we can't predict who might be at risk for sleep-driving and what the underlying cause really is," says Poceta, who speculates that Ambien may relax muscles less than other sleep aids, leaving them engaged and able to move. And because Ambien doesn't address those emotional issues that cause insomnia, partially awake users may seek out alcohol or food to relieve their anxiety. (The latter may explain why a number of incidents, like Schweigert's, involved sleep-drivers en route to restaurants or supermarkets.)
Part of the problem, notes toxicologist Lindsay (an expert in the Bronson case), is that Ambien isn't just prescribed by sleep specialists, who may be more up-to-date on side effects and FDA advisories. It's given out by physicians of every stripe, from surgeons for post-op care to OB/GYNs for menopause. "These doctors often don't read the literature that comes with drugs that they've been prescribing [and] rely on drug salespeople to keep them educated," says Lindsay. "If you were to poll 20 doctors in a room and ask them if they know that sleep-driving is a side effect of Ambien, 99 percent would say no." Her solution: The FDA should elevate the drug to a Schedule II controlled substance, like Ritalin and Oxycontin, with restrictions on refills and phoned-in prescriptions. FDA spokeswoman Sandy Walsh says reviewing new data about Ambien is one of the agency's "highest priorities," yet asserts that "the vast majority of people who take these drugs, Ambien and Zolpidem included, take them without having any sleep-related behaviors."
But elsewhere around the world, regulators have taken a more aggressive stance. In 2008, Australia's drug approval agency issued a black-box warning for Zolpidem (marketed there under the name Stilnox) the strongest possible without withdrawing the drug from the market highlighting its link to potentially dangerous side effects. And in June, amid persistent reports of "potentially dangerous" Zolpidem-induced behaviors, the agency issued another advisory to physicians. Regulatory agencies in Taiwan and Japan have also issued warnings. The drugmaker Sanofi, in an official statement, insists: "When taken as prescribed, Ambien is a safe and effective treatment for insomnia" and notes that the medication guide cautions patients against driving after ingesting it. But what about folks who heed the warnings yet crawl out of bed while still asleep and get behind the wheel? Or those unlucky enough to be on the road with them?
To Schweigert, it's unconscionable. "I'm still in shock to this day that I was able to even function. Was I on autopilot? I don't even know." For months afterward, she suffered from debilitating depression, playing out the what-if scenarios in her head over and over again. What if I hadn't taken the Ambien? What if I'd killed someone? "I understand medications have side effects," she says, "but this is so much more than that."