NEW RESEARCH: Anti-smoking drug Champix joins the fight against alcoholism
Has the rich aroma of a co-worker’s coffee ever made you crave one yourself? Or even driven you to walk into Second Cup for a latte?
Imagine then how challenging it can be for abstinent addicts to resist their former drug — especially in places where they used to consume it.
Nadia Chaudhri, associate professor of psychology in Concordia’s Faculty of Arts and Science, is testing whether a medication widely used to help smokers quit could also assist recovering alcoholics. The drug in question is a compound called Varenicline, which is sold in Canada as Champix.
“Already, Varenicline’s effects have been shown to be transferrable to alcohol addiction, since heavy smokers who were also heavy drinkers often reduce consumption of both.”
Now, Chaudhri and her research team are going a step further to see if the drug can help recovering alcoholics resist the temptation of their old drinking environments. The study’s results were recently published in Neuropsychopharmacology.
To set up the experiment, Chaudhri and her team needed to get lab rats to drink lots of alcohol, take them through a recovery process and then tempt the abstinent animals to seek alcohol again.
To introduce environmental triggers to stimulate relapse they devised a system where rats learned about alcohol in a specific context, and went through the recovery process in a different context.
Rat rehab
Rats were first exposed to a solution of 15 per cent ethanol. They tried it out of curiosity and eventually became regular drinkers.
The rodents were then trained to associate an auditory signal with alcohol in a cage that was decorated with specific contextual stimuli, like a textured floor and a lemon smell. They received presentations of a tone followed by drops of alcohol. Eventually they learned that the tone predicted alcohol, and went in search of alcohol whenever the tone was played.
After this, a ‘rat rehab’ phase was initiated. The rats were placed into another environment with different smells and textures, and the tone was played without alcohol delivery, leading them to dry out. This mimics the process of withdrawal and rehabilitation that many human addicts experience.
The challenge for the rats came when they were returned to the context where they had learned to link the tone with alcohol. How would they resist looking for alcohol when exposed to the site of their former pleasures?
“It turns out they had greater success in doing so when aided by Varenicline,” says Chaudhri, who experimented with different doses of the drug to determine the minimum required to reduce the relapse effect.
In another experiment using the same methods, Chaudhri’s team trained rats to predict sucrose when a tone was presented. Sucrose is an example of a ‘natural’ non-drug reward. Again, Varenicline helped those rats resist relapse, but the effective dose was lower for alcohol than sucrose.
Another study focused on finding out where in the brain Varenicline acted to exert its effect on relapse. The research team injected Varenicline directly into specific brain areas before the relapse test.
They found that a midbrain area enriched in dopamine neurons that was predicted to be important was actually not involved. However, Varenicline injected into a forebrain area that is central for addiction prevented relapse.
Chaudhri says she hopes to continue experimenting with Varenicline and exploring its effects on relapse induced by other types of triggers, such as stress.
