Which of the following medications is used in the treatment of diabetes insipidus to control fluid balance?

Reasoning:

Choice A reason: Encouraging increased oral intake is inappropriate for SIADH, as it exacerbates water retention caused by excessive ADH. This would worsen dilutional hyponatremia and fluid overload, potentially leading to severe complications like cerebral edema, making fluid restriction the preferred approach to manage this condition.

Choice B reason: Infusing IV fluids rapidly is contraindicated in SIADH, as it increases fluid overload. Excessive ADH already causes water retention, diluting serum sodium. Rapid IV fluid administration could worsen hyponatremia and lead to neurological complications, such as seizures, due to further dilution of electrolytes.

Choice C reason: Administering glucose-containing IV fluids is not appropriate for SIADH, as it adds to the fluid volume, worsening water retention and hyponatremia. Glucose fluids do not address the underlying ADH excess and may exacerbate dilutional effects, increasing the risk of cerebral edema or other complications.

Choice D reason: Restricting fluids is the appropriate intervention for SIADH, as excessive ADH causes water retention, leading to hyponatremia. Limiting fluid intake helps correct the dilutional effect, increasing serum sodium concentration and reducing the risk of complications like cerebral edema, aligning with the goal of restoring fluid balance.

Reasoning:

Choice A reason: Bradycardia, or slow heart rate, is not typically associated with diabetes insipidus. The condition causes dehydration due to excessive water loss, leading to hypovolemia, which typically increases heart rate (tachycardia) to compensate for reduced blood volume, not slowing it, making bradycardia an unlikely sign.

Choice B reason: Oliguria, or low urine output, is not a feature of diabetes insipidus. The condition results from ADH deficiency, causing the kidneys to produce large volumes of dilute urine (polyuria). Oliguria is more common in conditions like acute kidney injury or dehydration from other causes.

Choice C reason: Hypotension is a clinical sign of diabetes insipidus due to significant water loss from polyuria, leading to hypovolemia. Reduced blood volume decreases blood pressure, as the cardiovascular system struggles to maintain adequate perfusion, making hypotension a common finding in severe or untreated cases.

Choice D reason: Hypertension is not typically associated with diabetes insipidus. The condition leads to dehydration and hypovolemia, which lower blood pressure. Hypertension might occur in conditions like SIADH, where water retention increases blood volume, but this is opposite to the pathophysiology of diabetes insipidus.