Q&A
Ask An Expert :: Dr. Charl Els
MBChB, FCPsych[SA], MMedPsych [cum laude], ABAM, MROCC
The responses provided in this question and answer section are based on the writer's experience in treating patients in an addiction psychiatry practice. The information is for educational purposes only and should not be construed as a standard of practice or as consultation recommendations for the management of a specific patient.
Q. What is the physiology of tobacco addiction?
In the following excerpt from the DVD "Safe and Effective Treatment of Tobacco Addiction: Time for a Paradigm Shift", Dr. Els explains the effects of nicotine on the brain.
Q: I have prescribed nicotine replacement patch for several patients with minimal success. I've always followed the monograph, and I'm wondering if it's safe to increase the dosage above the approved dose?
A: Cautiously exceeding the dose and duration of Nicotine Replacement Therapy (NRT) may be acceptable under certain circumstances (e.g. a heavy smoker with a history of several failed quit attempts). No single NRT preparation is deemed more efficacious than any other, but utilizing doses exceeding 21mg (e.g. 21mg + 7mg, 21 mg + 14 mg, etc.), or combining different forms of NRT with each other (e.g. patch plus gum, patch plus inhaler, etc.), appears to be superior in terms of efficacy for smoking cessation. Increasing the dosage above the approved dose does not appear to be associated with an increased cardiovascular or other risk, but the prescriber should ensure that adequate consent is obtained when using dosages that are deemed off-label.
Fiore MC, Jaén CR, Baker TB, et al. Treating Tobacco Use and Dependence: 2008 Update. Clinical Practice Guideline. Rockville, MD: U.S. Department of Health and Human Services. Public Health Service. May 2008.
Is it safe to advise patients to use the nicotine replacement patch and gum at the same time? Can they receive too much nicotine?
A: NRT preparations can be combined with each other. In Canada, there is a labeled indication for patch plus gum, which does not exist in the US. Like any other consumer product or medication, there is a range within which the medication is deemed safe and efficacious. Exceeding the approved dose range for nicotine (within limits) has been reported to be associated with greater success. It is possible for persons to develop symptoms of nicotine toxicity if the dose is exceeded by too much. For the most part, combining a nicotine patch with gum for breakthrough cravings is associated with minimal risk for nicotine toxicity.
Fiore MC, Jaén CR, Baker TB, et al. Treating Tobacco Use and Dependence: 2008 Update. Clinical Practice Guideline. Rockville, MD: U.S. Department of Health and Human Services. Public Health Service. May 2008.
Q: Is there reason to be concerned if my patients continue to smoke the cigarettes while on cessation treatment?
A: In general, there is no excess cardiovascular risk associated with using pharmaceutical grade nicotine replacement therapy, while smoking. However, when initiating medication for smoking cessation, the goal is to have a planned quit date in the near future (for bupropion, varenicline, or using NRT in the reduce-to-quit fashion), or to have a quit date already executed when initiating NRT.
Fiore MC, Jaén CR, Baker TB, et al. Treating Tobacco Use and Dependence: 2008 Update. Clinical Practice Guideline. Rockville, MD: U.S. Department of Health and Human Services. Public Health Service. May 2008.
Q: I've heard that coffee drinking while quitting tobacco can be a problem. Can you elaborate?
A: A liver enzyme that is induced by tar in tobacco smoke metabolizes caffeine. As such, smokers can metabolize caffeine (and some other psychotropic compounds) faster than a non-smoker. When a smoker discontinues smoking, the liver's enzyme (CYP450 1A2) returns to its normal level after several days to weeks, thus rendering the person less capable of metabolizing caffeine in the same fashion he/she previously could. It is deemed prudent to advise smokers who are preparing to quit smoking to cut back on caffeine consumption, in view of the anticipated pharmacokinetic changes that will likely occur when no longer inhaling tar-containing tobacco smoke.
Importantly, it is not nicotine itself that induces liver enzymes and may interfere with caffeine metabolism. Rather, it is the polycyclic aromatic hydrocarbons found in tobacco smoke that does so. The implication is that when initiating NRT (or bupropion, or varenicline), the liver enzyme changes are likely to occur, and the risk of caffeine intoxication may be real if the smoker does not reduce consumption prior to quitting smoking.
Kroon LA. Drug interactions with smoking. Am J Health Syst Pharm 2007;64:1917-21.
Q: I have a patient who has significantly reduced her daily cigarette use by supplementing with NRT. Whenever we try to wean her from the patch and gum, though, her smoking increases dramatically. How long can a patient safely remain on NRT?
A: Although the monograph suggests a limited period of time for the use of NRT, the principles of good clinical practice suggests that the duration of treatment can be safely exceeded if deemed necessary on an individualized basis. The general philosophy for addiction treatment is: "As long as it takes", provided the modality used is deemed safe and therapeutic benefits are obvious, with the appropriate patient consent obtained.
Q: I am concerned about the recent research linking cardiovascular events with Varenicline. What are your thoughts?
A: Varenicline is not considered to be associated with excess cardiovascular risk. The risk of smoking far outweighs the risk of any of the medications used for smoking cessation, and patients should be counseled in this regard. A recent meta-analysis (Singh, et al., 2011), published in the Canadian Medical Association Journal, analyzed data from 14 trials involving varenicline in more than 8,000 patients, and suggested an increased cardiovascular risk. However, the existing pooled information on varenicline does not support a cardiovascular risk. Physicians should continue to weigh the risks and benefits of medication, compared to the risks of ongoing tobacco consumption in their patients.
Q: I have several pregnant patients in my practice, and a few who smoke. What therapies can I safely try?
A: The use of nicotine gum is considered reasonable as a second-line treatment option for smoking cessation during pregnancy. Bupropion is not contraindicated, and the risks and benefits need to be considered, compared with the risks of ongoing smoking during pregnancy. Varenicline has not been studied during pregnancy and is for that reason not considered an option for treatment.
Valuable resource to consider: http://www.pregnets.org/, www.motherrisk.org
Q: Some of my patients have complained of headaches while quitting smoking. Can you explain this?
A: Headaches are considered one of the most common symptoms experienced by patients. There are more than 200 different kinds of headaches, with likely thousands of causes for headaches, of which nicotine withdrawal is one, and anxiety (related to quitting smoking may be another). The important thing would be to rule out more serious causes of headaches and to treat such on their own merit. Quitting smoking may be associated with headaches for a number of reasons, which tends to be self-limiting and finite in duration.
