This drug decreases blood levels of high density lipoproteins (HDL):

Correct Answer: D

Rationale: The correct answer is D: Probucol (Lorelco). Probucol decreases blood levels of HDL by inhibiting the enzyme that helps in the production of HDL. Lovastatin (A) works by lowering LDL levels, Nicotinic acid (B) increases HDL levels, and Gemfibrozil (C) works mainly on triglycerides and raises HDL levels. Probucol (D) is specifically known for lowering HDL levels.

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: B

Rationale: The correct answer is B: Gentamycin. Aminoglycosides are a class of antibiotics that inhibit bacterial protein synthesis. Gentamycin falls under this class due to its mechanism of action. Erythromycin (A) is a macrolide antibiotic, Vancomycin (C) is a glycopeptide antibiotic, and Polymyxin (D) is a polypeptide antibiotic. These antibiotics do not belong to the aminoglycosides class, making them incorrect choices.

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.