Lopressor Precautions and Warnings (Cont.)

• Lopressor can interact with certain other medications (see Lopressor Interactions).
   
• Lopressor may hide certain signs of hyperthyroidism. Do not abruptly stop taking Lopressor, as this can cause serious symptoms of hyperthyroidism to appear suddenly and severely. Make sure to talk with your healthcare provider before stopping Lopressor so that it can be done in a safe manner.
   
• Lopressor may cause extreme low blood pressure and/or a slow heart rate in some people. Symptoms can include dizziness, lightheadedness, and fainting. If you develop any of these symptoms, contact your healthcare provider. Extreme low blood pressure is more likely to occur in people who are taking a diuretic, who are on dialysis, or who have diarrhea or vomiting.

Also, make sure not to drive, operate any heavy machinery, or perform any other tasks that require alertness before you know how Lopressor affects you.

• People who have severe congestive heart failure and are taking Lopressor are at an increased risk of worsening their heart failure. Therefore, if you have severe congestive heart failure and your healthcare provider prescribes Lopressor, it is because he or she believes that its benefits outweigh the potential risks. He or she may choose to monitor your situation more closely.
   
• Using beta blockers, such as Lopressor, for a long period of time can, in some cases, lead to heart failure. If you notice any of the following symptoms while taking Lopressor, contact your healthcare provider: unexplained weight gain; swelling of the ankles, feet, or legs; a cough; and shortness of breath (see Symptoms of Congestive Heart Failure for more signs and symptoms).
   
• People who are on Lopressor should not abruptly stop taking the medicine. In previous clinical studies, this has been shown to increase a person's chances of developing angina (chest pain), a heart attack, or serious irregular heart rhythms (arrhythmias). This risk is even greater in people with existing heart disease.
   
• Beta blockers, including Lopressor, are used with caution (if even at all) in people with certain lung diseases, such as asthma, emphysema, chronic bronchitis, or chronic obstructive pulmonary disease (COPD). This is because beta blockers affect the lungs and can cause a narrowing of the airways. This risk is increased in people with certain lung diseases. If you are taking Lopressor and you develop problems breathing or experience wheezing, call your healthcare provider.
   
• For people with allergies, taking Lopressor may increase the reaction to the specific allergens, and the body may not respond to the usual doses of epinephrine.
   
• If you are going to have surgery, let your healthcare provider or dentist know that you are taking Lopressor.
   
• Lopressor is a pregnancy Category C medicine, meaning that there may be an increased risk to the fetus when the medicine is taken during pregnancy. Prior to taking Lopressor, let your healthcare provider know if you are pregnant or thinking of becoming pregnant. If you become pregnant while taking Lopressor, contact your healthcare provider (see Lopressor and Pregnancy for more information).
   
• It is known that Lopressor passes through breast milk. Therefore, if you are breastfeeding and taking Lopressor, it is generally recommended that you stop nursing. Talk with your healthcare provider about your particular situation.