A patient will be receiving a thrombolytic drug as part of the treatment for acute myocardial infarction. The nurse explains to the patient that this drug is used for which purpose?

Correct Answer: C

Rationale: The correct answer is C: To dissolve the clot in the coronary artery. Thrombolytic drugs are used to break down blood clots in the coronary arteries, restoring blood flow to the heart muscle during an acute myocardial infarction. This helps to prevent further damage to the heart tissue and reduce the risk of complications. Choice A is incorrect because the primary goal of thrombolytic therapy is not to relieve chest pain but to restore blood flow. Choice B is incorrect as thrombolytic drugs do not prevent further clot formation but rather address existing clots. Choice D is incorrect because thrombolytic drugs are not used to control bleeding but to dissolve clots.

Correct Answer: A

Rationale: The correct answer is A because stimulation of liver microsomal enzymes can increase drug metabolism, leading to decreased drug levels in the body and requiring a dose increase to maintain therapeutic effect. This is known as enzyme induction. Choices B, C, and D are incorrect because liver enzyme stimulation does not typically result in a decreased drug dose, prolonged drug action, or intensified unwanted drug reactions. It is crucial to understand how enzyme induction affects drug metabolism to optimize drug therapy.

Correct Answer: A

Rationale: The correct answer is A: Idiosyncrasy. Idiosyncrasy refers to a unique and unpredictable reaction to a drug that is not related to the dose or pharmacodynamic properties. This type of reaction can vary greatly among individuals and is not based on common drug responses. B: Hypersensitivity involves an exaggerated immune response to a drug and is dose-dependent. C: Tolerance is the decreased response to a drug over time with repeated use, not an unrelated reaction. D: Teratogenic action refers to drugs causing harm to a developing fetus, not an unrelated reaction in the patient.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Acetylcholine is the primary neurotransmitter at sympathetic ganglia, parasympathetic ganglia, and parasympathetic postganglionic nerve endings. 2. However, at sympathetic postganglionic nerve endings, norepinephrine is the primary neurotransmitter. 3. Therefore, the correct answer is B because acetylcholine is not the specific neurotransmitter at sympathetic postganglionic nerve endings. Summary: A, C, and D are incorrect because acetylcholine is indeed the specific neurotransmitter at those locations.

Correct Answer: C

Rationale: The correct answer is C: Pirenzepine. Pirenzepine is a selective M1 blocker because it specifically targets the M1 subtype of muscarinic receptors. This selectivity reduces the likelihood of off-target effects associated with non-selective antimuscarinic drugs. Atropine (choice A) and Scopolamine (choice B) are non-selective antimuscarinic drugs, affecting multiple muscarinic receptor subtypes. Homatropine (choice D) is a non-selective antimuscarinic drug primarily used for its mydriatic effect in ophthalmology. Therefore, the correct choice is C as it is the only drug that selectively blocks the M1 receptor subtype.