Nephrol Dial Transplant (2001) 16: 2303-2309
© 2001 European Renal Association-European Dialysis and Transplant Association
Rapid Communication
Medullary nephrocalcinosis associated with long-term furosemide abuse in adults
1 Department of Nephrology, 2 Department of Diagnostic Radiology and 3 Department of Diagnostic Pathology, Samsung Medical Center, Sunkyunkwan University School of Medicine, Seoul, Korea
Abstract
Background. The use of furosemide is well recognized as a predisposing factor of nephrocalcinosis in infants. Although furosemide is widely used for various medical conditions in adults, its association with nephrocalcinosis in adults is not well established.
Methods. We studied 18 consecutive adult patients (male:female ratio 1:17, age range 21–59 years) who habitually took furosemide to control weight or oedema for long periods of time (range 3–25 years). The daily dose of continuous intake of furosemide ranged from 40 to 2800 mg. Nephrocalcinosis was evaluated using renal ultrasonography (US), computed tomography (CT), or kidney biopsies.
Results. Renal US and CT revealed bilateral nephrocalcinosis of the medullary pyramids in 15 (83.3%) out of 18 patients. The duration of furosemide abuse was similar between nephrocalcinosis positive (NC(+)) and nephrocalcinosis negative (NC(-)) groups. The daily dose of furosemide was nearly 10 times higher in the NC(+) group (range 120–2800 mg, mean 538 mg) than the NC(-) group (range 40–80 mg, mean 67 mg). All patients showed variable degrees of renal insufficiency and there was no difference in creatinine clearance between the NC(+) and NC(-) groups (P>0.05). Kidney biopsies performed in three patients showed focal tubulo-interstitial fibrosis and atrophy and calcifications were observed in outer medullary tubulo-interstitium.
Conclusions. Long-term furosemide abuse can cause medullary nephrocalcinosis in adults, and the risk of developing of nephrocalcinosis seems to be correlated with the daily dose of furosemide. We suggest that long-term furosemide abuse should be suspected in adult patients when medullary nephrocalcinosis is incidentally detected by US or CT.
Keywords: adult; computed tomography; furosemide; nephrocalcinosis; ultrasonography
Notes
Correspondence and offprints requests to: Ha-Young Oh, MD, Department of Nephrology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon Dong, Kangnam Ku, Seoul, 135–710, Korea. Email: ygkim{at}smc.samsung.co.kr