Successful treatment of partial nephrogenic diabetes insipidus with thiazide and desmopressin

Objective: To clarify whether combination treatment with desmopressin (DDAVP) and thiazide was clinically effective in a patient with congenital nephrogenic diabetes insipidus (CNDI), we evaluated the treatment in a 7-year-old boy with CNDI who had demonstrated a partial response to DDAVP. Method: Both volume of urine and the presence of nocturia were determined during treatment. Result: Neither the usual therapy of a low-salt diet and a thiazide nor intranasal therapy with a large dose of DDAVP was effective. However, combination treatment resulted in a decrease in urinary volume and the disappearance of nocturia. Conclusion: DDAVP coupled with thiazide may be useful for CNDI in patients who have shown a partial response to DDAVP.