Asthma Management Handbook

Asthma prevention and smoking

Recommendations

Advise women not to smoke while pregnant.

How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available).

Advise parents to ensure babies and children are not exposed to cigarette smoke (or to toxins from tobacco smoke that remain in clothing and hair).

How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available).

More information

Prenatal and childhood exposure to tobacco smoke

Tobacco smoking by pregnant women damages children’s respiratory health. It also increases the risk of stillbirth, spontaneous abortion, reduced foetal growth, preterm birth, low birth weight, placental abruption, sudden infant death, cleft palate, cleft lip and childhood cancers.1

Risk of developing asthma

Prenatal exposure to tobacco smoke and exposure during infancy increase the risk of wheezing during early childhood.2

Effects on children's asthma

Evidence from an Australian cohort study suggests that children with asthma whose mothers smoked during pregnancy benefit less from treatment with inhaled corticosteroids, and show less improvement in airway hyperresponsiveness over time, than those with asthma but no intrauterine exposure to smoke.3

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Electronic cigarettes (e-cigarettes)

Electronic cigarettes (e-cigarettes) are battery powered devices that create a mist, allowing people to simulate cigarette smoking. Most deliver nicotine in a vapour. Many also contain flavouring chemicals.

Safety concerns

E-cigarettes produce fewer toxins than conventional cigarettes, but there is very little evidence about their long-term safety,4 and effects on lung function are unclear.5

Concerns have been raised about the potential adverse effects on airway health:

  • In a small controlled study conducted among healthy smokers, short-term use of e-cigarettes was associated with increase in respiratory flow resistance, increase in impedance, and decrease in exhaled nitric oxide, compared with use of the device after removal of the cartridge containing the vapourisable liquid.6
  • Some e-cigarettes may contain potentially harmful chemicals such as propylene glycol (a respiratory irritant), formaldehyde, formaldehyde-forming hemiacetals, and potentially toxic particulate matter.578
  • A study reported that inhalation of e-cigarette solutions was associated with airway inflammation and airway hyperresponsiveness in a mouse model.9
  • An in vitro study reported that some constituents of liquid flavourings in e-cigarettes evoked a cellular physiological response in mouse tracheal epitheleal cells, which suggests that flavourings in e-cigarettes could harm airways.10
  • A study using a mouse model reported that neonatal exposure to e-cigarette emissions impaired lung growth.11

Very few studies have assessed potential benefits and harms in people with asthma. A small cohort study reported improvements in respiratory symptoms, lung function, airway hyperresponsiveness, and asthma control (measured by ACQ score) in people with asthma who switched from smoking conventional cigarettes to e-cigarettes.12

Positions and guidance by Australian organisations

The National Health and Medical Research Council (NHMRC) statement on e-cigarettes concludes: There is currently insufficient evidence to conclude whether e-cigarettes can benefit smokers in quitting, or about the extent of their potential harms. It is recommended that health authorities act to minimise harm until evidence of safety, quality and efficacy can be produced.7

NHMRC advises that studies show that e-cigarettes expose both users and bystanders to particulate matter (very small particles) that may worsen existing illnesses, or increase the risk of developing diseases such as cardiovascular or respiratory disease.7

Lung Foundation Australia recommends people quit smoking rather than try e-cigarettes.4

Quit Victoria warns that the short- and long-term health impacts of using e-cigarettes remain unknown, noting that e-cigarettes currently on the market have not passed through the extensive safety and efficacy evaluation required for products involving delivery of chemicals to the lung. Quit Victoria recommends that people use quitting aids approved by the Therapeutic Goods Administration, which have good safety profiles and have been shown to increase long-term quitting rates.13

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References

  1. Zwar N, Richmond R, Borland R, et al. Supporting smoking cessation: a guide for health professionals. Updated 2012. The Royal Australian College of General Practitioners (RACGP), Melbourne, 2011. Available from: http://www.racgp.org.au/your-practice/guidelines/
  2. Burke H, Leonardi-Bee J, Hashim A, et al. Prenatal and passive smoke exposure and incidence of asthma and wheeze: systematic review and meta-analysis. Pediatrics. 2012; 129: 735-744. Available from: http://pediatrics.aappublications.org/content/129/4/735.long
  3. Cohen RT, Raby BA, Van Steen K, et al. In utero smoke exposure and impaired response to inhaled corticosteroids in children with asthma. J Allergy Clin Immunol. 2010; 126: 491-7. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20673983
  4. Lung Foundation Australia. E-cigarettes. Lung Foundation Australian position statement.. Milton, Queensland, 2014. Available from: http://lungfoundation.com.au/wp-content/uploads/2014/05/Lung-Foundation-Australia-E-Cigarettes-Position-Statement-18-June-2014.pdf
  5. Cooke, A., Fergeson, J., Bulkhi, A., Casale, T. B.. The Electronic Cigarette: The Good, the Bad, and the Ugly. The journal of allergy and clinical immunology. In practice. 2015; 3: 498-505. Available from: http://www.ncbi.nlm.nih.gov/pubmed/26164573
  6. Vardavas, C. I., Anagnostopoulos, N., Kougias, M., et al. Short-term pulmonary effects of using an electronic cigarette: impact on respiratory flow resistance, impedance, and exhaled nitric oxide. Chest. 2012; 141: 1400-6. Available from: http://www.ncbi.nlm.nih.gov/pubmed/22194587
  7. National Health and Medical Research Council. CEO Statement: Electronic cigarettes (e-cigarettes). NHMRC, Canberra, 2015. Available from: http://www.nhmrc.gov.au/filesnhmrc/publications/attachments/ds13nhmrcceostatementecigarettes.pdf
  8. Zwar N. e-Cigarettes: a safe way to quit?. NPS, 2014. Available from: http://www.nps.org.au/publications/health-professional/health-news-evidence/2014/e-cigarettes
  9. Lim, H. B., Kim, S. H.. Inhallation of e-Cigarette Cartridge Solution Aggravates Allergen-induced Airway Inflammation and Hyper-responsiveness in Mice. Toxicological research. 2014; 30: 13-8. Available from: http://www.ncbi.nlm.nih.gov/pubmed/24795794
  10. Sherwood, C. L., Boitano, S.. Airway epithelial cell exposure to distinct e-cigarette liquid flavorings reveals toxicity thresholds and activation of CFTR by the chocolate flavoring 2,5-dimethypyrazine. Respiratory research. 2016; 17: 57. Available from: http://www.ncbi.nlm.nih.gov/pubmed/27184162
  11. McGrath-Morrow, S. A., Hayashi, M., Aherrera, A., et al. The effects of electronic cigarette emissions on systemic cotinine levels, weight and postnatal lung growth in neonatal mice. PloS one. 2015; 10: e0118344. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25706869
  12. Polosa, R., Morjaria, J. B., Caponnetto, P., et al. Persisting long term benefits of smoking abstinence and reduction in asthmatic smokers who have switched to electronic cigarettes. Discovery medicine. 2016; 21: 99-108. Available from: http://www.ncbi.nlm.nih.gov/pubmed/27011045
  13. Quit Victoria, E-cigarettes policy. **, . Available from: http://www.quit.org.au/resource-centre/policy-advocacy/policy/e-cigarettes1