Beta-blockers may cause breathing problems such as shortness of breath, wheezing, or bronchospasm. (Lopressor belongs to a group of drugs called beta-blockers.)
Beta-blockers work by preventing the hormones epinephrine and norepinephrine from attaching to beta receptors in your body. Beta receptors are proteins on the surface of cells in your heart, blood vessels, and lungs. They enable substances, such as the molecules of a drug, to attach to the protein and relay a chemical message.
If you have asthma or chronic obstructive pulmonary disease (COPD), beta-blockers might make it difficult for you to manage your breathing problems.
However, because Lopressor acts on beta receptors mostly in the heart and blood vessels and not your lungs, it’s called a cardioselective beta-blocker. This means that Lopressor may be used safely in people with asthma or COPD whose blood pressure hasn’t improved after using other blood pressure medications. In this situation, their doctor may recommend taking a very low dose of Lopressor.
Be sure to tell your doctor if you have asthma or COPD before you start using Lopressor. Your doctor can recommend whether it’s safe for you to take Lopressor.