FDA Says New Insomnia Drug Must be Available at Lower Doses Before Approval

The Food and Drug Administration has advised Merck Pharmaceuticals that suvorexant, the company’s investigational medication for the treatment of insomnia, is not approved at doses of 30 mg and 40 mg.

In a response to the company's drug approval request, the FDA advised the company in a "Complete Response Letter" that 10 mg should be the starting dose for most patients and must be available before suvorexant can be approved; 15 mg and 20 mg doses would be appropriate in patients in whom the 10 mg dose is well-tolerated but not effective, the agency said. (And for patients taking concomitant moderate CYP3A4 inhibitors, a 5 mg dose would be necessary.)

“We will evaluate the requests outlined in the Complete Response Letter, and expect thereafter to work expeditiously with the FDA to make suvorexant available as a new treatment option for patients suffering from insomnia,” said Roger M. Perlmutter, M.D., Ph.D., president, Merck Research Laboratories, in a statement on the company’s Web site.

An article in the New York Times yestreday about the FDA decision notes that the agency’s decision is similar to the findings in May of a federal advisory panel, which concluded that lower doses of the drug were safe and effective, but expressed concern that higher doses led to daytime drowsiness and other side effects. It is also in keeping with a recent decision by the FDA that women who take the sleep drug Ambien reduce their dosage by half, because of similar concerns about drowsiness.

For more on insomnia, see Psychiatric News here.

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