We gave piretanide, a new diuretic, at two dose levels to six normal subjects. Sodium excretion increased six to eightfold in the first two hours, and diuresis was completed within four hours. There was a simultaneous increase in the excretion of calcium which exceeded the amount present In the mobilized extracellular fluid. The resulting deficit of calcium produced a small but significant fall in serum calcium corrected for protein. After diuresis ended, calcium was retained but not sodium, when compared to basal values on the previous day. The fall in urinary calcium and the failure to correct the sodium deficit may both have resulted from increased secretion of parathyroid hormone (PTH), which increases calcium reabsorption and decreases sodium reabsorption. The role of PTH in the long-term effects of diuretics on sodium and calcium excretion requires further study.
Casco, Cristina; Day, Patricia Fainstein; and Mautalen, Carlos
"The Acute Effect of Piretanide upon Serum and Urinary Calcium in Normal Subjects,"
Henry Ford Hospital Medical Journal
: Vol. 28
Available at: https://scholarlycommons.henryford.com/hfhmedjournal/vol28/iss2/8