Smoking Cessation Medicines Trigger Suicidal Behavior and Depression

Anti-tobacco extremists say that safer tobacco products aren’t necessary because FDA-approved medicines are effective. They ignore scientific evidence of those medicines’ paltry success rate (pharmaceutical nicotine works for only 7% of smokers), and of their significant side effects. For example, varenicline (Chantix) and bupropion (Zyban) carry FDA black-box warnings concerning depression and suicidal or self-injurious behavior.

A study published in PLoS One (here) concludes that “Varenicline shows a substantial, statistically significant increased risk of reported depression and suicidal/self-injurious behavior. Bupropion for smoking cessation had smaller increased risks.” The study’s first author is Thomas Moore from the Institute for Safe Medication Practices; his coauthors are from medical schools at Wake Forest, Harvard and Johns Hopkins Universities.

Moore et al. looked at cases of depression or suicidal/self-injurious behavior in the FDA Adverse Event Reporting System from 1998 to 2010. As a negative control for short-term medication, they compared behavioral episodes during varenicline and bupropion use to those during use of three common antibiotics. Because quitting smoking has also been associated with behavioral problems, Moore also used pharmaceutical nicotine as a “cessation” control.

Compared with antibiotic use, varenicline users were 37 times more likely to experience depression or suicidal/self-injurious behavior (odds ratio, OR = 37, confidence interval, CI = 28-49). The OR for bupropion was 13 (CI = 9-17), and the OR for nicotine was 4.3 (CI = 3.1-6.2).

Compared with nicotine (which controlled for behavioral problems due to quitting smoking), the OR for varenicline was 8.4 (CI = 6.8-10.4) and the OR for bupropion was 2.9 (CI = 2.3-3.7).

Moore also discussed other safety concerns: “While suicidal/self-injurious behavior and depression appear to be prominent side effects of varenicline, they are by no means the only safety issues. Varenicline has been associated with aggression and violence in three studies and carries a warning about this behavior. Its effect on vision, cognition, and motor control and other risks have led to its being banned for airline pilots, air controllers, military pilots and missile crews, and restricted for truck drivers. Varenicline is also associated with an increase in the risk of serious cardiovascular events. In addition, it is associated with hypersensitivity, angioedema and potentially life-threatening severe cutaneous adverse events [references omitted].”

Moore warns doctors prescribing varenicline about “…the value judgment of how to weigh the possible benefits of 52 weeks of smoking abstinence for 1 or 2 out of every 10 patients treated against the risk of less frequent adverse events such as violent and suicidal behavior that can have immediate, catastrophic and irreversible effects on self, family, and career. In the meantime, safer alternatives now exist and should be preferred.”

Unwritten is that one of those safer alternatives is smoke-free tobacco. While no tobacco product is absolutely safe, smoke-free alternatives deliver satisfying doses of nicotine, which is an important modulator of mood, well-being, and other behavioral performance measures.

Quit-Smoking Medicines and Episodes of Violence

A new study published in Public Library of Science One (available here) reports that two drugs widely prescribed to help smokers quit -- varenicline (brand name Chantix) and bupropion (brand names Wellbutrin and Zyban) - are associated with thoughts or acts of violence towards others.

The study was conducted by Thomas Moore at the Institute for Safe Medication Practices, and colleagues from Harvard and Wake Forest Universities. Moore et. al. analyzed data from the FDA Adverse Event Reporting System, extracting all serious adverse event reports for drugs with 200 or more cases received from 2004 through September 2009. The researchers focused on homicide, homicidal ideation, physical assault, physical abuse and violence related symptoms. They reported the number of events, as well as proportional reporting ratios (PRRs), which allows for comparison of the proportion of violence events for each medicine with the proportion from all other evaluable drugs (those in wide clinical use with adequate post-marketing surveillance).

Moore found that “among 484 evaluable drugs, 31 drugs met the study criteria for
a disproportionate association with violence, and accounted for 1527/1937 (79%) of the violence cases…Varenicline has the largest number of reported violence cases (n = 408), [and] the highest proportion of violence cases (PRR= 18.0).”

The PRR for varenicline was so high that it was in a class all by itself. As Moore and colleagues noted, “We have previously examined varenicline’s association with serious psychiatric symptoms including aggression/violence [references omitted]. The aggression/violence case series for varenicline was consistent with these data but revealed other features that may or may not occur in cases attributed to other drugs. These features include early onset of psychiatric symptoms (usually within a few days), a senseless act of aggression/violence directed at anyone who happened to be near by, and resolution of the symptoms upon discontinuation.”

Moore also found that bupropion, an antidepressant prescribed to aid smoking cessation, was also associated with violence, although at a much lower rate (35 episodes, PRR = 3.9). As he and his associates note, “bupropion is indicated for both depression and as an aid to smoking cessation, so those results are not limited to the smoking cessation population.”

Moore also studied pharmaceutical nicotine, which was associated much less frequently with violent episodes (11 cases, PRR = 1.9).

Tobacco prohibitionists like the American Cancer Society often claim that tobacco harm reduction is unnecessary, since medicines represent the gold standard for smoking cessation. This study demonstrates that the gold standard is substantially tarnished. At a minimum, the Cancer Society should update its website discussion of smoking cessation (here). The current version promotes varenicline and bupropion, but fails to mention the drugs’ possible side effect of violent behavior.