The drug needs aldosterone present in order to be effective:

Correct Answer: D

Rationale: Rationale for Correct Answer D: Aldosterone is a hormone that regulates salt and water balance by affecting sodium and potassium levels. Hydrochlorothiazide inhibits sodium reabsorption, while amiloride blocks potassium excretion. Since aldosterone promotes sodium reabsorption and potassium excretion, the presence of aldosterone would counteract the effects of both drugs. Therefore, the correct answer is D, as neither drug requires aldosterone for effectiveness. Choice A (Hydrochlorothiazide) is incorrect because it works independently of aldosterone by inhibiting sodium reabsorption in the kidneys. Choice B (Amiloride) is also incorrect as it directly blocks sodium channels in the kidneys, regardless of aldosterone levels. Choice C is incorrect because both drugs are effective regardless of aldosterone presence.

Correct Answer: B

Rationale: The correct answer is B: Hepatotoxicity, peripheral neuropathy. Isoniazid is a commonly used medication for tuberculosis treatment. Hepatotoxicity is a well-known side effect, which can manifest as hepatitis or liver damage. Peripheral neuropathy is another common side effect, characterized by numbness, tingling, or burning sensations in the extremities. These effects are due to the drug's metabolism in the liver and its interference with nerve function. Choice A is incorrect as cardiotoxicity is not a known side effect of isoniazid. Choice C, loss of hair, is not a commonly reported side effect of isoniazid. Choice D, immunotoxicity, is not a major side effect associated with isoniazid use.

Correct Answer: B

Rationale: Step 1: Identify the conditions - ascaridosis and enterobiosis are caused by roundworms and pinworms, respectively. Step 2: Understand mechanism - Pyrantel works by paralyzing the worms, leading to expulsion from the body. Step 3: Specificity - Pyrantel is effective against both roundworms and pinworms. Step 4: Safety - Pyrantel is considered safe for use in treating these infections. Summary: A: Bithionol - used for tapeworm infections, not effective for roundworms or pinworms. C: Praziquantel - effective against tapeworms and flukes, not roundworms or pinworms. D: Suramin - used for African sleeping sickness, not indicated for ascaridosis or enterobiosis.

Correct Answer: D

Rationale: The correct answer is D: Decreased reabsorption of Ca2+ in the loop of Henle. Furosemide is a loop diuretic that inhibits the Na+/K+/2Cl- co-transporter in the thick ascending limb of the loop of Henle, leading to decreased reabsorption of Na+ and Ca2+. This leads to an increase in the excretion of Ca2+ in the urine, resulting in metabolic alkalosis due to loss of H+ ions in exchange for Na+ and Ca2+. A: Increased reabsorption of uric acid is not directly related to furosemide-induced metabolic alkalosis. B: Increased delivery of Na+ to the distal tubule would lead to increased reabsorption of Na+ and water, which would not result in metabolic alkalosis. C: Mild inhibition of carbonic anhydrase would not directly cause furosemide-induced metabolic alkalosis.

Correct Answer: A

Rationale: The correct answer is A: Inhibition of carbonic acid dehydration in the tubular lumen. Acetazolamide inhibits the enzyme carbonic anhydrase in the proximal convoluted tubule of the kidney, leading to decreased reabsorption of bicarbonate ions and subsequent loss of bicarbonate in the urine. This results in a metabolic acidosis which can help alleviate symptoms of congestive heart failure by reducing the workload on the heart. Choice B is incorrect because acetazolamide actually leads to increased bicarbonate excretion, not reabsorption. Choice C is incorrect because acetazolamide does not directly affect Na+ reabsorption in the distal tubule. Choice D is incorrect because acetazolamide does not stimulate H+ reabsorption in the proximal tubule; rather, it inhibits carbonic acid dehydration.