Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Stopping smoking can change the way the liver removes certain drugs from the body (such as acetaminophen, caffeine, insulin, oxazepam, pentazocine, propoxyphene, propranolol, theophylline, tricyclic antidepressants such as amitriptyline/imipramine, "water pills"/diuretics such as furosemide). Tell all your doctors and pharmacists that you are quitting smoking.