TUESDAY, March 17 (HealthDay News) -- Modafinil, a drug used to treat narcolepsy and psychiatric disorders, increases dopamine in the brain and may have the potential for abuse and addiction, according to a report published in the March 18 issue of the Journal of the American Medical Association.
Nora D. Volkow, M.D., from the National Institute on Drug Abuse in Bethesda, Md., and colleagues performed positron emission tomography in 10 healthy males using radioligands to measure extracellular dopamine (raclopride) and dopamine transporter availability (cocaine) after treatment with placebo and modafinil (200 mg or 400 mg).
After modafinil treatment, the researchers found that mean binding of raclopride was reduced by 6.1 percent in the caudate, by 6.7 percent in the putamen and by 19.4 percent in the nucleus accumbens, indicating that extracellular dopamine increased. In addition, mean cocaine binding decreased by 53.8 percent in the caudate, by 47.2 percent in the putamen and by 39.3 percent in the nucleus accumbens, indicating that dopamine transporters were blocked.
"In this pilot study, modafinil acutely increased dopamine levels and blocked dopamine transporters in the human brain," Volkow and colleagues conclude. "Because drugs that increase dopamine have the potential for abuse, and considering the increasing use of modafinil for multiple purposes, these results suggest that risk for addiction in vulnerable persons merits heightened awareness."
Abstract
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