The role of inhaled opioids and furosemide for the treatment of dyspnea.

Numerous case reports, uncontrolled studies, and small randomized placebo-controlled trials have investigated the role of aerosolized opioids in the treatment of both dyspnea and pain. Recently, aerosolized furosemide was studied for the treatment of dyspnea. A direct effect on either pulmonary stretch receptors or irritant receptors has been proposed to explain the apparent effectiveness of these drugs. A review of the literature found 37 studies and reports: 23 on aerosolized opioids to treat dyspnea, 7 for analgesia, and 7 on aerosolized furosemide. In general, prospective double-blind randomized placebo-controlled trials have investigated the effects of aerosolized opioids on dyspnea and exercise tolerance in patients with stable chronic cardiopulmonary disease, and found no effect. In contrast, the vast majority of studies found that aerosolized opioids relieved dyspnea better than parenteral opioids and with less systemic adverse effects in patients with terminal lung cancer and cystic fibrosis. However, most of these findings come from uncontrolled studies and case reports. Aerosolized opioids also have been found to provide effective analgesia, again with less systemic adverse effect. Small, generally uncontrolled, studies suggest that aerosolized furosemide may relieve dyspnea both in patients with terminal cancer and those with chronic obstructive pulmonary disease. Routine clinical use of aerosolized opioids to treat dyspnea in terminal illness will require large randomized placebo-controlled trials. However, until these studies are done, the risk/benefit ratio favors use of aerosolized opioids and furosemide in selected patients, based on the principle of compassionate care.