NBEO Systemic Disease Practice Exam

Beta blockers are contraindicated in patients with chronic obstructive pulmonary disease (COPD) mainly because they can potentially cause bronchoconstriction. Non-selective beta blockers, in particular, can block both beta-1 and beta-2 adrenergic receptors. The beta-2 receptors are located in the bronchial smooth muscle, and when blocked, they can lead to worsening respiratory symptoms in individuals with COPD, who already have compromised lung function.

In contrast, other classes of glaucoma medications such as prostaglandins, alpha-adrenergic agonists, and carbonic anhydrase inhibitors (CAIs) do not have the same level of concern regarding respiratory effects. Prostaglandins primarily work by increasing the uveoscleral outflow of aqueous humor without significant impact on bronchial tone. Alpha adrenergic agonists may have some systemic effects, but they are generally not linked to significant issues in patients with COPD. Similarly, CAIs act by reducing aqueous humor production and do not interact with the respiratory system in a way that would exacerbate COPD symptoms.

Therefore, the concern with beta blockers in COPD patients underscores the need to select medications that minimize the risk of compromising lung function while managing intraocular pressure in glaucoma.