Correct Answer: C

Rationale: Nephritis is not commonly treated with Hydrochlorothiazide. Hydrochlorothiazide is primarily used for managing hypertension (HTN) and congestive heart failure (CHF) by reducing blood pressure and fluid retention. It is not a standard treatment for nephritis, which involves inflammation of the kidneys. Hypercalciuria, characterized by excessive calcium excretion in the urine, is not typically treated with Hydrochlorothiazide either.

Correct Answer: D

Rationale: Stevens-Johnson syndrome is a severe skin reaction that can be associated with Ethosuximide.

Correct Answer: B

Rationale: Nausea is not commonly associated with loop diuretics. Loop diuretics are known to cause electrolyte imbalances such as potassium deficits, metabolic alkalosis, and hypotension due to excessive fluid loss. Nausea is not a typical side effect of loop diuretics.

Correct Answer: C

Rationale: Calcium disodium ethylenediaminetetraacetic acid (CaEDTA) is the antidote for lead poisoning. CaEDTA works by chelating lead, forming a complex that is then excreted in the urine. It is used in chelation therapy to treat lead poisoning by reducing lead levels in the body.

Correct Answer: D

Rationale: Potassium-sparing diuretics exert their primary effects on the distal convoluted tubule in the kidney. By acting on this specific part of the nephron, these diuretics promote sodium excretion while sparing potassium, thus helping to maintain potassium levels in the body. This mechanism differs from other diuretics that may cause potassium loss as a side effect. Understanding the site of action of potassium-sparing diuretics is crucial in clinical practice for managing conditions like hypertension and edema where diuresis is necessary without the risk of hypokalemia.