The drug blocks the sodium/potassium/chloride cotransporter in the thick ascending loop of Henle:

Correct Answer: B

Rationale: The correct answer is B: Furosemide (Lasix). Furosemide is a loop diuretic that specifically targets the sodium/potassium/chloride cotransporter in the thick ascending loop of Henle. By blocking this transporter, furosemide inhibits sodium reabsorption, leading to increased diuresis. Acetazolamide works in the proximal tubule, hydrochlorothiazide acts on the distal convoluted tubule, and amiloride targets the epithelial sodium channels in the collecting duct. Therefore, they are not the correct choices for blocking the sodium/potassium/chloride cotransporter in the thick ascending loop of Henle.

Correct Answer: A

Rationale: The correct answer is A because Metronidazole is indicated for intra-abdominal infections, vaginitis, and enterocolitis due to its effectiveness against anaerobic bacteria. Pneumonia, influenza, and use as a disinfectant are not appropriate indications as Metronidazole does not target the specific pathogens associated with these conditions. It is important to use this antibiotic judiciously to avoid resistance and unnecessary side effects.

Correct Answer: B

Rationale: The correct answer is B: Rimantadine. Rimantadine is used for the prevention and treatment of influenza A virus infections. It works by inhibiting the replication of the virus. Choice A, Acyclovir, is used for herpes virus infections, not influenza. Choice C, Saquinavir, is an antiretroviral drug used for HIV, not influenza. Choice D, Foscarnet, is used to treat certain viral infections like CMV and herpes, but not for influenza A prevention. Rimantadine specifically targets influenza A virus, making it the correct choice for this question.

Correct Answer: B

Rationale: The correct answer is B: Verapamil. Verapamil is a calcium channel blocker used for hypertension and arrhythmias. It can cause constipation as a side effect, which matches the patient's symptoms. Propranolol (A) can cause diarrhea. Diltiazem (C) and nitroglycerin (D) are less likely to cause constipation compared to verapamil.

Correct Answer: B

Rationale: The correct answer is B: Amiodarone. Amiodarone is commonly used intravenously for various cardiac arrhythmias due to its broad-spectrum antiarrhythmic effects. It is effective in treating ventricular and supraventricular arrhythmias. Quinidine (A) is not commonly used intravenously due to potential side effects. Verapamil (C) is a calcium channel blocker mainly used for supraventricular arrhythmias but is not typically given intravenously. Propranolol (D) is a beta-blocker, which is not the first choice for intravenous treatment of arrhythmias compared to Amiodarone.