A new study funded by the National Institutes of Health (NIH) suggests that a common over-the-counter supplement can reduce the cravings associated with chronic cocaine use. This research, released at the American College of Neuropsychopharmacology's (ACNP) annual conference is among the first to identify N-acetylcysteine (NAC) as a potential agent to modulate the effects of cocaine addiction. There is also early evidence in animal models of addiction to suggest that this chemical works similarly in the treatment of heroin addiction, and possibly alcoholism.

NAC is available over the counter as a supplement known for its antioxidant effects. Antioxidants are agents that clean up damaging free radicals in the body and are therefore thought to slow down the aging process of cells. The research was conducted specifically on because of its known metabolic pathway in the brain – affecting one of the same proteins as cocaine use.

"Cocaine is highly addictive and can have devastating effects on the health and well being of users," says lead researcher Peter Kalivas, Ph.D., Professor and Chair of the Department of Neurosciences at the Medical University of South Carolina (MUSC). "The discovery that a readily available herbal supplement can reduce the intense cravings associated with cocaine use is an important finding for individuals undergoing treatment for cocaine addiction. Reduced craving might help addicted individuals restrain from abusing cocaine."

In the first phase of the study, Dr. Kalivas and the research team conditioned rats on a regimen of cocaine to establish their addiction. The rats in the treatment group were then treated with NAC. After treatment, the cocaine-addicted rats exposed to NAC were significantly less likely to seek out cocaine than those without NAC. Those treated with NAC ceased to actively seek cocaine, but showed normal food-seeking behaviors.

In the second phase of the study headed by Drs. Robert Malcolm, Hugh Myrick, Steve LaRowe, and Pascale Mardikian in the Department of Psychiatry at MUSC, NAC treatment was investigated in a small inpatient study (n=15) involving non-treatment seeking cocaine-dependent subjects. In this phase of research, subjects were asked to look at pictures that were either neutral (e.g., trees, boats) or cocaine-related (e.g., drug paraphernalia). Those individuals treated with NAC reported less craving for cocaine and spent less time looking at the cocaine-related pictures. In addition, when using a functional magnetic resonance imaging (fMRI) test, subjects treated with NAC had reduced brain activity in the prefrontal cortex, the area of the brain activated during cocaine craving and used to modulate the addictive behavior of chronic cocaine use. An open label trial, which was recently completed, indicated that cocaine-dependent patients could take NAC on an extended outpatient basis, with minimal side effects. More importantly, patients taking higher doses of NAC were more likely to complete the trial, providing further indication of the potential benefits of NAC.

"The potential to use NAC for the treatment of individuals addicted to cocaine is a major finding," emphasized Dr. Kalivas. "For those individuals who have the desire to end their addictive habit, a NAC supplement might help to control their cravings."

A larger clinical trial that will follow 282 cocaine-dependent individuals has just begun in order to further understand and corroborate how NAC works in the brain to reduce cocaine craving. Dr. Kalivas stresses that while the initial findings are very promising, the widespread use of NAC in cocaine treatment is not advised until larger scale studies are complete.

In addition to its antioxidant properties, NAC is currently used in a variety of other ways: to counteract the effects of an overdose of acetaminophen (i.e., Tylenol®), to break up mucus in respiratory ailments, to lessen the symptoms of colds or the flu, and even to reduce the effects of hangovers. It is important to note that over-the-counter NAC may not be produced in the same manner as the prescription version used in this study, and that all herbal supplements should be used in moderation.

Cocaine is an illegal drug that acts as a powerful stimulant in the body. There are approximately 1.5 million Americans dependent on or abusing cocaine (i.e., chronic users). In addition, 2.7 percent of the general U.S. population has tried cocaine during their lifetime. Adults aged 18 to 25, particularly men, have the highest rates of cocaine use.

###