Drug InterACTIONs with tobacco smoke

Ron Pohar will be presenting at Pharmacy U Vancouver

Tobacco is the number one cause of preventable disease in Canada and an estimated 48,000 Canadians die each year as a result of smoking. About 4.3 million Canadians currently smoke, or about 14% of the population over the age of 15. When surveyed, 42% of Canadians who smoke cigarettes daily report that they had attempted to quit over the course of a year. Canadians want to quit smoking, but tobacco addiction is difficult to manage due to the symptoms of nicotine withdrawal, which is the key reason for relapse. The chances of success can be improved with support and well-planned quit attempt.

Pharmacists have an important role in this regard. However, one component of a quit attempt that may often be overlooked is the impact that smoking, and, therefore, smoking cessation can have on other medications.

The Drug InterACTIONs with Tobacco Smoke Tool was developed to assist Canadian pharmacists identify drug interactions with the polyaromatic hydrocarbons in tobacco smoke and to provide some guidance on their management. Polyaromatic hydrocarbons are amongst the many chemicals found in tobacco smoke. These compounds have been shown to induce multiple forms of cytochrome P450 enzymes in the liver. Importantly, this is an effect due to polyaromatic hydrocarbons and not nicotine itself. With smoking cessation, the activity of cytochrome P450 enzymes begins to return to ‘normal’, there is a risk of drug toxicity and adverse effects. Healthcare providers need to be aware of the potential for changes in drug metabolism with changes in smoking. Often the interactions between tobacco smoke and a patient’s medication regimen are not considered as part of the quit plan and depending on the pathway through which the medication is metabolized, changes in efficacy of the medication and potential adverse effects can occur.

The Drug InterACTIONs Tool provides a list of the more commonly implicated medications that interact with the polyaromatic hydrocarbons in tobacco smoke. Importantly, the Drug Interactions with Tobacco Smoke Tool can help pharmacists use their clinical judgement to navigate these situations by providing information on the effect of smoking and smoking cessation on the metabolism of key drugs, the clinical relevance of interactions, and guidance on dose adjustment and monitoring.

Ron Pohar, BScPharm, APA completed a Bachelor of Science in Pharmacy degree at the University of Alberta in 1995 and graduated with distinction. He has 25 years of experience as Clinical Pharmacist in Edmonton’s inner city. He specializes in the areas of addictions, smoking cessation, mental health, and geriatrics and provides onsite clinical pharmacy services, including specialized smoking cessation, addictions, and mental health services, to patients at a number of facilities.

Ron Pohar will be presenting at Pharmacy U Vancouver