Physician Information About: SMOKING CESSATION AND CONCOMITANT PRESCRIPTION DRUG USE

Smoking changes how the body reacts to many medications. The efficacy of certain medications are decreased with concomitant smoking, and must be given in higher doses in the smoking patient. Also, when a patient stops smoking, the levels of these medications in the body may change. Thus, particular attention must given to the smoking patient or patient attempting to quit, who is taking the following medications:

When a patient quits smoking, the decreased metabolism of many medications can result in significantly higher medication blood levels. This could increase therapeutic efficacy, but could also cause increase medication side effects (Lavin, Siris, and Mason, 1996). Consequently, close monitoring is needed to determine if medication dosage needs adjustment. It should be noted that most of the effects of smoking on drug metabolism is caused by the hydrocarbon agents in cigarette smoke, not by the nicotine. Clinicians need not avoid the use of nicotine replacement medications.

According to the American Psychiatric Association's Practice Guideline for the Treatment of Patients with Nicotine Dependence (Hughes, et al., 1996), psychiatric medications likely to follow the pattern of increased blood levels after smoking cessation include: Clomipramine, Clozapine, Desipramine, Desmethyldiazepam, Doxepin, Fluphenazine, Haloperidol, Imipramine, Oxazepam, Nortriptyline, and Propranolol. Abstinence may or may not affect the blood levels of Alprazolam, Chlorpromazine, and Diazepam. Abstinence does not appear to increase blood levels of Amitriptyline, Chlordiazepoxide, Ethanol, and Lorazepam.

**The preceding information was derived from the references cited above, and Clear Horizons, a publication of the University of Rochester.

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