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.

Smoking can affect the way your body removes certain drugs such as insulin, theophylline, warfarin, among others. When you stop smoking, your doses of these drugs may need to be adjusted by your doctor. Tell all your doctors and pharmacists that you are quitting smoking and of all the products you take.