Thiazide therapy in diabetes insipidus

Q: One of the reasons for the effectiveness of thiazide diuretics is via weight loss in arginine vasopressin resistance (AVP-R), also known as nephrogenic diabetes insipidus.

A) True

B) False

Answer: A

Thiazide diuretics are effective pharmacological therapies for AVP-R.

The treatment modality is volume depletion induced by a low-sodium diet and a thiazide diuretic such as hydrochlorothiazide, 25 mg once or twice daily (or its equivalent). This causes weight loss. As little as 1 to 1.5 kg of weight loss reduces urine output by more than 50 percent, from 10 L/day to below 3.5 L/day. This simple synergistic modality was discovered more than six decades ago, and still works well.

The mechanism of action (MoA) of thiazide diuretics is also mediated by a hypovolemia-induced increase in proximal sodium and water reabsorption, thereby diminishing water delivery to ADH-sensitive collecting tubular segments and reducing urine output. 

Another advantage of thiazides is to decrease the likelihood of hypoglycemia in patients who are also treated with chlorpropamide. It can be used in combination.

#nephrology

#endocrinology

References:

1. Earley LE, Orloff J. THE MECHANISM OF ANTIDIURESIS ASSOCIATED WITH THE ADMINISTRATION OF HYDROCHLOROTHIAZIDE TO PATIENTS WITH VASOPRESSIN-RESISTANT DIABETES INSIPIDUS. J Clin Invest 1962; 41:1988.

2. Webster B, Bain J. Antidiuretic effect and complications of chlorpropamide therapy in diabetes insipidus. J Clin Endocrinol Metab 1970; 30:215.