Correct Answer: B

Rationale: When a drug name ends in the suffix -navir, it indicates that the drug is a protease inhibitor. Protease inhibitors are commonly used in antiviral therapy to treat infections by inhibiting viral replication. Therefore, the correct answer is B: Protease inhibitor.

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: B

Rationale: Cinchonism is associated with Quinidine, not Valproic acid, Isoniazid, or Ethosuximide. Cinchonism is characterized by symptoms such as tinnitus, dizziness, and headaches. Quinidine, being an antiarrhythmic agent, can lead to this condition as a side effect.

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: B

Rationale: Warfarin primarily affects the liver where it inhibits the synthesis of clotting factors.