Conditions associated with hypophosphatemia include:

Correct Answer: D

Rationale: The correct answer is D: All of the above. 1. Primary hyperparathyroidism can lead to increased excretion of phosphate in the urine, causing hypophosphatemia. 2. Vitamin D deficiency can result in impaired absorption of phosphate in the intestines, contributing to hypophosphatemia. 3. Idiopathic hypercalciuria can lead to excessive excretion of both calcium and phosphate in the urine, further exacerbating hypophosphatemia. In summary, all three conditions (A, B, and C) are associated with hypophosphatemia due to different mechanisms involving impaired phosphate balance in the body.

Correct Answer: C

Rationale: The correct answer is C: Glycopeptides. Glycopeptides inhibit bacterial cell wall synthesis, not protein synthesis. Macrolides (A), Aminoglycosides (B), and Tetracyclines (D) all inhibit protein synthesis at different stages, making them effective antibiotics against bacterial infections. Glycopeptides specifically target cell wall synthesis by binding to D-alanyl-D-alanine terminus of the growing peptidoglycan chain, leading to cell lysis. Therefore, Glycopeptides do not directly interfere with protein synthesis, distinguishing them from the other antibiotics listed.

Correct Answer: D

Rationale: The correct answer is D because Streptomycin is known to cause ototoxicity and nephrotoxicity. Ototoxicity refers to the damage it can cause to the inner ear, leading to hearing loss and balance issues. Nephrotoxicity refers to its potential to harm the kidneys. The other choices are incorrect because cardiotoxicity (A) and hepatotoxicity (B) are not typically associated with Streptomycin use. Retrobulbar neuritis with red-green color blindness (C) is a side effect of Ethambutol, not Streptomycin.

Correct Answer: B

Rationale: The correct answer is B: Mebendazole or Albendazole. These drugs are commonly used for the treatment of echinococcosis due to their efficacy against tapeworm infections. Mebendazole and Albendazole work by inhibiting the parasite's ability to absorb glucose, leading to its death. Suramin (choice A) is used for African sleeping sickness, not echinococcosis. Piperazine (choice C) is used for roundworm infections, not echinococcosis. Iodoquinol (choice D) is used for amoebic infections, not echinococcosis.

Correct Answer: B

Rationale: The correct answer is B: Blockade of Na+ channels in the collecting duct. Triamterene is a potassium-sparing diuretic that works by inhibiting the epithelial sodium channels (ENaC) in the collecting duct of the nephron. By blocking these channels, triamterene reduces sodium reabsorption, leading to decreased potassium excretion. This mechanism helps maintain potassium levels in the body, making it an effective treatment for conditions like systolic cardiac failure where potassium loss is a concern. Summary: A: Enhancement of K+ reabsorption in the proximal tubule - This is incorrect as triamterene does not act on the proximal tubule for potassium-sparing effects. C: Enhancement of K+ reabsorption in the loop of Henle - This is incorrect as triamterene does not primarily affect potassium reabsorption in the loop of Henle. D: Blockade of aldosterone receptors in the collecting duct - This is