Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Inhaled furosemide prevents bronchoconstriction induced by a number of challenges in asthma. One approach to determine the mechanism underlying this protection has been to examine the effects of diuretics with different or overlapping pharmacologic effects. We have compared the effects of furosemide on sodium metabisulfite-induced bronchoconstriction with those of equivalent diuretic doses of ethacrynic acid, a loop diuretic that, unlike furosemide, does not interact directly with the membrane Na/K/Cl cotransporter protein or inhibit carbonic anhydrase. Eight subjects with mild asthma were studied on five occasions, receiving nebulized furosemide (20 and 40 mg), ethacrynic acid (25 and 50 mg), or placebo (normal saline) in random order and double- blind 10 min before a cumulative dose challenge with inhaled sodium metabisulfite. After placebo the geometric mean sodium metabisulfite PD20 was 7.9 μmol. Furosemide 20 mg and 40 mg increased the PD20 by a mean 1.1 (95% confidence interval, - 0.2-2.4; p > 0.05) and 1.6 (0.4-2.9; p < 0.02) doubling doses to 17.1 and 24.7 μmol, respectively. After inhaled ethacrynic acid 25 mg and 50 mg, the geometric mean PD20 was increased by 0.9 (- 0.4- 2.2; p > 0.05) and 1.5 (0.2-2.8; p < 0.05) doubling doses to 14.5 and 22.4 μmol, respectively. Thus, equivalent diuretic doses of furosemide and ethacrynic acid have a similar inhibitory effect on sodium metabisulfite- induced bronchoconstriction in asthma. This suggests that interaction with the Na/K/Cl cotransporter protein, or carbonic anhydrase inhibition, is not relevant to the effects of furosemide in asthma.

Original publication

DOI

10.1164/ajrccm.151.2.7842188

Type

Journal article

Journal

American Journal of Respiratory and Critical Care Medicine

Publication Date

01/01/1995

Volume

151

Pages

337 - 339