Opiate Blocker Helps Women Stop Smoking

CHICAGO, Oct. 9 -- The opiate blocker Depade (naltrexone), when added to behavioral therapy and nicotine patches, can help women quit smoking, researchers here found. But men gained no benefit.

In an ongoing clinical trial, Depade plus other smoking-cessation tools increased the quit rate among women by nearly 50%, and reduced the typical weight gain during the first month after quitting, reported Andrea King, Ph.D., of the University of Chicago, and colleagues, in the October issue of Nicotine & Tobacco Research.

"Women have historically had less success than men in giving up cigarettes," said Dr. King. "In this small study, naltrexone seems to have closed that gap."

Depade has a long track record as an aid in controlling opiate addictions and in reducing relapse rates among alcoholics, but studies of the agent's ability to curb nicotine craving have been mixed. The drug may also work only in certain subgroups, the authors noted.

To determine whether Depade give a boost to standard smoking-cessation treatments, the authors conducted a double-blind, placebo-controlled trial in 110 adult men and women. The patients were smokers recruited through local advertising.

All volunteers received one hour of behavioral counseling per week for six weeks, and four weeks of the nicotine patch, titrated to deliver nicotine at 21 mg for the first two weeks, 14 mg for the third week, and 7 mg for the fourth week.

The volunteers were also randomly assigned to either placebo or Depade starting at 25 mg daily for three days before the quit date. The Depade was then increased to 50 mg/day on the quit date and for the following eight weeks.

The investigators defined successful cessation as "not smoking even a puff daily for one week and not smoking even a puff at least one day in each of two consecutive weeks at any point in the trial."

Among the group as whole, there was no statistically significant difference in quit rates between those who had received Depade and those who didn't: 48% vs. 41% (P=0.5), respectively.

But when the data were broken down by gender, the authors found that Depade helped to bring women's quit rates up to par with those of men. In the placebo group, only 39% of women had successfully stopped smoking at eight weeks compared with 67% of men (P

They acknowledged that the study was only preliminary, and too small for an in-depth analysis of the relative contributions of withdrawal, craving, and weight gain to smoking cessation or failure.

There was also a relatively high recidivism rate: at 24 weeks of follow-up. Only a little more than one-third of both men and women in the Depade group had managed to stay smoke free.

The research was supported by the National Institute on Alcohol Abuse and Alcoholism and the National Cancer Institute.