Does metoprolol (beta blocker) affect the lungs?

From the Guidelines

Metoprolol can affect the lungs, particularly in patients with respiratory conditions, and may cause bronchospasm in susceptible individuals, as noted in a recent study 1.

Key Points to Consider

• Metoprolol is a beta-blocker medication primarily used to treat high blood pressure and heart conditions.
• It can cause bronchospasm (narrowing of the airways) in susceptible individuals, especially those with asthma, COPD, or other respiratory diseases.
• The typical symptoms include wheezing, shortness of breath, or worsening of existing respiratory conditions.
• While metoprolol is considered more "cardioselective" (meaning it primarily targets beta-1 receptors in the heart rather than beta-2 receptors in the lungs), this selectivity is not absolute, especially at higher doses.
• Patients with lung conditions who need beta-blockers may be prescribed more cardioselective options like bisoprolol or nebivolol, or they may require careful monitoring if metoprolol is necessary.
• A recent meta-analysis demonstrated that the use of beta-blockers (including both beta 1-selective and non-selective agents) in patients with COPD and cardiovascular disease is not only safe but also reduces their all-cause and in-hospital mortality, as reported in 1.

Important Considerations for Treatment

• Patients with significant chronic obstructive pulmonary disease who may have a component of reactive airway disease should be given beta blockers very cautiously; initially, low doses of a beta-1–selective agent should be used, as suggested in 1 and 1.
• If there are concerns about possible intolerance to beta blockers, initial selection should favor a short-acting beta-1–specific drug such as metoprolol or esmolol.
• Mild wheezing or a history of chronic obstructive pulmonary disease mandates a short-acting cardioselective agent at a reduced dose (e.g., 12.5 mg of metoprolol orally) rather than the complete avoidance of a beta blocker.
• Anyone experiencing breathing difficulties while taking metoprolol should contact their healthcare provider immediately.

From the FDA Drug Label

Patients with bronchospastic disease, should, in general, not receive beta-blockers, including metoprolol. Because of its relative beta 1 selectivity, however, metoprolol may be used in patients with bronchospastic disease who do not respond to, or cannot tolerate, other antihypertensive treatment

Because beta 1 selectivity is not absolute use the lowest possible dose of metoprolol and consider administering metoprolol in smaller doses three times daily, instead of larger doses two times daily, to avoid the higher plasma levels associated with the longer dosing interval

Metoprolol can affect the lungs, particularly in patients with bronchospastic disease. Due to its beta 1 selectivity, metoprolol may be used in these patients, but with caution and at the lowest possible dose. Bronchodilators should be readily available or administered concomitantly 2.

From the Research

Effects of Metoprolol on the Lungs

• Metoprolol, a beta-1 selective blocker, has been studied for its effects on lung function in patients with asthma and chronic obstructive pulmonary disease (COPD) 3, 4, 5, 6, 7.
• In patients with asthma, metoprolol was found to cause a reduction in forced expiratory volume in 1 second (FEV1) at higher dose levels, and four out of twelve patients experienced exacerbation of their asthma 4.
• A study in patients with COPD found that metoprolol was associated with a higher risk of severe exacerbation, and individuals in the metoprolol group had a significantly greater decrease in logarithmic FEV1 and FVC from baseline to visit on Day 28 compared to the placebo group 5.
• However, another study found that metoprolol can be used safely in CAD patients with COPD, with no significant decrease in FEV1 in either the metoprolol CR or conventional metoprolol group 6.
• A randomized trial found that metoprolol was associated with a higher risk of exacerbation leading to hospitalization, and there was no significant between-group difference in the median time until the first exacerbation 7.

Safety and Efficacy of Metoprolol in Patients with Lung Disease

• The safety and efficacy of metoprolol in patients with lung disease depend on various factors, including the severity of the disease, the dose of metoprolol, and the presence of other health conditions 3, 4, 5, 6, 7.
• Metoprolol can be used safely in patients with COPD who do not have an established indication for beta-blocker use, but the risk of exacerbation leading to hospitalization is higher in these patients 7.
• The use of metoprolol in patients with asthma requires careful monitoring of lung function and adjustment of the dose to minimize the risk of exacerbation 3, 4.