The nurse is discussing adverse effects of antitubercular drugs with a patient who has active tuberculosis. Which potential adverse effect of antitubercular drug therapy should the patient report to the prescriber?

Correct Answer: D

Rationale: The correct answer is D: Numbness and tingling of extremities. This is a potential adverse effect of antitubercular drugs known as peripheral neuropathy. Patients should report this to the prescriber immediately as it may indicate a serious side effect that requires prompt intervention to prevent further nerve damage. A: Gastrointestinal upset is a common side effect of antitubercular drugs but is usually not considered serious enough to warrant immediate reporting. B: Headache and nervousness are not typically associated with antitubercular drugs. While they may occur as side effects, they are not the most concerning adverse effects. C: Reddish-orange urine and stool are common side effects of rifampin, an antitubercular drug, and are not typically harmful. This side effect is usually harmless and does not require immediate reporting.

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.

Correct Answer: C

Rationale: The correct answer is C: Beta1 receptor. Stimulation of Beta1 receptors in the heart leads to increased heart rate, contractility, and conduction velocity. This is crucial for the direct effects on the heart. Alpha1 receptors (choice A) primarily cause vasoconstriction, not direct effects on the heart. Alpha2 receptors (choice B) inhibit norepinephrine release and have minimal effects on the heart. Beta2 receptors (choice D) are mainly found in the lungs and blood vessels, leading to bronchodilation and vasodilation, rather than direct effects on the heart.