Action of vitamin D3 is:

Correct Answer: D

Rationale: The correct answer is D) All of the above. Vitamin D3 plays a crucial role in maintaining calcium and phosphate balance in the body. A) Increased calcium and phosphate absorption by 1,25-dihydroxyvitamin D3 is correct because this active form of vitamin D enhances the absorption of calcium and phosphate in the intestines, promoting bone health. B) Calcium and phosphate excretion may be decreased by 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 is incorrect because vitamin D actually helps to maintain calcium and phosphate levels in the body by promoting absorption rather than excretion. C) Increased calcium and phosphate resorption by 1,25-dihydroxyvitamin D3; bone formation may be increased by 25,24-dihydroxyvitamin D3 is partially correct but not complete. Vitamin D3 is involved in both promoting calcium and phosphate resorption in the kidneys and bones, as well as bone formation. Educational Context: Understanding the action of vitamin D3 is essential in pharmacology as it is commonly prescribed to manage various conditions related to bone health, mineral balance, and overall well-being across the lifespan. Mastery of this concept is crucial for healthcare professionals to provide effective patient care and medication management.

Correct Answer: C

Rationale: In pharmacology, understanding drug interactions is crucial to ensure safe and effective patient care. In this case, the correct answer is C) Loop diuretics: increase renal excretion. Loop diuretics, such as furosemide, work in the loop of Henle in the kidney to increase the excretion of water and electrolytes, including phosphorus. Therefore, when taken concurrently with phosphorus, loop diuretics can lead to increased renal excretion of phosphorus. Option A) Amiloride: decrease renal excretion is incorrect because amiloride is a potassium-sparing diuretic and does not directly affect phosphorus excretion. Option B) Glucocorticoids: decrease absorption is incorrect because glucocorticoids primarily affect calcium and not phosphorus absorption. Option D) Calcitonin: increases renal excretion is incorrect because calcitonin is a hormone that primarily regulates calcium and bone metabolism, not phosphorus excretion. Understanding these drug interactions is essential for healthcare professionals to prevent adverse effects and ensure optimal therapeutic outcomes for patients. By knowing how different medications interact with phosphorus, nurses and pharmacists can make informed decisions when managing patients with conditions requiring phosphorus supplementation or when prescribing medications that may impact phosphorus levels.

Correct Answer: C

Rationale: In understanding the major causes of hypercalcemia in adults, it is crucial to recognize that renal failure and malabsorption, option C, are not typically primary causes of elevated calcium levels. Hypercalcemia is most commonly associated with conditions such as hyperparathyroidism (option A), where overproduction of parathyroid hormone leads to increased calcium release from bones and decreased excretion from the kidneys. Cancer, with or without bone metastases (option B), can also lead to hypercalcemia due to the production of factors that promote bone resorption. Hypervitaminosis D (option D) can cause increased absorption of calcium from the intestines and can lead to elevated levels. Educationally, this question highlights the importance of recognizing common causes of hypercalcemia in clinical practice. Understanding these key etiologies can aid healthcare providers in prompt diagnosis and management of patients presenting with hypercalcemia, thereby improving patient outcomes. It is essential for healthcare professionals to differentiate between various causes of hypercalcemia to provide optimal care and treatment to patients across the lifespan.

Correct Answer: D

Rationale: In this question, the correct answer is D) All of the above. Gallium nitrate is used for the management of hypercalcemia of malignancy, making option A correct. Option B is also correct because gallium nitrate works by inhibiting bone resorption. Option C is correct as well because one of the potential adverse effects of gallium nitrate is nephrotoxicity, so ensuring adequate hydration and renal output is crucial. Option A is incorrect because gallium nitrate is not FDA-approved for hypercalcemia of malignancy; it is actually used off-label for this purpose. Option B is incorrect as it falsely states that gallium nitrate functions by inhibiting bone resorption. Option C is incorrect as it does not accurately reflect the precautionary measures needed for gallium nitrate administration. Educationally, this question tests the student's understanding of gallium nitrate's pharmacological properties, indications, and potential side effects. It reinforces the importance of knowing the specific uses and monitoring requirements for different medications, highlighting the need for accuracy and attention to detail in pharmacological practice.

Correct Answer: A

Rationale: In the context of pharmacology across the lifespan, understanding how different diuretics act on the renal system is crucial. In this question, the correct answer is A) Acetazolamide (Diamox) because it acts at the proximal tubule. Acetazolamide is a carbonic anhydrase inhibitor that works in the proximal tubule of the nephron to inhibit the reabsorption of bicarbonate ions, leading to diuresis. Option B) Furosemide (Lasix) is a loop diuretic that acts on the thick ascending loop of Henle, not the proximal tubule. Option C) Hydrochlorothiazide (HydroDiuril) is a thiazide diuretic that acts on the distal convoluted tubule. Option D) Spironolactone (Aldactone) is a potassium-sparing diuretic that acts on the collecting duct. Understanding where each diuretic acts in the nephron is essential for nurses and healthcare providers to make informed decisions about their use in patients of different ages and conditions. This knowledge helps in prescribing the appropriate diuretic based on the patient's specific needs and medical history, ensuring safe and effective pharmacological interventions.