November 29, 2012
A new drug for insomnia helped people get a little more sleep with few side effects, researchers report. Suvorexant acts in a different way than drugs now on the market. It targets the brain chemicals that help keep people awake. Other drugs affect the brain in a broader way. That's one reason for side effects, such as daytime sleepiness. The new study of suvorexant included 254 healthy adults with insomnia. People were randomly assigned to receive 1 of 4 doses of suvorexant. They took the drug for 4 weeks and placebo (fake) pills for another 4 weeks. They spent the first night of each treatment in a sleep lab. On their first day taking suvorexant, they slept about 5% to 13% longer than those who took the placebo. That equaled about 21 to 37 extra minutes of sleep. The average difference varied with the dose people were taking. There was still benefit 4 weeks later, but it was smaller. About 10% of people on higher doses had daytime sleepiness. The journal Neurology published the study online. HealthDay News wrote about it November 28.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Insomnia is one of the most common types of sleep problems. It affects about 1 in 3 Americans at least once in a while. More than 10% of Americans have problems functioning in the daytime as a result of insomnia.
Doctors commonly think about insomnia in terms of how long it lasts.
If you have transient or short-term insomnia, you usually know why. Typical reasons include the death of a loved one, nervousness about a coming event, jet lag or discomfort from an illness or injury.
Long-lasting insomnia, on the other hand, is most often learned through conditioning. After going through a few sleepless nights, some people learn to connect the bedroom with being awake. Taking steps to cope with lack of sleep -- napping, drinking coffee, having a nightcap or skipping exercise -- only makes the problem worse.
As insomnia persists, anxiety about it may grow more intense. This may lead to a vicious cycle. Fears about lack of sleep and the resulting problems may become the primary cause of the insomnia.
You can buy many sleep products, either over the counter or by prescription. Some help, but many don't. And often there are side effects. The most common is drowsiness that lasts well into the next morning.
So it's welcome news that a new sleep drug is being developed. The drug is called suvorexant. Researchers say it could be more effective and have fewer side effects than other drugs on the market.
The new drug acts differently than other sleep drugs. Almost all of these drugs affect multiple functions in the brain. Suvorexant appears to block only orexins. These are brain chemicals that promote wakefulness. In studies done so far, including the newest one, people taking the drug fell asleep sooner and woke up less during the night.
What Changes Can I Make Now?
The U.S. Food and Drug Administration (FDA) is reviewing the drug for possible approval. However, even if the drug is approved, I don't intend to prescribe it right away. We have heard great things about drugs in the past based on well done clinical studies. But before I am comfortable prescribing it, I will need to see a longer record of effectiveness and safety.
Before reaching for a sleep drug, some changes in your routine may help. Doctors call this good sleep hygiene.
What Can I Expect Looking to the Future?
This study and others suggest that suvorexant will likely be approved in the future. The timing will depend on whether there has been enough study of the drug in humans to satisfy the FDA.