Warnings/Precautions

Tenormin can aggravate breathing difficulties in patients with asthma, chronic bronchitis, or emphysema. In patients with existing slow heart rates (bradycardias) and heart blocks (defects in the electrical conduction of the heart), tenormin can cause dangerously slow heart rates, and even shock. Tenormin reduces the force of heart muscle contraction and can aggravate symptoms of heart failure. Calcium channel blockers, and digoxin (Lanoxin) can cause lowering of blood pressure and heart rate to dangerous levels when administered together with tenormin. In patients with coronary artery disease, abruptly stopping tenormin can suddenly worsen angina, and occasionally precipitate heart attacks. If it is necessary to discontinue tenormin, its dosage can be reduced gradually over several weeks. Tenormin can mask the early warning symptoms of low blood sugar (hypoglycemia), and should be used with caution in patients receiving treatment for diabetes. It is not habit forming. Do not take this medicine if you have had an allergic reaction to it or are allergic to any ingredient in this product. Do not stop taking this medicine without checking with your doctor. Some conditions may become worse when the medicine is suddenly stopped. Your dose may need to be slowly lowered to avoid side effects. Keep all doctor and laboratory appointments while you are taking this medicine. Before you have any medical or dental treatments, emergency care, or surgery, tell the doctor or dentist that you are using this medicine. This medicine may cause drowsiness or dizziness. Do not drive, operate machinery, or do anything else that could be dangerous until you know how you react to this medicine. Before having any allergy tests or shots, tell your doctor that you are using this medicine. This medicine may increase your risk for a serious reaction to the allergy shot. Before taking any new medicine, either prescription or over-the-counter, check with your doctor or pharmacist. This includes any medicines used to treat colds or congestion. Caution is advised when using this medicine in the elderly because they may be more sensitive to the effects of this medicine. For women: this medicine has been shown to cause harm to the human fetus. If you plan on becoming pregnant, discuss with your doctor the benefits and risks of using this medicine during pregnancy. This medicine is excreted in breast milk. if you are or will be breast-feeding while you are using this medicine, check with your doctor or pharmacist to discuss the risks to your baby. For patients with diabetes mellitus: this medicine may mask signs of low blood sugar such as a rapid heart rate. Check blood glucose levels regularly.