Merck Insomnia Drug Could Interfere with Driving the Morning After

New concerns have risen up regarding an experimental insomnia drug from Merck. The drug, which is commonly used to help patients fall asleep, may carry worrisome side effects, including daytime drowsiness and suicidal thinking.

The Food and Drug Administration released its review of the company's sleep aid, suvorexant, ahead of a public meeting on Wednesday. The pill works by temporarily blocking chemical messengers that keep people awake.

The FDA said company trials show suvorexant was better than placebo at helping people fall asleep and stay asleep. Regulators said Monday the drug's effectiveness was consistent across several doses tested by Merck & Co.

However, patients taking the highest dose of the drug experienced an eight-fold increase in daytime drowsiness, which could ultimately interfere with their abilities to operate a car in the morning. Suvorexant was also associated with increased risk of suicidal thinking.

According to The Huffington Post, those taking 20 milligrams and 40 milligrams of suvorexant had trouble staying in their driving lanes when tested by company researchers, and the FDA even states that four women actually had to stop the driving test due to excessive sleepiness.

To add to that, suicidal thinking is an added risk when taking the medication. Over 12 months, there were eight cases of suicidal thinking or behavior reported among patients taking the drug, compared with no cases among patients given the placebo. 

Health researchers are hoping that the dose can be lowered for various patients, with 15 milligrams for seniors and 20 milligrams for non-seniors. Doctors would gradually raise these doses to 30 milligrams and 40 milligrams, respectively, or until the patient's insomnia has been successfully treated.

"Indeed, if a dosage strength lower than 15 milligrams is unavailable, we would need to consider if the drug could be marketed safely at all, if we believe that a substantial proportion of the indicated population needs a lower dose," the agency states, according to its review.

In January, the FDA required drugmakers of Ambien and similar sleeping pills to lower the dosage of their drugs, based on studies suggesting a link to drowsiness-related injuries. The agency cited research showing that the drugs remain in the bloodstream at levels high enough to interfere with driving.