The drug decreases calcium excretion in urine:

Correct Answer: A

Rationale: The correct answer is A: Hydrochlorothiazide (HydroDiuril). It is a thiazide diuretic that inhibits sodium reabsorption in the distal convoluted tubule, leading to decreased calcium excretion in urine. Amiloride (B) inhibits sodium reabsorption in the collecting duct but does not affect calcium excretion. Furosemide (C) acts on the loop of Henle to inhibit sodium and calcium reabsorption, increasing calcium excretion. Acetazolamide (D) is a carbonic anhydrase inhibitor that increases calcium excretion by causing metabolic acidosis and reducing calcium reabsorption.

Correct Answer: D

Rationale: The correct answer is D: Streptomycin. First-line antimycobacterial drugs are those recommended as initial treatment for Mycobacterium tuberculosis infections. Streptomycin is considered a second-line drug due to its potential for serious side effects and development of resistance. Rifampin, Pyrazinamide, and Isoniazid are all first-line drugs supported by extensive clinical evidence and are preferred for initial therapy. Streptomycin is reserved for cases where first-line drugs are contraindicated or ineffective. Therefore, choosing Streptomycin as the correct answer is logical based on its classification as a second-line antimycobacterial drug.

Correct Answer: B

Rationale: The correct answer is B: Rimantadine. Rimantadine is a derivative of adamantane due to its molecular structure containing an adamantane core. This structural similarity allows rimantadine to exert antiviral activity against influenza A viruses by inhibiting the viral uncoating process. Didanozine (A) is a nucleoside reverse transcriptase inhibitor used in HIV treatment, not related to adamantane. Gancyclovir (C) and Foscarnet (D) are antiviral drugs used for treating herpesvirus infections and cytomegalovirus infections, respectively, but they are not derivatives of adamantane.

Correct Answer: C

Rationale: The correct answer is C: Furosemide. Furosemide is a loop diuretic commonly used to treat conditions such as edema and hypertension. In this case, the patient likely required a strong diuretic to manage fluid overload, which is best achieved with a loop diuretic like furosemide. Hydrochlorothiazide (A) is a thiazide diuretic, which is less potent than loop diuretics like furosemide. Mannitol (B) is an osmotic diuretic used for conditions such as cerebral edema and not typically included in routine therapeutic regimens. Fenoldopam (D) is a selective dopamine receptor agonist used for acute hypertension but is not commonly included in routine diuretic regimens like furosemide.

Correct Answer: A

Rationale: The correct answer is A: Propranolol. Propranolol is a non-selective beta-blocker that can potentially cause vasoconstriction, increased blood pressure, and decreased oxygen supply to the heart, leading to myocardial infarction (MI) in susceptible individuals. Nitroprusside (B) and Nitroglycerin (C) are vasodilators that help improve blood flow and decrease cardiac workload, making them unlikely to cause MI. Nifedipine (D) is a calcium channel blocker that primarily affects blood vessels and the heart, but it is less likely to cause MI compared to propranolol.