The drug ketamine can decrease alcohol consumption in male rats that previously had consumed high amounts of alcohol when given unrestricted access several times a week, according to a new study published in the journal eNeuro.
Ketamine reduces alcohol intake in high-alcohol male rats but increases it in low-alcohol female rats. Image credit: Mediengestalter.
Alcohol use disorder is one of the most prevalent forms of addiction yet effective treatment options are lacking.
Prior preclinical and clinical studies found that ketamine reduces alcohol use disorder symptoms in both rats and humans, but the drug was administered once, rather than over a more realistic treatment time period.
Ketamine is itself an addictive drug, so it is critical to examine how it affects patients over extended use.
“There are no perfect treatments for alcoholism. Many patients relapse within a year after treatment,” said Professor Mohamed Kabbaj, a researcher in the College of Medicine at Florida State University and senior author of the study.
“What makes ketamine interesting in our study is that it reduced alcohol intake, and the effect was long-lasting even after we stopped ketamine treatment.”
In the study, Professor Kabbaj and colleagues examined how ketamine affected the rats’ alcohol consumption and how that alcohol intake affected their self-administration of ketamine.
They divided male and female rats into groups based on how much alcohol they were prone to consume.
The rats were allowed unrestricted access to alcohol three times a week. Three weeks later, ketamine treatments began.
Ketamine administration reduced alcohol consumption in high-consumption male rats, and the effects lasted at least three weeks after the ketamine treatments ended.
Ketamine did not affect the habits of high-consumption female rats and increased drinking in low-consumption females.
The female rats also displayed a higher risk of abusing ketamine compared to the male rats.
“Three weeks is a long time in a rat’s life,” Professor Kabbaj said.
“If a similar thing happened in humans, one could imagine that after a short treatment with ketamine, alcoholic patients would cease alcohol intake for a couple of years. That would be a great achievement.”
“Clinical studies for men and for women are needed before ketamine is used as a therapy for alcoholism in either sex,” the researchers said.
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C.E. Strong et al. Sex and individual differences in alcohol intake are associated with differences in ketamine self-administration behaviors and nucleus accumbens dendritic spine density. eNeuro, published online November 18, 2019; doi: 10.1523/ENEURO.0221-19.2019
