Which medication is most commonly associated with acute bronchospasm?

Aerosolized pentamidine isethionate is commonly associated with acute bronchospasm, particularly in patients with reactive airway disease or underlying asthma. This medication is primarily used as a prophylactic treatment for Pneumocystis jirovecii pneumonia in immunocompromised patients. However, when administered via aerosol, it can provoke bronchoconstriction as a side effect.

Inhalation of aerosolized agents has been known to irritate bronchial tissues, especially in individuals who have heightened sensitivity in their airways. This can lead to increased airway resistance and difficulty breathing characterized by acute bronchospasm. In contrast, medications like albuterol are bronchodilators used to relieve bronchospasm. Fluticasone is an inhaled corticosteroid that serves to reduce inflammation rather than directly causing bronchospasm, and theophylline is a bronchodilator with a longer duration of action. Therefore, aerosolized pentamidine isethionate stands out due to its potential for provoking immediate bronchoconstriction, particularly in susceptible populations.