Efficacy of indapamide in central diabetes insipidus

Central diabetes insipidus (CDI) results from deficient vasopressin (antidiuretic hormone) secretion and causes polydipsia and polyuria. Desmopressin, a synthetic analog of vasopressin, is the drug of choice in the treatment of CDI, but in mild cases, there are alternative drugs that can be used, including chlorpropamide, carbamazepine, and thiazides.

In this study, we investigated the efficacy of treatment with indapamide, which is an antihypertensive diuretic oral agent, in 20 consecutive patients with CDI. The diagnosis of CDI was established by water-deprivation and vasopressin tests. Before the study, serum and urinary osmolality, daily urinary volume, and serum electrolyte levels were measured in all 20 patients. Indapamide (2.5 mg/d) was administered for 10 days, and then the investigations were performed again; for purposes of comparison, 250 mg/d of chlorpropamide was also administered to 11 of the 20 patients who had been given indapamide.

Indapamide revealed a 40.56% +/- 9.70% (mean +/- SD) (range, 19.6%-55.0%) reduction in 24-hour urinary volume and an increase in urinary osmolality, as well as a decrease in serum osmolality, and was as effective as chlorpropamide (P<.05) in the treatment of CDI.

Because of its low cost and lack of significant adverse effects, indapamide may be a suitable, easy-to-use alternative oral agent for some patients with CDI.