A recent analysis of more than 1,000 safety reports submitted to the Food and Drug Administration about the sleeping pill suvorexant (Belsomra), found that it was associated with side effects such as agitation, disturbed sleep, and next-day drowsiness—or that it simply didn't work at all. Those and other effects are listed in the FDA's approved drug label for suvorexant or were already found in clinical trials. But because suvorexant is the first of a new type of sleeping pill with limited evidence supporting its safety, Consumer Reports has been closely monitoring the effects of the drug in real-world conditions.

One way to do that is through adverse event reports, which come from consumers and healthcare professionals who volunteer information to the FDA. In addition, drug manufacturers are legally required to share any complaints they receive about a product with the agency.

All sleep medications, including suvorexant, carry a long list of potential side effects. Clinical trials of suvorexant showed that it had risks, such as next-day drowsiness, which are similar to those posed by older types of sleeping pills, including the prescription drugs zolpidem (Ambien and generic) and eszopiclone (Lunesta and generic).  

To obtain the copies of the adverse event reports associated with suvorexant, we filed a request under the Freedom of Information Act with the FDA. The quantity and substance of those reports prompted the nonprofit Institute of Safe Medication Practice (ISMP) to undertake a comprehensive analysis, published in their January 2016 issue of QuarterWatch. The report reveals that between February 2015, when suvorexant first hit the market, to the following July, the FDA received more than 1,000 reports that the drug didn’t work as expected or caused harm.

“That’s a substantial number of reports, given the relatively modest numbers of prescriptions written for Belsomra,” says Thomas J. Moore, senior scientist for drug safety and policy at the ISMP, lead author of the analysis, and a consultant to Consumer Reports Best Buy Drugs. In first six months of 2015, Americans filled only about 95,000 prescriptions for suvorexant compared to more than 18 million prescriptions for zolpidem (Ambien and generic) and about 1.5 million for eszopiclone (Lunesta and generic) according to the market research firm IMS Health. 

A spokesperson for Merck, the manufacturer of suvorexant, told us that the company is “vigilant in monitoring adverse event reports” and that the reports “flagged to-date outline events for which adequate warnings already exist in the prescribing information for physicians.” The company also pointed out that because adverse event reports might contain incomplete and unconfirmed information, it’s impossible to know for sure that the drug caused the reported side effects.

Our previous review of the evidence the FDA relied on when approving suvorexant revealed that the prescription drug didn't improve people's sleep much and posed safety concerns.Those findings led our medical experts to advise skipping suvorexant.

Complaints About Belsomra

When Moore and his colleagues analyzed the FDA reports, they found that the majority of complaints fell into four basic categories, with some people citing more than one problem. Surprisingly, complaints weren't linked to how much of the drug people took. Overall people taking a lower dose of suvorexant were just as likely to report a problem as those taking a higher dose.

People reported that suvorexant:

  • Didn’t work. Ineffectiveness was the number one complaint, cited on more than 40 percent of the reports.
  • Disturbed their sleep. Nearly one-third of complaints were about disrupted sleep, most commonly nightmares or night terrors, abnormal dreams, and hallucinations. A few people said that they walked in their sleep or experienced sleep paralysis—an inability to move or talk while falling asleep or awakening.
  • Made them less alert. About 28 percent of the reports said that the drug affected people the next day, making them feel drowsy, headachy, dizzy, “hung over,” or tired. A small group complained of memory problems or confusion. There were five reports of serious incidents that may have been linked to medication use, including falls, a head injury, and a car accident.
  • Had the opposite effect. About one out of five reports noted that rather than helping people sleep, the medication made them agitated, irritable, or nervous. Some people also reported neurological effects such as shakiness or heart problems such as palpitations and chest pains. 

Finally, prescribing information for suvorexant warns of an increased risk of depression or suicidal behavior. The ISMP analysis revealed two completed suicides, two attempted suicides, and 10 cases in which people said they thought about taking their own life.

A woman lies awake considering whether to take suvorexant

Short Track Record, Lingering Concerns

ISMP acknowledged that one of the limitations of studying adverse event reports is that the reported injury could possibly be caused by other factors. In addition, many side effects go unreported. And there’s no way to judge how frequently problems occurred in the entire population of people taking the suvorexant.

Still, those early reports on suvorexant are important, says Moore, because evidence on this sleeping pill from clinical studies is so limited. Before suvorexant was approved, only 160 people took it for a year or longer in clinical trials. And while the FDA approved the drug in dosage strengths ranging from 5 mg to 20 mg, the 10-mg dose was studied in only 62 patients; the 5-mg dose wasn’t formally studied at all.

Moore is also concerned that before suvorexant was approved, the drug was not studied in people taking other medications that affect the brain. He points out that more than 20 percent of Americans take a psychiatric drug such as an antidepressant, antipsychotic, mood stabilizer, stimulant for ADHD, or tranquilizer. However, studies of Belsomra excluded those patients.

Better Solutions for Sleeplessness

All sleep drugs, not just suvorexant, carry a risk of side effects according to Nathaniel Watson, M.D., co-director of the University of Washington Sleep Center in Seattle and president of the American Academy of Sleep Medicine. For that reason, a drug should never be the first thing you reach for to get some shut-eye. 

“Sleep medications can cover up symptoms and don’t always get at the root problem of what’s causing your insomnia,” says Watson. Instead he advises as a first step consulting with your doctor to rule out an underlying medical problem and discuss proven sleep habits—for example, keeping consistent bedtime and wake-up times; stopping caffeine by mid-afternoon; limiting alcohol; keeping your bedroom dark and quiet; and turning off your television and computers at least an hour or so before bedtime.

If that doesn’t solve the problem, ask your doctor for a referral to a professional who specializes in cognitive behavior therapy for insomnia. “That’s been shown to work just as well as medication—if not better—long term,” says Watson.

In general, Watson advises reserving sleep medications to treat insomnia related to short-term reasons—for example, jet lag, job loss, or the death of a loved one. And even then you should be cautious, following all labeled instructions regarding how much of the drug to take, when to take it, what it shouldn’t be combined with (alcohol for example), and how long you need to allow before driving or doing anything that requires you to be fully alert.

For treating short-term insomnia, the Consumer Reports Best Buy Drugs pick is the prescription drug zolpidem, the generic version of Ambien, which has a much longer track record than Belsomra and costs much less ($16 to $17 for 7 pills compared to $70 for 7 pills of Belsomra.) But as with all sleeping pills, results tend to be modest: our Best Buy Drugs Report found that people who took zolpidem fell asleep 20 minutes faster and slept 34 minutes longer on average than those who took a placebo.

Editor's Note: These materials were made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by a multistate settlement of consumer fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).