Nebulized medications for the treatment of dyspnea: A literature review

Background: Dyspnea significantly impacts quality of life and is one of the most common symptoms in advanced illness. Systemically-administered opioids and benzodiazepines have been the most studied and utilized pharmacologic treatments for refractory dyspnea. Less attention has been given to the use of these medications and others when nebulized. This article presents a review of the literature on the use of nebulized medications for the treatment of dyspnea related to cancer, chronic obstructive pulmonary disease, cystic fibrosis, interstitial lung disease, or experimentally-induced dyspnea. Methods: A systematic review of peer-reviewed literature was conducted using Medline/PubMed, CINAHL, Cochrane, and Google Scholar. Results: Thirty-nine publications were included in this review, including 17 high-quality clinical research studies, as defined by the GRADE system. The evidence for nebulized morphine remains mixed, whereas a potential benefit was suggested for nebulized furosemide, hydromorphone, and fentanyl. No conclusions could be drawn as to which disease population derived greatest benefit from nebulized medications, or whether jet or ultrasonic nebulizers were more effective for the delivery of these medications. Conclusions: More research is needed to assess the characteristics of specific diseases and the combination of different nebulizers and medications that may yield the greatest benefit, and to assess the safety and efficacy of the chronic use of nebulized opioids and furosemide. Until larger, longer-term studies are completed, the use of nebulized medications to treat dyspnea should be assessed on a case-by-case basis and may be considered if the hoped-for benefits outweigh potential harm.