Narcolepsy drug Provigil has been found to have potential links to addiction, according to recent U.S. study conducted by drug abuse experts, Reuter’s reports.
Cephalon Inc.’s Provigil—generically known as modafinil and approved since 1999—is being used with increased frequency to enhance brain performance, said Reuters, but the narcolepsy drug can be addictive in some people using the drug for this off-label purpose. The study, conducted as a pilot on 10 healthy men—aged 23 to 46—taking Provigil at normal doses, revealed increases in dopamine levels that occurred in the part of the brain that is active when other abusive drugs are taken, noted Reuters. USA Today reported that the men were given either 200 milligrams of modafinil, which is the recommended daily dose prescribed for treating sleep disorders, or 400 milligrams.
According to USA Today, the chemical dopamine is a neurotransmitter that carries messages from nerve cells to other nerve cells or tissues. The chance for abuse increases when dopamine has been boosted.
Provigil was approved by the Food & Drug Administration for narcolepsy-related excess sleepiness, sleep apnea, and shift work disorder. But it is used off-label for weight loss, attention deficit hyperactivity disorder (ADHD), fatigue, and depression, said Reuters, noting that its 2008 sales exceeded $852 million. Recently a trend in Provigil off-label use has been seen on college campuses to improve cognitive performance, said Reuters. This “smart-drug” trend led Dr. Nora Volkow, director of the National Institute on Drug Abuse, to review Provigil, said Reuters “The main problems that we see,” Volkow told Reuters, “are not the people who are properly prescribed the medication, but individuals who may be misusing and abusing the medication.”
Late last year, Dr. Volkow said she found that surveys taken at college campuses revealed that drugs such as Provigil and Novartis’ Ritalin (methylphenidate) were being used not only by students, but by professors and other individuals because of the medication’s so-called “brain-boosting” properties, said Reuters. “The message for individuals who are taking this medication who want cognitive enhancement is that its use could result in very serious cognitive effects, including addiction,” noted Volkow. FiercePharma cited an earlier piece in Nature in which some scientists admitted Provigil use to increase productivity.
“It has the signature that it could potentially be addictive,” said Dr. Volkow, whose study appears in the Journal of the American Medical Association, reported Reuters, adding “Studies have shown consistently that all of the drugs of abuse … have a common effect of increasing dopamine in this area, in the nucleus accumbens … that is believed to be crucial for their reinforcing effect and ultimately their underlying potential for producing addiction,” warned Volkow in a telephone interview with Reuters. The team said the results called for more research.
Provigil was believed to be less likely to cause addiction over other stimulants because it was thought not to increase dopamine levels, said FiercePharma; however, the researchers, who used PET (positron emission tomography) scanning in their study, found Provigil does raise such levels. Volkow warned that such “smart drugs” have been known to spark brief psychotic episodes, adding that there is scant evidence pointing to improved cognition.