"We now have an effective medication [for narcolepsy] with few side effects that's easy to prescribe and that's easy for the patients because they don't have to keep getting new prescriptions often," Gross says. Patients taking stimulants, such as amphetamines, to treat narcolepsy have to get new prescriptions filled frequently because this class of drugs is more tightly controlled by law and physicians can only prescribe a limited amount at a time.
After nine weeks of treatment, the drug was stopped for 80% of the patients to see how stopping the medication would affect them -- if it would affect them.
During the two weeks following drug discontinuation, patients complained of feeling more sleepy, but no signs of amphetamine withdrawal syndrome -- such as sadness, fatigue, vivid unpleasant dreams, sleep changes, and increased appetite -- were apparent. This suggests that the treated patients had not become dependent on the drug.
"This is a very important addition to our [arsenal] for narcolepsy," says Gross, who is director of the sleep disorders center at the Lahey Clinic in Burlington, Mass., and was the lead investigator of the U.S. Modafinil in Narcolepsy Multicenter Group.
"This study demonstrates that modafinil is very efficient for most patients with narcolepsy without any noticeable side effects," says Seiji Nishino, MD, PhD, who reviewed the study for WebMD. "Because it's easy to use, we should see good compliance, especially because it produces few side effects. I think it will make a big difference [in the treatment of people with narcolepsy]." Nishino is associate director of the Center for Narcolepsy at Stanford University.
Gross says it is important to realize that although modafinil improved alertness in a profoundly sleepy population, it did not completely resolve all symptoms of excessive daytime sedation. He also warns that improvements in sleepiness may not occur until about three hours after taking the medication.
Nishino is quick to point out that traditional treatments may still be useful for narcolepsy, "[So] if modafinil doesn't work, we can still use the classical stimulants."
This study was funded by a grant from Cephalon Inc., the manufacturer of modafinil.
- Narcolepsy is an underdiagnosed condition that affects one out of 2,000 people and is characterized by excessive daytime sleepiness, sudden attacks in which sufferers are unable to move their bodies and therefore fall down, attacks of paralysis while trying to sleep, and hallucinations.
- Researchers have found that the drug modafinil can help narcolepsy patients be less sleepy and stay awake longer with fewer negative side effects.
- Currently, stimulants such as amphetamines are used to treat narcolepsy, but these are difficult to prescribe because of legal restrictions on the drugs.