The unwanted effect of cholecalciferol is:

Correct Answer: D

Rationale: The correct answer is D: Metastatic calcifications. Cholecalciferol, a form of vitamin D, can lead to excessive calcium levels in the blood, causing calcium deposits in soft tissues like the kidneys, lungs, and blood vessels. This can result in metastatic calcifications. Choice A is incorrect as cholecalciferol deficiency, not excess, leads to defective bone mineralization. Choice B is unrelated to cholecalciferol effects. Choice C is not a common side effect of cholecalciferol supplementation.

Correct Answer: A

Rationale: The correct answer is A: Beta-lactam antibiotics. These antibiotics work by inhibiting the synthesis of bacterial cell walls through binding to penicillin-binding proteins, leading to cell lysis. Tetracyclines (B) inhibit protein synthesis, aminoglycosides (C) disrupt protein synthesis by binding to ribosomes, and macrolides (D) interfere with protein synthesis by binding to the 50S ribosomal subunit. Therefore, only beta-lactam antibiotics directly target bacterial cell wall synthesis, making them the correct choice.

Correct Answer: D

Rationale: Rifampin is known to cause hepatotoxicity, making option D the correct answer. Rifampin is metabolized in the liver, potentially leading to liver damage. The other options, dizziness and headache (A), loss of hair (B), and flu-like syndrome with tubular necrosis (C), are not commonly associated with rifampin use. Hepatotoxicity is a serious adverse effect that warrants close monitoring during rifampin therapy.

Correct Answer: C

Rationale: The correct answer is C: Praziquantel. It is effective against a broad spectrum of parasitic infections including cestodosis, trematodosis, and cysticercosis. Praziquantel works by causing paralysis in the parasites, leading to their detachment from the host's tissues. It is well-tolerated and has minimal side effects. Incorrect choices: A: Piperazine - Effective against roundworm infections, not effective for cestodosis, trematodosis, or cysticercosis. B: Ivermectin - Effective mainly against roundworm and certain mite infections, not the ideal choice for cestodosis and trematodosis. D: Pyrantel - Effective against roundworm and hookworm infections, not the optimal choice for cestodosis, trematodosis, or cysticercosis.

Correct Answer: D

Rationale: The correct answer is D: Triamterene. Triamterene is a potassium-sparing diuretic, which means it helps retain potassium in the body. In familial hypokalemic periodic paralysis, there is already low potassium levels, so giving a potassium-sparing diuretic like triamterene could further decrease potassium levels and worsen the condition. Mannitol (A) is an osmotic diuretic, Hydrochlorothiazide (B) is a thiazide diuretic, and Ethacrynic acid (C) is a loop diuretic, all of which can cause potassium loss and exacerbate hypokalemia in this patient.