An elderly woman took a prescription medicine to help her to sleep; however, she felt restless all night and did not sleep at all. The nurse recognizes that this woman has experienced which type of reaction or effect?

Correct Answer: B

Rationale: An idiosyncratic reaction is an unusual or unexpected response to a medication that is not related to the drug's known pharmacological effects. In this case, the elderly woman experienced restlessness instead of sedation, which is contrary to the expected effect of a sleep aid. Idiosyncratic reactions are unpredictable and can vary widely among individuals. Allergic reactions involve the immune system, mutagenic effects involve genetic changes, and synergistic effects involve interactions between multiple drugs. Since the woman's response was unexpected and not consistent with the drug's intended effect, it is classified as an idiosyncratic reaction.

Correct Answer: C

Rationale: Acute porphyria involves heme synthesis defects, triggered by drugs inducing hepatic enzymes (e.g., CYP450). Quinine, used in malaria, isn't a major porphyria trigger. Atenolol, a beta-blocker, is porphyrin-safe, with minimal enzyme induction. Oral contraceptives, containing estrogens/progestins, induce ALA synthase, exacerbating acute porphyria, making them contraindicated. Heparin and amoxicillin don't significantly affect porphyrin metabolism. The contraceptive link reflects hormonal exacerbation of porphyric attacks, critical for safe prescribing in this rare condition.

Correct Answer: A

Rationale: Atropine, a muscarinic antagonist, causes bronchodilation by relaxing bronchial smooth muscle, a true statement used in asthma or COPD. It produces mydriasis (pupil dilation), not miosis (constriction), making that false, as it blocks parasympathetic tone. It's highly lipid-soluble, crossing the blood-brain barrier, so that's false. It doesn't block acetylcholine (ACh) reuptake (there's no such mechanism) but competitively inhibits muscarinic receptors, so that's incorrect. It reduces, not increases, salivary secretions. Bronchodilation is a primary therapeutic effect, reflecting atropine's anticholinergic action, critical for respiratory applications and distinguishing it from sympathomimetics.

Correct Answer: D

Rationale: Luteinizing hormone (LH), from the pituitary, stimulates Leydig cells in the testes to produce testosterone, the primary male sex hormone, making its regulation LH's chief role in men. Sperm production is driven by follicle-stimulating hormone (FSH), not LH, though both support fertility. Secondary sex characteristics, like body hair, depend on testosterone, which LH indirectly influences by controlling its synthesis, not directly regulating the traits. Growth of male sex organs relies on androgens, again tied to testosterone, not LH's direct action. Testosterone regulation is LH's specific function, as it triggers the steroidogenesis pathway, critical for male physiology, distinguishing it from FSH's gamete focus and underscoring its hormonal primacy in this context.

Correct Answer: C

Rationale: St. John's wort, an herbal antidepressant, passes into breast milk, potentially affecting the baby-e.g., sedation or colic-making it unsafe without medical advice. Allergies lack evidence as a concern. Milk production isn't a known issue. Taste changes are unproven. Excretion risk is the primary concern, supported by pharmacokinetics, prioritizing infant safety.