How Quitting Smoking Can Impact the Medicines You Take

How Quitting Smoking Can Impact the Medicines You Take Addiction Nicotine Use After You Quit Print How Quitting Smoking Can Impact the Medicines You Take By Terry Martin facebook twitter Terry Martin quit smoking after 26 years and is now an advocate for those seeking freedom from nicotine addiction. Learn about our editorial policy Terry Martin Medically reviewed by Medically reviewed by Sanja Jelic, MD on April 28, 2016 Sanja Jelic, MD, is board-certified in sleep medicine, critical care medicine, pulmonary disease, and internal medicine.   Learn about our Medical Review Board Sanja Jelic, MD Updated on December 08, 2019 Tim Robberts / Getty Images More in Addiction Nicotine Use After You Quit How to Quit Smoking Nicotine Withdrawal Smoking-Related Diseases The Inside of Cigarettes Alcohol Use Addictive Behaviors Drug Use Coping and Recovery Prescription drugs are known to interact with other drugs and certain foods, but they can also be affected by smokingâ€"and smoking cessation. How Some Prescription Drugs Are Influenced by Cigarette Smoke Foods that we eat are broken down (metabolized) into nutrients that our bodies can use. This process starts with enzymes,  which act as catalysts for the digestive process. There are many types of enzymes. Some of them help break down proteins, some work on carbohydrates, and others on fats. In a similar way, there are enzymes that metabolize prescription drugs. One of these enzymes, CYP1A2, is affected by some of the chemicals in cigarette smoke. These toxins, called PAHs (polycyclic aromatic hydrocarbons) are known to be some of the most potent carcinogens in tobacco smoke.   When PAHs come in contact with CYP1A2 the enzyme becomes more active. This causes medicines that are broken down by CYP1A2 to be metabolized more quickly than they should be. As a result, smokers often require a higher dose than would normally be given. When smoking stops abruptly, such as going into the hospital where smoking isnt allowed or quitting cold turkey, CYP1A2 activity slows down and the larger dose can suddenly be too much.  The chance of negative side effects of medications abruptly increases  as well. It is important that medications be reviewed and possibly adjusted by the prescribing doctor when a person quits smoking. Prescription Drugs That Are Metabolized by CYP1A2 As you can see from this list, a wide variety of medications are metabolized by CYP1A2. Some of them wont cause an adverse reaction following smoking cessation, but others can cause serious side effects if the dose isnt modified or adjusted once a person stops smoking. Dont hesitate to share your quit smoking journey with your healthcare team so that they can keep an eye on any changes you might be experiencing. Alosetron (Lotronex): Antidiarrheal used to treat irritable bowel syndromeClozapine: Sedative drug used to treat  schizophreniaFlutamide (Eulexin): Hormone-based chemotherapy medicineFluvoxamine (Luvox): Used to treat obsessive or compulsive behaviors  Frovatriptan (Frova): Used to treat migraine headachesHaloperidol (Haldol): Treats  schizophrenia, acute psychosis, and is used for tics and vocal utterances of Tourettes syndromeImipramine (Tofranil): Used to treat depressionMelatonin: Over-the-counter supplement used for sleepMexiletine (Mexitil): Antiarrhythmic used to treat irregular heartbeatMirtazapine (Remeron): Antidepressant used to treat depression.  Olanzapine (Zyprexa): Used for schizophrenia, bipolar disorderPropanolol (Inderal): Used to treat  tremors, angina (chest pain), high blood pressure, heart rhythm disorders, and other heart or circulatory conditions. Also used to treat migraine headachesRamelteon (Rozerem): Sedative used for insomniaRasagiline (Azilect): MAOI and antidepressant that can be used to treat Parkinsons diseaseRopinirole (Requip): Dopamine promoter that can be used to treat Parkinsons disease and restless leg syndromeTacrine (Cognex): Used to treat Alzheimers diseaseTheophylline:  Long-term asthma control medicationTizanidine (Zanaflex): Muscle relaxant used to treat muscle spasmsTriamterene (Dyrenium): Diuretic used for fluid retention and high blood pressureZolmitriptan (Zomig): Triptan used to treat migraine headaches Caffeine Is Also Metabolized by CYP1A2 Most ex-smokers will tell you that coffee had a much stronger effect on them after quitting smoking. The usual cup or two in the morning left them jittery and nervous. Theyd chalk it up to the lack of nicotine, and that does play a role, but it probably had more to do with CYP1A2. Smokers metabolize caffeine at approximately four times the rate of non-smokers. It is no wonder that drinking the usual amount of coffee or other caffeinated drink is suddenly uncomfortable following smoking cessation. If you recently quit, you might try cutting your caffeine consumption by half and see how you feel. You can then reduce or increase based on that. Nicotine and Prescription Medicines Nicotine in tobacco and in nicotine replacement therapy can also influence how the body is able to respond to some medications. Nicotine constricts blood vessels and may inhibit the absorption of insulin shots. Nicotine is a stimulant that raises heart rate and blood pressure.  It may contribute to reduced sensitivity to medications used to treat the same.  It is also associated with reduced  sedation from benzodiazepines (tranquilizers) and less pain relief from some opioids. Schedule an Appointment With Your Doctor If you take any prescription medicines and have stopped smoking (or you plan to), check in with your doctor to review how they may be affected by smoking cessation. The good news is that quitting smoking will improve your health and vitality. You may even find that some medications can be eliminated once your body recovers from nicotine addiction. If youre ready to quit, use these quit smoking resources  as a starting point.  There is no time like the present to start work on making your dreams a reality.