Investigating gender differences for effectiveness and side effects of varenicline during smoking cessation treatment

Varenicline is a useful pharmacological option for smoking cessation. Unfortunately, there is a lack of studies on its effectiveness, retention, and side effects in low- and middle-income countries. The present study aimed to investigate gender differences regarding these outcomes in a Brazilian clinical sample (n = 124). The 12-week treatment protocol included six consultations with a psychiatrist and six sessions of cognitive-behavioral therapy. All subjects received varenicline on the first evaluation, following the standard posology for 12 weeks and instructions to stop smoking after the second week of treatment. Both Mini-International Neuropsychiatric Interview (MINI) Plus and Fagerstrom Test for Nicotine Dependence were applied at baseline. The UKU-Side Effects Rating Scale was administered at weeks 3, 7, and 11, and the Questionnaire of Smoking Urges-Brief at weeks 1, 5, and 9 to ascertain the side effects of the medication and craving, respectively. At the end of the 12-week treatment, abstinence was biochemically assessed. At months 6 and 12 after the treatment, follow-up telephone interviews were conducted to access nicotine abstinence. Short- and long-term abstinence and retention rates did not differ between genders. However, women presented more side effects than men, especially in the second half of the treatment. Increased dream activity, reduced duration of sleep, constipation, and weight loss were the most notable side effects. Despite women reporting more side effects than men, this difference did not influence the treatment success rates.