Abstract
Chlorpropamide was given to 3 patients with idiopathic diabetes insipidus, a patient with nephrogenic diabetes insipidus and 8 normal controls. Chlorpropamide decreases, diuresis, increases, the osmolality of urine and decreases the clearance of “free” water which may become negative, without affecting the osmolal clearance.
A patient with nephrogenic biabetes insipidus showed no depressive effect on urine flow during chlorpropamide administration.
In 8 normal controls administration of chlorpropamide neither cause any decrease of diuresis, nor modify the osmolality of urine or the clearance of “free” water and did not affect glomerulal filtration rate, urine 17-KS and 17-OHCS excretion.
During treatment by chlorpropamide on diabetes insipidus administration of sodium chloride in excess (10 gm per day) did not increase the diuresis, and other hypoglycemic drugs such as tolbutamide or biguanide produced no antidiuretic action. In the same patients chlorpropamide was more active than hydrochlorothiazide.
This treatment could be continued effectively for four years without any decrease of its potency. These results lead to the conclusion that chlorpropamide has antidiuretic action similar that of vasopressin.
