SIADH is associated with which of the following drug?
**Core Concept**
The Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) is a condition characterized by excessive release of antidiuretic hormone (ADH) from the posterior pituitary gland, leading to water retention and hyponatremia. This condition can be caused by various factors, including pharmaceuticals that stimulate ADH release or mimic its effects.
**Why the Correct Answer is Right**
The correct answer is associated with the stimulation of ADH release or its mimicking effect. **Vasopressin** is a synthetic analogue of ADH, commonly used to treat central diabetes insipidus. However, its excessive release or administration can lead to SIADH due to the increased water reabsorption in the kidneys. This is because vasopressin acts on the V2 receptors in the collecting ducts of the kidneys, promoting water reabsorption.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not typically associated with SIADH. However, some drugs like carbamazepine and chlorpropamide can stimulate ADH release, but they are not the most commonly implicated agents in SIADH.
**Option B:** This option is incorrect because beta-blockers like propranolol can cause hypernatremia, not hyponatremia, due to their mild antidiuretic effects.
**Option C:** This option is incorrect because loop diuretics like furosemide can cause hypokalemia and hypovolemia, which can lead to secondary hyperaldosteronism and decreased ADH levels.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that SIADH can be caused by various factors, including pharmaceuticals, central nervous system disorders, and ectopic hormone production. The diagnosis of SIADH requires careful consideration of the patient's clinical presentation, laboratory results, and potential contributing factors.
**Correct Answer:** C.