A new drug can help cigarette smokers cut down gradually when they can't go cold turkey, according to a recent study.

Chantix, an anti-smoking medication, can boost the likelihood of smokers who aren't ready to stop cold turkey to cut back on cigarettes, HealthDay reported. It helps smokers quit or cut back on their nicotine habit by making cigarette smoking less satisfying.

"This allows us to reach a much broader population of smokers who aren't willing to quit abruptly or set a quit date, and it shows that people can quit without going cold turkey," lead study author Dr. Jon Ebbert, a professor in primary care and internal medicine at the Mayo Clinic in Rochester, Minnesota, told Reuters. "This is very strong support for changing clinical practice to include gradual reduction aided by medication."

For the study, researchers randomly assigned more than 1,500 smokers to take Chantix or a placebo over 24 weeks. All of the smokers were interested in cutting down but not prepared to quit cold turkey. Participants were asked to reduce cigarette use by 50 percent by the fourth week, and by 75 percent by the eight week, with the goal of quitting by week 12. By the last 10 weeks of treatment, weeks 15 to 24, the group taking the pill had significantly higher abstinence rates than the group on placebo.

Researchers found that this held true even after treatment stopped.

"This is the first study of its kind to enroll a group of smokers who are not traditionally enrolled in clinical trials because they are not ready to quit," Dr. Caryn Lerman, professor of psychiatry and deputy director of the Abramson Cancer Center at the University of Pennsylvania in Philadelphia, told Reuters. "It offers compelling evidence that gradual reduction should be considered to facilitate quitting."

However, even though the anti-smoking medication helped some "hard-to-reach" smokers, the majority of them still failed to quit, noted Lerman, who wasn't involved in the study. Other treatments, such as nicotine patches and gum, can also help some smokers cut back gradually, she said.

Previous studies have linked Chantix to serious side effects such as suicidal thoughts, insomnia and headaches.

The study, published in the American Medical Association's journal JAMA, excluded people with a history of major depressive or anxiety disorder, suicidal behavior, panic disorder, post-traumatic stress disorder, schizophrenia, or psychosis.