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

Pharmacological treatments for smoking cessation are effective and can increase quitting rates by 30%¹. However, women do not benefit from it as much as men do²,³; for them, to quit smoking can be as difficult as for low-income populations or people with severe mental illness⁴,⁵. Both sex (biological) and gender (cultural) differences may be responsible for these discrepancies. For example, women metabolize nicotine more quickly, which causes more severe withdrawal symptoms and less response to nicotine replacement therapy³. Fear of stigmatization and custody issues, especially if smoking during pregnancy or exposing children to second or thirdhand smoking, can be important barriers when seeking help⁶.

In addition, women have been excluded from clinical trials for many years due to the belief that biological differences or the need to care for their children would bias the results or prevent them from participating in studies⁶. Therefore, many treatment guidelines and public health policies have been developed based on studies that cannot be generalized to the female population⁷. Results from a recent meta-analysis have shown that varenicline is more effective in women and may help balance the differences in smoking cessation rate⁸. However, it is more expensive than bupropion and nicotine replacement therapy and is not currently available in the Brazilian public health care system⁷,⁹.

Nonetheless, economic implications due to these gender differences cannot be ignored. Smoking-attributable hospitalizations for former smokers are 70% lower in comparison to those who did not quit smoking, and this difference is larger for women aged 35 to 54 years¹⁰. In addition, health problems can be extended to the fetus or newborn, and the harmful effects of nicotine use during pregnancy and breastfeeding have been well described in the literature⁶.

Therefore, the work of Castellani et al.¹¹ makes some valuable contributions. First, it is in line with an international movement that encourages research on women and addiction for the reasons explained above⁶. Second, replicating findings of varenicline’s effectiveness among women in a Brazilian clinical sample may support the inclusion of the medication in treatment programs. For low- and middle-income countries, this is especially important since the rational use of financial resources is crucial. However, public health policies that aim to encompass women’s needs more effectively may assure equity and diminish the economic burden associated with tobacco use.

REFERENCES

• ¹
  Cahill K, Stevens S, Lancaster T. Pharmacological treatments for smoking cessation. JAMA. 2014;311(2):193-4.
• ²
  Smith PH, Kasza KA, Hyland A, Fong GT, Borland R, Brady K, et al. Gender differences in medication use and cigarette smoking cessation: results from the International Tobacco Control Four Country Survey. Nicotine Tob Res. 2015;17(4):463-72.
• ³
  Benowitz NL. Nicotine addiction. N Engl J Med. 2010;362(24):2295-303.
• ⁴
  Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. The NSDUH report: smoking and mental illness. Rockville: Center for Behavioral Health Statistics and Quality (CBHSQ), SAMHSA, and by RTI International in Research Triangle Park; 2013.
• ⁵
  Drope J, Liber AC, Cahn Z, Stoklosa M, Kennedy R, Douglas CE, et al. Who’s still smoking? Disparities in adult cigarette smoking prevalence in the United States. CA Cancer J Clin. 2018;68(2):106-15.
• ⁶
  Begley J. Substance use in women. Res Rep Ser. 2016;1:1-4.
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  BRASIL. Ministério da Saúde. Instituto Nacional de Câncer, Coordenação de Prevenção e Vigilância. Abordagem e tratamento do fumante: consenso. Brasília: Ministério da Saúde; 2001.
• ⁸
  McKee SA, Smith PH, Kaufman M, Mazure CM, Weinberger AH. Sex differences in varenicline efficacy for smoking cessation: a meta-analysis. Nicotine Tob Res. 2016;18(5):1002-11.
• ⁹
  Instituto Nacional do Câncer (INCA). Ministério da Saúde. Programa Nacional de Controle do Tabagismo. [Cited on 2019 Sep 25]. Available from: https://www.inca.gov.br/programa-nacional-de-controle-do-tabagismo/tratamento
  » https://www.inca.gov.br/programa-nacional-de-controle-do-tabagismo/tratamento
• ¹⁰
  Maciosek, MV, Xu X, Butani AL, Pechacek TF. Smoking-attributable medical expenditures by age, sex, and smoking status estimated using a relative risk approach. Prev Med. 2015;77:162-7.
• ¹¹
  Castellani V, Gonçalves PD, Castaldelli-Maia JM, Malbergier A. Investigating gender differences for effectiveness and side effects of varenicline during smoking cessation treatment. Rev Assoc Med Bras. 2020; 66(2): 146-152

Publication Dates

• Publication in this collection
  15 May 2020
• Date of issue
  Feb 2020