Drug Interactions
See also How to Use section. Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first. This drug should not be used with the following medications because very serious interactions may occur: cisapride, dofetilide, thioridazine. If you are currently using any of these medications, tell your doctor or pharmacist before starting this product. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: alpha blockers (e.g., prazosin), aluminum hydroxide, anticholinergics (e.g., atropine, scopolamine), calcium channel blockers (e.g., diltiazem, verapamil), chlorpromazine, diazepam, diazoxide, drugs affecting liver enzymes that remove propranolol from your body (such as cimetidine, St. John's wort, certain SSRI antidepressants including fluoxetine/paroxetine/fluvoxamine, protease inhibitors including ritonavir, rifamycins including rifabutin, certain anti-seizure medicines including carbamazepine), drugs that can increase dizziness (e.g., narcotic pain relievers such as morphine, barbiturates such as phenobarbital), drugs that can lower potassium levels (e.g., corticosteroids including prednisone), drugs to treat diabetes (e.g., insulin, sulfonylureas such as glipizide/glyburide), other drugs to treat high blood pressure (e.g., clonidine, hydralazine, methyldopa, reserpine), drugs whose removal from the body is affected by the acid level in urine (e.g., amphetamine, methenamine), epinephrine, haloperidol, other heart medications (e.g., amiodarone, digoxin, disopyramide, propafenone, quinidine), lithium, MAO inhibitors (e.g., furazolidone, isocarboxazid, linezolid, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine), mefloquine, rizatriptan, theophylline, drugs for thyroid disease (e.g., methimazole, propylthiouracil, thyroid supplements including levothyroxine), tricyclic antidepressants (e.g., amitriptyline), warfarin. Check the labels on all your medicines (e.g., cough-and-cold products, diet aids, nonsteroidal anti-inflammatory drugs-NSAIDs for pain/fever reduction) because they may contain ingredients that could increase your blood pressure or cause a fast heartbeat (e.g., pseudoephedrine, phenylephrine, ibuprofen, naproxen). Ask your pharmacist about using those products safely. This medication may interfere with certain laboratory tests (including glaucoma screening test, cardiovascular stress testing using arbutamine, parathyroid test, protein-bound iodide test), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug. This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.