Paradoxical Bronchospasm With SABA Therapy: An Underrecognized Adverse Effect

Paradoxical bronchoconstriction is an underrecognized adverse event that can occur with administration of β₂-agonist-containing inhaler formulations and its significance was showcased in a recently published case report involving a 25-year-old asthmatic patient.

The patient, an African American male with a history of moderate asthma and allergic rhinitis, presented to the study author’s clinic for evaluation and completion of pulmonary function tests (PFTs). The patient complained that he was experiencing episodes of acute shortness of breath following administration of his albuterol hydrofluoroalkane (HFA) inhaler over the past 4 weeks. Other medications the patient was taking included fluticasone/salmeterol diskus and montelukast.

“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),” the study authors reported. Following administration of 4 puffs of Xopenex, the patient’s FVC decreased from 4.17 L (76% predicted) to 4.07 L (74% predicted) and FEV₁ decreased from 2.19 L (50% predicted) to 1.70 L (39% predicted). Administration of 4 puffs of ProAir also yielded a decrease in FVC (4.99 L [107% predicted] to 4.42 L [95% predicted]) and FEV₁ (2.68 L [68% predicted] to 2.25 L [57% predicted]); nebulized albuterol sulfate 2.5mg administration resulted in no change in FVC and an increase in FEV₁.

PFTs were also completed in order to determine the efficacy of ipratropium bromide. “His FVC was unchanged before and after bronchodilator administration at 4.85 L (104% predicted),” the study authors reported. They added, “However, his FEV₁ increased from 2.47 L (62% predicted) to 2.73 L (69% predicted) after 4 puffs of ipratropium bromide were administered.” Therefore, the patient was initiated on ipratropium HFA as a rescue inhaler and albuterol HFA was discontinued. Additionally, the patient’s dose of fluticasone/salmeterol HFA was increased. No symptoms were reported following his transition of therapy.

“Given that our patient experienced a decrease in pulmonary function with inhaled β₂-agonist formulations and an improvement in pulmonary function with nebulized β₂-agonist, we suspect the inactive ingredients in the
inhalers caused bronchoconstriction,” the study authors concluded. “While we believe our patient’s symptoms were most likely secondary to the excipients in his inhalers, clinicians should be aware of paradoxical bronchospasm as an adverse effect of β₂-agonist therapy and counsel patients in appropriate clinical settings.”

Reference

Magee JS, Pittman LM, Jette-Kelly LA. Paraxdoxical Bronchoconstriction with Short-Acting Beta Agonist. American Journal of Case Reports. 2018. DOI: 10.12659/AJCR.910888.