PRECAUTIONS: Before using this drug, tell your doctor your medical history, including: any allergies (especially drug allergies), heart problems (e.g., heart rhythm disturbances, heart failure), liver or kidney disease, very low blood pressure, muscular dystrophy, brain tumors (cancer), gastrointestinal problems (e.g., pathologic or iatrogenic narrowing). Before heart surgery, tell your doctor you use this medicine. Limit alcohol intake. Caution is advised when this drug is used in the elderly. This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. This drug is excreted into breast milk and a decision should be made whether to stop the drug or avoid breast-feeding. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Tell your doctor of all nonprescription or prescription drugs you take, especially of: beta-blockers, timolol ophthalmic, digoxin, disopyramide, high blood pressure medication, intravenous (IV) calcium, quinidine, carbamazepine, rifampin, theophylline, lithium, flecainide, cyclosporine, dantrolene, phenobarbital, non-depolarizing muscle relaxants (e.g., pancuronium, tubocurarine). Avoid any drugs that increase your heart-rate (the decongestants phenylephrine, pseudoephedrine and phenylpropanolamine are examples). These drugs are commonly found in over-the-counter cough-and-cold products. Do not eat grapefruit or drink grapefruit juice unless your doctor instructs you otherwise. Do not start or stop any medicine without doctor or pharmacist approval.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include rapid, slow, or irregular heartbeat; dizziness; fainting; and loss of consciousness.