Theophylline-Furosemide Inactivation?
1 Crawford W. Long Memorial Hospital of Emory University, Atlanta, GA 30365
2 Baptist Hospital of Miami, Miami, FL 33173
To the Editor.
A recent report by Nakagawa1 suggested a possible increased theophylline clearance when furosemide was concomitantly administered. He postulated a decreased hepatic congestion with furosemide which increased theophylline clearance. Conlon et al2 originally investigated this possible interaction but reported an increase in serum theophylline levels, probably due to the apparent volume of distribution contraction associated with diuresis. Conversely, we have observed premature neonates whose serum theophylline concentrations have decreased when furosemide was administered simultaneously.




