Before you start taking Coreg CR, tell your doctor about: All the prescription and over-the-counter medications you take, Your allergies, Your medical history and health problems, Your pregnancy or breastfeeding status, Coreg CR is a beta-adrenergic blocking agent that works to lessen the stress from your heart and blood vessels, leading to lower heart rate and blood pressure. Caution should be used when standing from a sitting position. Avoid driving or other hazardous activities until you know how the medication affects you., Heart failure or fluid retention may worsen with Coreg CR dosage increases. Contact your doctor immediately if you have swelling, trouble breathing, or unexplained rapid weight gain., Coreg CR may mask the symptoms of low blood sugar, including rapid heart rate. Diabetic patients should monitor their blood sugar regularly and treat it as directed by their doctor., Coreg CR can cause or worsen the symptoms of slowed or stopped blood flow through the arteries in patients who have peripheral vascular disease. Use caution., Although rare, Coreg CR can worsen kidney function. The risk may be greater in patients who have low blood pressure, ischemic heart disease, diffuse vascular disease, and/or underlying kidney problems., Caution should be used before undergoing major surgery., Coreg CR may mask the signs of overactive thyroid, or hyperthyroidism. In addition, abruptly stopping Coreg CR may worsen the symptoms of hyperthyroidism or cause a thyroid storm., Patients with pheochromocytoma should use caution when taking Coreg CR., Patients with Prinzmetal's variant angina should use caution when taking Coreg CR., Because Coreg CR is also an alpha-blocker, the risk of Intraoperative Floppy Iris Syndrome can occur during cataract surgery., Coreg CR can cause severe allergic reactions, including trouble breathing; swelling of the lips, throat, and tongue; and rash. Patients should seek emergency care right away if any of these effects occur.
