Correct Answer: D

Rationale: Procainamide is a class IA antiarrhythmic drug that acts as a sodium channel blocker by blocking fast sodium channels. Mexiletine is a class IB antiarrhythmic drug, not class IA. Amiodarone is a class III antiarrhythmic, and Quinidine is a class IA antiarrhythmic but not a sodium channel blocker.

Correct Answer: D

Rationale: Midazolam is a benzodiazepine commonly used for its sedative, anxiolytic, and amnestic effects. While dizziness can be a side effect of Midazolam, it is not a primary or common effect. Therefore, the correct answer is D, as it deviates from the typical effects associated with Midazolam.

Correct Answer: D

Rationale: Headaches, tachycardia, and dizziness are common side effects of nitroglycerin due to its vasodilatory properties. Projectile vomiting is not typically associated with nitroglycerin toxicity, making it the correct answer. Therefore, option D is the correct choice.

Correct Answer: D

Rationale: Clozapine is associated with side effects like agranulocytosis (a serious blood condition), sedation (not hyperactivity), and is used as an antipsychotic to treat schizophrenia. Hyperactivity is not a typical effect of Clozapine, making it the correct answer in this context.

Correct Answer: D

Rationale: Drugs ending in -tidine are histamine (H2) receptor antagonists, which block the action of histamine at the H2 receptors, commonly used to reduce stomach acid production. Therefore, the correct answer is an 'H antagonist.' It is essential to be familiar with drug suffixes as they can provide clues to the drug's class and function.