The FDA has approved Merck’s Belsomra, a new type of sleeping pill for adults who have difficulty falling asleep and/or staying asleep.

The drug is the first sleep aid to work on receptors of the neurotransmitter orexin, which helps keep people awake. In three clinical trials involving some 500 patients, those taking Belsomra (suvorexant) fell asleep faster and spent less time awake during the night than patients on placebo.

The approval includes four dosage strengths — 5 mg, 10 mg, 15 mg and 20 mg — with the recommended dosage being 10 mg within 30 minutes of going to bed. Patients should only use Belsomra if they plan to sleep for at least seven hours, the FDA says. Maximum dosage per day is set at 20 mg.

The approval comes with a caution about unintended drowsiness. A separate study, conducted at the FDA’s request, found that both men and women who took a 20 mg dose of Belsomra experienced some driving impairment the following day.

The FDA has recommended that Belsomra be classified as Schedule IV, Merck says. A final decision by the Drug Enforcement Administration is expected later this year. The company plans to launch Belsomra in the U.S. late this year or in early 2015.

The green light comes approximately one year after the FDA expressed concern over higher doses of the drug and asked Merck to set the starting dose at 10 mg, with a 5 mg option for patients on other therapies that might interfere with Belsomra. At the time, Merck said it would likely have to perform a manufacturing study to assess its capability to produce a stable drug at 5 mg and 10 mg.

Merck spokeswoman Pam Eisele said that the company spent the last year completing those studies and resubmitted its application to the FDA this past February. — Lena Freund

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.