Which of the following medications is known to act on the Renin-Angiotensin- Aldosterone System (RAAS), in order to prevent the conversion of angiotensin I to the angiotensin II?

Correct Answer: A

Rationale: ACE (Angiotensin-Converting Enzyme) inhibitors are known to act on the Renin-Angiotensin-Aldosterone System (RAAS) by blocking the conversion of angiotensin I to the active angiotensin II. Angiotensin II is a potent vasoconstrictor and also stimulates the release of aldosterone, leading to increased blood pressure. By inhibiting ACE, ACE inhibitors help to lower blood pressure and reduce the secretion of aldosterone, thereby decreasing the overall vasoconstriction and volume expansion effects of the RAAS. Examples of ACE inhibitors include medications such as lisinopril, enalapril, and captopril.

Correct Answer: B

Rationale: Enteric-coated aspirin reduces GI irritation, an accurate statement for pain management. High doses are for anticoagulation, not pain. Herbs increase bleeding risk, not inflammation relief. Low doses prevent clotting, not inflammation. B enhances safety, making it correct.

Correct Answer: C

Rationale: Prostate cancer is androgen-dependent, relying on testosterone and other androgens for growth. Estrogen therapy suppresses pituitary secretion of luteinizing hormone, reducing testicular androgen production, effectively starving the cancer. This hormonal manipulation is a standard approach. Choice A inaccurately suggests direct cell death, not estrogen's mechanism. Choice B overstates testosterone elimination; it's reduced, not eradicated. Choice D misattributes nutrient blockade, unrelated to estrogen's action. The nurse's best response (C) clarifies estrogen's role in androgen suppression, addressing the client's confusion with precision and relevance to his treatment.

Correct Answer: D

Rationale: Emesis risk depends on chemotherapeutic emetogenicity. Cisplatin, dacarbazine, doxorubicin, and mustine are highly emetogenic, triggering vomiting via chemoreceptor zones. Vincristine, a vinca alkaloid, is least emetogenic, causing neuropathy instead, making it the exception. This lower risk reduces antiemetic needs, easing patient burden during treatment.

Correct Answer: B

Rationale: Cyanocobalamin, or vitamin B12, is essential for red blood cell production and neurological function, and its deficiency directly leads to pernicious anemia, a condition characterized by large, immature red blood cells due to impaired DNA synthesis. This occurs because B12 is crucial for folate metabolism and erythropoiesis, and without it, anemia develops, often accompanied by neurological symptoms like numbness or tingling. Pellagra, however, results from niacin (vitamin B3) deficiency, manifesting as dermatitis, diarrhea, and dementia-unrelated to B12's role. Rickets stems from vitamin D deficiency, causing bone deformities due to poor calcium absorption, not a B12 issue. Scurvy arises from vitamin C deficiency, leading to collagen breakdown and symptoms like bleeding gums, distinct from B12's hematological effects. Pernicious anemia stands out as the correct outcome because B12 deficiency disrupts bone marrow function, and it often requires pharmacotherapy, such as B12 injections, especially if absorption is impaired (e.g., due to lack of intrinsic factor). This specificity eliminates other conditions, highlighting B12's unique role in blood and nerve health.