Why are thiazide diuretics used in diabetes insipidus Usmle?
A thiazide diuretic, such as chlorthalidone or hydrochlorothiazide, can be used to create mild hypovolemia which encourages salt and water uptake in proximal tubule and thus improve nephrogenic diabetes insipidus.
Why are thiazides used in diabetes insipidus?
Thiazides have been used in patients with nephrogenic diabetes insipidus (NDI) to decrease urine volume, but the mechanism by which it produces the paradoxic antidiuretic effect remains unclear.
Which combination of testing results is most consistent with central diabetes insipidus?
Blood tests show abnormal levels of many electrolytes, including a high level of sodium. The water deprivation test is the best test to diagnose central diabetes insipidus.
Why do thiazides decrease GFR?
In fact, the most widely accepted hypothesis suggests that the antidiuretic action of thiazides is secondary to increased renal sodium excretion (1,2,6⇓⇓). The renal sodium loss causes extracellular volume contraction leading to lowered GFR and increased proximal tubular sodium and water reabsorption.
How do thiazides reduce GFR?
What is cranial diabetes insipidus?
Cranial diabetes insipidus occurs when there’s not enough AVP in the body to regulate urine production. Cranial diabetes insipidus is the most common type of diabetes insipidus. It can be caused by damage to the hypothalamus or pituitary gland – for example, after an infection, operation, brain tumour or head injury.
What is diabetes insipidus in physiology?
Overview. Diabetes insipidus (die-uh-BEE-teze in-SIP-uh-dus) is an uncommon disorder that causes an imbalance of fluids in the body. This imbalance leads you to produce large amounts of urine. It also makes you very thirsty even if you have something to drink.
Can a thiazide decrease polyuria in patients with diabetes insipidus?
While these results are specific to Li-induced renal effects, they may at least partially explain how a thiazide can serve to decrease polyuria in patients with diabetes insipidus.
Are thiazide diuretics good for diabetics?
Lets take a closer look. The diuretic effect of thiazide diuretics is useful if you have oedema or nephrogenic diabetes insipidus. In a healthy person, the kidneys constantly filter the blood in the body.
What is the role of thiazide in the treatment of nephrogenic DI?
Experiments by Kim et al. suggest that thiazides may serve to upregulate aquaporin channels and ENaC subunits. In rates with lithium-induced nephrogenic DI, HCTZ reversed lithium-induced downregulation of AQP2.
What is nephrogenic diabetes insipidus (DI)?
INTRODUCTION Nephrogenic diabetes insipidus (nephrogenic DI) results from partial or complete resistance of the kidney to the effects of antidiuretic hormone (ADH).