Anti-Nicotine Drug Mecamylamine Could Help Alcoholics

Reduces Effects of Alcohol in New Study

Cigarette and Drink
Mecamylamine Can Help Smokers and Drinkers. © Getty Images

Researchers have discovered that mecamylamine reduces the self-reported stimulant and euphoric effects of alcohol in humans, and also decreases their desire to drink more.

Mecamylamine is a central nicotinic receptor antagonist that is believed to reduce the rewarding effects of cigarette smoking. Scientists have suspected for some time that common mechanisms may be involved in both nicotine and alcohol reward.

Furthermore, prior research has suggested that mecamylamine blocks the reinforcing effects of alcohol in animals.

Alcohol Produces Rewarding Effects

"Of all the drugs that act in the brain to produce their rewarding effects," said Harriet de Wit, associate professor in the department of psychiatry at the University of Chicago and corresponding author for the study, "alcohol has some of the most complex and varied effects on neurotransmitter receptor systems. One of the receptor systems where alcohol may act is the nicotinic acetylcholine (NACh) receptor system, the same system where nicotine acts.'

"By acting at these NACh receptors, alcohol also increases the activity of another neurotransmitter system, the dopamine system, which is where most drugs are thought to produce their rewarding effects. We hypothesized that mecamylamine would block the effects of alcohol on the NACh receptors which would, in turn, reduce the activity of the dopamine system, resulting in a dampening of the rewarding effects of the alcohol."

Measuring Alcohol's Effects

Researchers recruited 27 (14 males, 13 females) non-smoking social drinkers to participate in six laboratory sessions lasting roughly four hours each. At the beginning of each session, study subjects received either a placebo or one of two doses of mecamylamine (7.5 or 15 mg), followed two hours later by either an alcohol (0.8 g/kg) or a placebo beverage.

For two hours following beverage consumption, physiological and subjective-effect measures were taken at 30-minute intervals. The physiological measures included heart rate and blood pressure; subjective effects included stimulation and euphoria.

Mood-Altering Effects

"Our findings extend previous observations made in animals," said de Wit, "that alcohol produces its mood-altering effects, in part, through actions on the nicotinic receptor system. These findings also fit nicely with observations that alcohol users are often also smokers, and smokers tend to drink more than non-smokers. This suggests that these associations may have a biological basis, that is, they reflect shared actions on some of the same receptor systems."

Only one other published human study, by authors Ola Blomqvist and Henry Kranzler, has previously examined the effects of mecamylamine on subjective responses to alcohol. The present study expanded on their findings by testing another dose of mecamylamine, and by including a placebo beverage as a control condition.

Works For Heavy Drinkers?

"Clearly this study extends our findings," said Kranzler, a professor in the department of psychiatry at the University of Connecticut Health Center, "and provides another step in linking pre-clinical, animal findings with the effects of alcohol in humans. The study sample is also larger, which helps to validate our initial findings.

"It should be noted, however, that as with our study, the humans were healthy subjects, so additional work is needed to evaluate the clinical significance of these findings in heavy drinkers. It is likely, based on other research, that these effects can be extended to heavy drinkers."

Other than addiction disorders, mecamylamine has also been investigated as a treatment for neuropsychiatric disorders including major depression, Tourette's syndrome, schizophrenia and various cognitive and mood disorders.

Sources:

Chi, H. et al. "Mecamylamine Attenuates the Subjective Stimulant-Like Effects of Alcohol in Social Drinkers." Alcoholism: Clinical & Experimental Research May 2003

Bacher, L, et al. "Mecamylamine - a nicotinic acetylcholine receptor antagonist with potential for the treatment of neuropsychiatric disorders." Expert Opinion on Pharmacotherapy November 2009

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