Last updated: January 2018
Suggested citation: Christensen, D. 6.8 Medication interaction effects. In Scollo, MM and Winstanley, MH [editors]. Tobacco in Australia: Facts and issues. Melbourne: Cancer Council Victoria; 2018. Available from http://www.tobaccoinaustralia.org.au/chapter-6-addiction/6-8-medication-interaction-effects
Smoking and the release of nicotine is thought to interact with the metabolism of other psychotropic agents.1 Smoking appears to induce drug-metabolising enzymes that reduce the effectiveness of antipsychotic medications such as clozapine and olanzapine, other psychotropic drugs including benzodiazepines,2 and specific antidepressants, antipsychotics, pain relief medication, medicines for the prevention and treatment of cardiac arrhythmias, and medications for the regulation of menstrual cycles.3 Also, psychotropic blood concentration levels can be lower in smokers compared to non-smokers, where smoking cessation can result in increases in psychoactive blood concentration levels.2, 4
Consequently, the effects of smoking on the metabolism of a range of psychotropic drugs and other medications can cause changes in drug responses among a variety of psychiatric populations and in the general population, necessitating careful monitoring of smokers prescribed such medications (see Section 7.12 for a detailed overview of smoking and mental health).
1. Boksa P. Smoking, psychiatric illness and the brain. Journal of Psychiatry & Neuroscience, 2017; 42(3):147–9. Available from: https://www.ncbi.nlm.nih.gov/pubmed/28440208
2. Desai HD, Seabolt J, and Jann MW. Smoking in patients receiving psychotropic medications: A pharmacokinetic perspective. CNS Drugs, 2001; 15(6):469–94. Available from: https://www.ncbi.nlm.nih.gov/pubmed/11524025
3. Zevin S and Benowitz NL. Drug interactions with tobacco smoking. An update. Clinical Pharmacokinetics, 1999; 36(6):425–38. Available from: https://www.ncbi.nlm.nih.gov/pubmed/10427467
4. Andrade C. Schizophrenia and smoking. Journal of Clinical Psychiatry, 2012; 73(6):e725–e7. Available from: https://www.ncbi.nlm.nih.gov/pubmed/22795210