Many smokers will say that their habit soothes them, even if they are trying to quit. Depression is one problem from which some smokers are seeking relief.
A new study sponsored by Pfizer suggests that one of its medicines may help depressed smokers to quit cigarettes without worsening either the depression or anxiety that often comes with quitting.
"Ask your doctor about ways to stop smoking."
The study's lead author was Robert Anthenelli, MD, a psychiatrist who directs the University of California at San Diego School of Medicine's Pacific Treatment and Research Center. He is also chief of staff for mental health at the Veterans Affairs San Diego Healthcare System.
For the study, which was done between March 2010 and June 2012, Anthenelli and his co-researchers enrolled 525 study participants from 8 countries who were smokers and had been medically treated for major depression. Study participants — aged 18 to 75 — smoked at least 10 cigarettes per day but expressed a desire to quit smoking altogether, the researchers wrote. On average, they had been smokers for roughly 27 years.
Of the 525 study participants, 256 were prescribed one milligram of varenicline twice a day for 12 weeks. The twice daily dosage was sometimes dropped to .5 milligrams for study participants suffering from the drug's side effects, which included nausea, headaches, irritability, sleeplessness, nightmares and panic attacks.
Following the same daily schedule, 269 study participants took a placebo pill containing no medicine.
During the final four weeks of the 12-week treatment, 35.9 percent of those who were prescribed varenicline quit smoking. During the same period, 15.6 percent of those assigned to take the placebo also quit smoking.
After the 12 weeks of treatment, researchers monitored the habits of study participants for 40 additional weeks. At the end of those 40 weeks, 20 percent of the varenicline group had not started smoking again. Of the placebo group, 10 percent had managed to abstain from smoking.
Steve Leuck, PharmD, a Santa Cruz, CA pharmacist and president of AudibleRX, told dailyRX that it's important to note that Pfizer's Chantix has a US Food and Drug Administration "black box warning," explaining that the drug has serious side effects.
"They make the claim that this medication may be a potentially safe alternative for depressed patients who also need to quit smoking," Dr. Leuck said. "Varenicline [Chantix] has a black...package insert that states specifically to 'monitor for serious neuropsychiatric events including behavior change, hostility, agitation, depression and suicidality as well as a worsening of preexisting psychiatric illness'.”
Dr. Leuck added that while medications are used to help smokers quit, they may not automatically bring long-term success.
He said smoking cessation is a complicated issue: "In my experience, insurance companies are reluctant to pay for smoking cessation medications unless a patient is also enrolled in a smoking cessation support/education program. Most medication treatments work well to help a patient initially stop smoking; however, after the first 12 weeks, the medication treatment cycle is complete, and the individual needs to understand how to continue their life without smoking...Patients need to also understand that in order for their chances to be increased, they should also be enrolled in a smoking cessation course. "
For their part, study researchers concluded that depression did not worsen in those who quit smoking. They found no significant differences in mood, anxiety or thoughts about suicide were shown between the group taking varenicline and the one taking placebos. They did note that 6 percent of study participants taking varenicline and 7.5 percent of those taking the placebo had suicidal thoughts or showed suicidal behavior during the study.
"[O]ur findings suggest that varenicline may be suitable for smoking cessation in smokers with stably treated current or past depression. With 350 million individuals having the disease worldwide...and because a large proportion of smokers that seeks treatment has a lifetime history of [major depression], these results have the potential to reduce [sickness and premature death] in many smokers," researchers wrote.
Dr. Anthenelli added: "[S]tudies testing smoking cessation drugs generally exclude participants who are taking antidepressants, and relapse rates are high among those who do manage to quit. While this study didn't look at smokers with untreated depression, this drug may improve efforts by depressed smokers to quit and to maintain abstinence from tobacco use."
Not everyone completed the study. Seventy-seven varenicline participants dropped out either during treatment or the follow-up phase. From the placebo group, 90 participants dropped out.
Two people died during the follow-up phase of the study, though researchers say their investigation showed the deaths were not treatment-related.
The study was published online September 17 in the Annals of Internal Medicine.
Dr. Anthenelli is a scientific advisor to Pfizer. Instead of paying the researcher personal income, Pfizer funds some of his studies and other university activities. Pfizer was involved with this study's design and with how the data were collected, analyzed and interpreted.