Paradoxical Bronchoconstriction with Short-Acting Beta Agonist.

UNLABELLED: BACKGROUND Asthma is a common disease in the U.S.

POPULATION: Initial therapy in the stepwise approach for asthma management is short-acting β₂-agonist (SABA) therapy as needed for symptom control. However, a significant adverse event that can occur with administration is bronchospasm. Here, we report a case of paradoxical bronchospasm with administration of SABAs during multiple pulmonary function tests (PFTs). CASE REPORT A 25-year-old, non-smoking, African American male with a history of moderate asthma and allergic rhinitis treated with fluticasone/salmeterol diskus, albuterol hydrofluoroalkane (HFA) inhaler, and montelukast presented to our clinic complaining of recurrent episodes of acute shortness of breath immediately following each administration of albuterol for 4 weeks. PFTs were performed with levalbuterol (Xopenex) and albuterol (ProAir), yielding significant decrease in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). Nebulized albuterol and ipratropium bromide also improved FEV1 and FVC. He was successfully transitioned to an ipratropium rescue inhaler for asthma exacerbations. CONCLUSIONS Paradoxical bronchoconstriction is the unexpected constriction of smooth muscle walls of the bronchi that occurs in the setting of an expected bronchodilatory response. This phenomenon has been observed with β₂-agonist-containing inhaler formulations and is an under-recognized adverse event. Theories suggest that the formulation excipients can trigger airway hyperresponsiveness in patients with allergically inflamed airways. Removal of excipients or use of anticholinergic inhalers improved respiratory function. Clinicians should be aware of paradoxical bronchospasm as an adverse effect with common inhaler formulations containing β₂-agonists and counsel patients accordingly in the appropriate clinical setting.