For almost a decade, the drug varenicline—marketed by Pfizer as Chantix—has been spotlighted as a pharmacotherapy intended to help smokers quit smoking. Now the drug is in the spotlight for a different reason—its ability to reduce alcohol use.
During APA’s 2015 annual meeting last month in Toronto, Daniel Falk, Ph.D., a health science administrator for the National Institute on Alcohol Abuse and Alcoholism (NIAAA), presented results from a phase 2 clinical trial that assessed the effectiveness and safety of varenicline in the treatment of alcohol use disorder.
“There is a high comorbidity between nicotine use and alcohol use,” said Falk, who explained to Psychiatric News that one-third of Americans who use nicotine also use alcohol.
Falk told Psychiatric News that he and his colleagues decided to study the off-label use of varenicline after the results of animal studies and small clinical trials found that the drug reduces alcohol craving and intake.
Since the launch of varenicline as Chantix, Pfizer, the drug manufacturer, has paid out more than $275 million to settle thousands of lawsuits claiming that the drug caused adverse psychiatric symptoms such as suicidal ideation. In 2009, a black-box warning for the drug was mandated by the Food and Drug Administration.
Falk and colleagues’ phase 2 trial included 200 adult smokers and nonsmokers with alcohol use disorder, in accordance with DSM-IV, who were administered 2 mg of varenicline daily or a placebo for 13 weeks. According to Falk, the study participants consisted mostly of males who had been engaging in frequent heavy drinking (five or more drinks a day) for an average of 20 years. The participants had no history of other drug use or psychiatric disorders.
The results showed that participants taking varenicline had an average of 33 percent fewer heavy drinking days over the course of the trial compared with the placebo group. In addition, the varenicline cohort was on average 13 percent more likely to abstain from daily alcohol use. Participants reported symptoms of nausea, constipation, and chest pains, but no psychiatric symptoms.
“The treatment worked well in both nonsmokers and smokers,” said Falk, who mentioned during his session presentation that smokers involved in the study were also able to reduce smoking as expected.
Falk hypothesized that the nicotinic acetylcholine receptor, which has been shown to be involved in the rewarding effects of both nicotine and alcohol use, may be responsible for this outcome. “We are definitely interested in doing more research with compounds that target the nicotinic acetylcholine receptor, like varenicline, in the treatment of alcohol use disorder, and we encourage other alcohol use disorder researchers to do the same.”
Falk informed Psychiatric News that, as far as he knows, Pfizer is not planning to market varenicline as a therapy to treat alcohol use disorder. ■
A video interview of Falk discussing varenicline’s use in the treatment of alcohol disorders can be viewed
here.
