Drug Interactions With Oral Inhaled Medications

Objective: To evaluate the potential for drug interactions with oral inhaled medications (OIMs). OIMs include bronchodilators (β-agonists and antimuscarinics), corticosteroids, combination products (2 or more agents combined within a single inhalation device), antibiotics, prostacyclins, anesthetics, acetylcysteine, mucolytics, insulin, antivirals, nitric oxide, and nicotine replacement. Data Sources: A systemic literature search (1980 to May 2018) was performed using PubMed and EBSCO to locate relevant articles. The MESH terms used included each specific medication available as an OIM as well as "drug interactions." DAILYMED was used for product-specific drug interactions. Study Selection and Data Extraction: The search was conducted to identify drug interactions with OIMs. The search was limited to those articles studying human applications with OIMs and publications using the English language. Case reports, clinical trials, review articles, treatment guidelines, and package labeling were selected for inclusion. Data Synthesis: Primary literature and package labeling indicate that OIMs are subject to pharmacokinetic and pharmacodynamics interactions. The most frequently identified clinically significant drug interaction is an inhaled corticosteroid when combined with a potent CYP 450 inhibitor such as a protease inhibitor or antifungal. Conclusions: The available literature indicates that OIMs are associated with clinically significant drug interactions and subsequent adverse reactions. Clinicians in all practice settings should be mindful of this potential to minimize adverse effects and optimize therapy.