WASHINGTON (AP) -- A federal panel of medical experts said that an experimental insomnia drug from Merck & Co. Inc. appears safe and effective, despite evidence from company trials that the pill can cause daytime sleepiness and difficulty driving.
A majority of Food and Drug Administration panelists voted Wednesday that Merck's sleeping aid, suvorexant, helped patients get to sleep and stay asleep. In a separate set of votes, the panel voted that the drug appears safe at the starting doses proposed by the company.
The FDA is not required to follow the recommendations of its experts, though it often does.
The panel opinion was somewhat at odds with the agency's own scientists, who issued a negative review of the drug earlier in the day. FDA staff pointed out that suvorexant was associated with daytime drowsiness, driving difficulties and suicidal thinking in trials conducted by Merck.
"How much is it worth to try and make the drug safer? How many people are you willing to risk versus how much effort are you willing to make?" said Dr. Ronald Farkas, who presented the FDA's findings.
The FDA drew attention to five women, or roughly 5 percent of patients, who had to stop a supervised driving test because they were too sleepy to continue. In another case, a 59-year-old man reportedly fell asleep at a traffic light and later veered off the road while taking the drug.
The FDA suggested that a lower dose of 10 milligrams might be safer for patients than the higher doses proposed by Merck.
But a majority of panelists endorsed the safety of initial doses proposed by Merck: 15 milligrams or 20 milligrams a day for elderly patients or non-elderly patients, respectively. The panel backed their safety in a vote of 13-3, with one abstention.
"Start low and go slow is likely to be effective," said Dr. Matthew Rizzo of the University of Iowa. "I also think the safety profile of this drug is not any worse and likely better than the drugs we are already using."
Much the meeting's discussion focused on the shortcomings of sleeping pills already on the market, most of which are also associated with lingering drowsiness.
In January, the FDA required drugmakers of Ambien and similar sleeping pills to lower the doses of their medications, based on studies showing that the drugs remain in the bloodstream at levels high enough to interfere with driving.
The panel narrowly voted 8-7, with one abstention, against doses as high as 30 milligrams and 40 milligrams, saying they could exacerbate problems with drowsiness and narcolepsy.
"I think the risks are substantial and it seemed to go up with the higher dose," said Natalie Portis, the panel's patient representative.
Merck has suggested raising patients' prescriptions to the higher levels if they do not respond to lower doses.
If the FDA ultimately approves suvorexant, it will be the first in a new group of drugs that aid sleep by blocking chemical messengers that keep people awake.
A Merck spokeswoman said Wednesday the FDA is expected to issue a decision on suvorexant by mid-year. If approved the drug will have to be scheduled as a controlled substance by the Drug Enforcement Administration.
Shares of the Whitehouse Station, N.J., company fell 62 cents to close at $46.71.