The nurse will assess the patient for which potential contraindication to antitubercular therapy?

Correct Answer: D

Rationale: The correct answer is D, Hepatic impairment. Antitubercular drugs are primarily metabolized by the liver, so hepatic impairment can affect drug metabolism, leading to toxicity or reduced efficacy. Glaucoma (A), anemia (B), and heart failure (C) are not direct contraindications to antitubercular therapy. Glaucoma does not affect drug metabolism, anemia does not interfere with drug efficacy, and heart failure does not directly impact antitubercular drugs' effectiveness.

Correct Answer: A

Rationale: The correct answer is A because the therapeutic index (TI) is a ratio that measures the safety of a drug by comparing the dose that produces therapeutic effects to the dose that causes toxicity. This ratio helps determine the margin of safety of a drug for a specific indication. Choice B is incorrect because TI does not directly measure effectiveness. Choice C is incorrect as bioavailability is a different concept related to drug absorption. Choice D is incorrect because TI focuses on safety and not drug elimination. Therefore, A is the correct answer as it accurately reflects the purpose of the therapeutic index.

Correct Answer: A

Rationale: The correct answer is A: Heart. M2 cholinoreceptors are primarily located in the heart. These receptors are involved in regulating heart rate and contractility by inhibiting adenylate cyclase activity. This leads to decreased cAMP levels, resulting in a decrease in heart rate and contractility. The other choices (B: Glands, C: Smooth muscle, D: Endothelium) are incorrect as M2 receptors are not typically found in these locations. In glands, M3 receptors are more common, in smooth muscle M3 receptors predominate, and in the endothelium, muscarinic receptors are not the primary receptors involved in regulation.

Correct Answer: C

Rationale: The correct answer is C: Atropine. Atropine is useful in the treatment of uterine spasms because it acts as an antispasmodic agent by blocking the action of acetylcholine on smooth muscle, including the uterus. Carbachol (A) is a cholinergic agonist that would exacerbate spasms. Vecuronium (B) is a neuromuscular blocking agent used for muscle relaxation during surgery. Edrophonium (D) is a cholinesterase inhibitor used for diagnosing myasthenia gravis. In summary, Atropine is the correct choice due to its antispasmodic properties, while the other options would not be effective or appropriate for treating uterine spasms.

Correct Answer: A

Rationale: The correct answer is A: Heart. Alpha adrenoreceptor subtypes are mainly associated with smooth muscle tissues, not cardiac muscle like the heart. Alpha-1 receptors are present in blood vessels, prostate, and pupillary dilator muscle, helping in vasoconstriction, ejaculation, and pupil dilation respectively. Alpha-2 receptors are also found in these tissues, modulating neurotransmitter release and smooth muscle contraction. The heart primarily contains beta adrenoreceptor subtypes, which regulate heart rate and contractility. Therefore, the distribution of alpha adrenoreceptor subtypes is not associated with the heart.