Effect of inhaled furosemide on lung clearance of technetium-99m-DTPA.

Abstract

The diuretic furosemide has been reported to have a protective effect on allergic asthmatic reactions. This study was performed to investigate the effect of aerosolized furosemide on the lung clearance of 99mTc-diethylene triamine pentaacetic acid (99mTc-DTPA). Pulmonary clearance rates of 99mTc-DTPA were measured by a computerized gamma camera with and without the inhalation of aerosol furosemide in 6 nonsmoking normal volunteers (Group 1), 7 smokers without pulmonary disease (Group 2) and 11 patients with asthma (Group 3). None of the six normal volunteers showed significant effects of inhaled furosemide on the 99mTc-DTPA clearance rates. Three of seven smokers presented an accelerated 99mTc-DTPA clearance by inhaled furosemide and the other four showed no significant change of 99mTc-DTPA clearance by furosemide inhalation. However, in 10 of 11 patients with asthma, there was significant suppression of 99mTc-DTPA clearance by furosemide inhalation. Asthmatics possess a furosemide-sensitive mechanism. Pulmonary aerosol scintigraphy with 99mTc-DTPA will be useful in predicting the effect of inhaled furosemide therapy.