EFFECT OF INHALED FUROSEMIDE ON LUNG CLEARANCE OF TECHNETIUM-99M-DTPA

The diuretic furosemide has been reported to have a protective effect on allergic asthmatic reactions. This study was performed to investiga te the effect of aerosolized furosemide on the lung clearance of Tc-99 m-diethylene triamine pentaacetic acid (Tc-99m-DTPA). Methods: Pulmona ry clearance rates of Tc-99m-DTPA were measured by a computerized gamm a camera with and without the inhalation of aerosol furosemide in 6 no nsmoking normal volunteers (Group 1), 7 smokers without pulmonary dise ase (Group 2) and 11 patients with asthma (Group 3). Results: None of the six normal volunteers showed significant effects of inhaled furose mide on the Tc-99m-DTPA clearance rats. Three of seven smokers present ed an accelerated Tc-99m-DTPA clearance by inhaled furosemide and the other four showed no significant change of Tc-99m-DTPA clearance by fu rosemide inhalation. However, in 10 of 11 patients with asthma, there was significant suppression of Tc-99m-DTPA clearance by furosemide inh alation. Conclusion: Asthmatics possess a furosemide-sensitive mechani sm. Pulmonary aerosol scintigraphy with Tc-99m-DTPA will be useful in predicting the effect of inhaled furosemide therapy.