Tobacco: What It Does to Your Body and How Meds Help You Quit

Smoking changes more than your lungs. It alters how some drugs work, speeds up disease risk, and makes infections like tuberculosis harder to fight. If you smoke and take medications—or want to quit—this page gives clear, practical steps and the straight facts about treatments that actually help.

How tobacco affects your health and medicines

Tobacco smoke contains chemicals that speed up enzymes in your liver (especially CYP1A2). That can lower levels of drugs such as clozapine, olanzapine, theophylline and some antidepressants. When you stop smoking those drug levels can jump—sometimes suddenly—so dose changes or monitoring may be needed.

Smoking also raises the risk of heart disease, stroke, chronic lung disease, and certain cancers. It increases severity and spread of infections like tuberculosis, and slows wound healing. If you have chronic conditions or take meds, quitting helps more than you'd think: blood pressure, circulation, lung inflammation, and drug responses all improve.

Medications and tools that help you quit

There are three proven medicine routes that make quitting easier: nicotine replacement therapy (NRT), bupropion, and varenicline.

NRT comes as patches, gum, lozenges, inhalers, and nasal spray. Patches give steady nicotine all day; gum and lozenges handle cravings fast. Many people use a patch for baseline relief and gum or lozenges for sudden urges. NRT lowers withdrawal and doubles your chances of quitting when used correctly.

Bupropion SR (often sold as Zyban) is an antidepressant that also cuts cravings. Typical start is 150 mg daily for three days, then 150 mg twice daily. It can cause dry mouth, trouble sleeping, or vivid dreams. Don’t use it if you have seizures or certain eating disorders without talking to a doctor.

Varenicline (Chantix) targets nicotine receptors in the brain and reduces both cravings and the pleasure from smoking. Usual dosing starts low and reaches 1 mg twice daily after a week. Common side effects are nausea and vivid dreams; many people tolerate it well and it has one of the highest quit rates.

Combining meds and counseling works best. For example, patch plus gum plus brief counseling boosts success over any single approach.

Quick practical tips: pick a quit date, remove triggers (ashtrays, lighters), tell friends and family, plan for cravings (deep breath, walk, gum), and check in with your pharmacist or doctor about drug interactions. If you take meds processed by CYP1A2, tell your prescriber when you quit so they can check levels.

Want more details? We have full articles on addiction medications and how smoking affects infections like tuberculosis. If quitting feels overwhelming, start small: cut back, use NRT, and reach out for help. Every cigarette not smoked improves your health right away.