What is the primary mechanism by which non-selective beta-blockers, like Propranolol, can worsen respiratory function in asthmatic patients?
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Correct answer: Antagonism of beta-2 receptors leading to bronchoconstriction
Beta-2 receptors in the lungs mediate bronchodilation. When these are blocked by non-selective antagonists, the parasympathetic-mediated bronchoconstriction remains unopposed, which can trigger a life-threatening asthma attack.
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