More research suggests that a single infusion of ketamine combined with counseling may help alcohol-dependent patients curb their drinking.
In a pilot study of 40 participants, those who were randomly assigned to receive intravenous ketamine plus outpatient motivational enhancement therapy (MET) showed greater abstinence rates, longer time to relapse, and fewer heavy drinking days than did those who received MET plus midazolam.
The findings support a U.K. study published late last year showing that a single dose of intravenous ketamine plus therapy that focused on reactivating drinking-related “maladaptive reward memories” reduced drinking urges and alcohol intake more than just ketamine or a placebo infusion alone ().
of the New York State Psychiatric Institute, Columbia University, New York, said in an interview.
“It’s an important area of research to understand in order to make behavioral treatments more effective, and ketamine appears to have the properties to address those vulnerabilities,” Dr. Dakwar said.
The study was published in the American Journal of Psychiatry (2019 Dec 2.
Pathologic alcohol use is responsible for an estimated 3.8% of all deaths globally, yet current interventions for alcohol use disorder have limited efficacy, the researchers noted.
New treatments with innovative mechanisms would be valuable, they added.
Ketamine is a high-affinity N-methyl-d-aspartate receptor (NMDAR) antagonist.
Previously, research offered “promising results” with the use of ketamine for cocaine use disorder, including increased motivation to quit and decreased craving, Dr. Dakwar noted.
“Those results led us to think about how ketamine might be helpful for other substance use disorders, especially given the overlap in clinical vulnerabilities and epidemiology,” he said.
The study from the U.K. researchers was conducted in 90 patients with harmful drinking behavior but who had not been diagnosed with alcohol use disorder.
Dr. Dakwar noted that this was “a nontreatment study. None of the people there had alcohol use disorder; they were heavy drinkers. Also, the effects there were fairly modest.
“My interest was how to integrate ketamine into a clinical, real-world framework that could be helpful for people,” he added.
The study included 40 participants (52.5% women; 70.3% white; mean age, 53 years) with alcohol dependence whose average consumption was five drinks per day.
All entered a 5-week outpatient program of MET, which involved engaging in strategies to promote motivation and self-directed change.
During the program’s second week, the participants were randomly assigned to received a 52-minute IV infusion of ketamine 0.71 mg/kg (n = 17) or the benzodiazepine midazolam 0.025 mg/kg (n = 23).
This ketamine dose was selected “because it was the highest dose tolerated by participants in preliminary studies,” the researchers reported.
“Midazolam was chosen as the active control because it alters consciousness without any known persistent ... effect on alcohol dependence,” they added.
The “timeline follow back method” was used to assess alcohol use after treatment. Abstinence was confirmed by measuring urine ethyl glucuronide levels with urine toxicology tests.
Other measures included use of a visual analogue scale, the Clinical Institute Withdrawal Assessment, and the modified Perceived Stress Scale.