Which of the following is considered a class IA Sodium Channel blocker?

Correct Answer: D

Rationale: The correct answer is D: Procainamide. Procainamide is a class IA antiarrhythmic drug that blocks sodium channels, prolonging the action potential duration. This helps to stabilize the heart's rhythm. Mexiletine (A) is a class IB antiarrhythmic drug that blocks sodium channels with fast recovery kinetics. Amiodarone (B) is a class III antiarrhythmic drug that prolongs repolarization by blocking potassium channels. Quinidine (C) is a class IA antiarrhythmic drug that also blocks sodium channels, but it is not a class IB sodium channel blocker like Procainamide.

Correct Answer: D

Rationale: The correct answer is D: Distal convoluted tubule. Potassium-sparing diuretics, such as spironolactone, act on the distal convoluted tubule by blocking the aldosterone receptor, which leads to decreased sodium reabsorption and potassium retention. This mechanism helps to promote diuresis while preventing potassium loss. Choices A, B, and C are incorrect because potassium-sparing diuretics do not primarily affect the proximal convoluted tubule, loop of Henle, or collecting duct in the kidney.

Correct Answer: D

Rationale: The correct answer is D: Projectile vomiting. Nitroglycerin is not directly associated with causing projectile vomiting. Nitroglycerin commonly causes headaches due to vasodilation, tachycardia due to decreased preload, and dizziness due to hypotension. Projectile vomiting is not a typical side effect of Nitroglycerin toxicity.

Correct Answer: D

Rationale: The correct answer is D: Muscle wasting. Ibuprofen is primarily associated with gastrointestinal side effects like nausea, renal dysfunction, and anemia due to its effects on the stomach, kidneys, and blood. Muscle wasting is not a known direct effect of Ibuprofen toxicity. Ibuprofen is not typically linked to muscle-related issues, making choice D the correct answer.