All of the following statements concerning nicotinic acid (Niacin) are true, EXCEPT:

Correct Answer: B

Rationale: Correct Answer: B Rationale: 1. Nicotinic acid (Niacin) primarily works by inhibiting lipolysis in adipose tissue, leading to decreased free fatty acids and triglycerides. 2. Triglycerides and LDL cholesterol are reduced by Niacin due to its effect on lipid metabolism. 3. High doses of Niacin can indeed cause hepatic or pancreatic disturbances, leading to the discontinuation of doses higher than 3 gm/day. 4. Cutaneous flushing and itching are common side effects of Niacin, not directly related to the drug's effect on apoproteins synthesis.

Correct Answer: A

Rationale: The correct answer is A: Intravenous. Plicamycin is a cytotoxic antibiotic that is administered intravenously to ensure direct delivery into the bloodstream for optimal absorption and distribution to target tissues. Subcutaneous and intranasal routes are not suitable for plicamycin due to its potency and potential irritation at the injection site. Oral administration is ineffective as plicamycin is poorly absorbed through the gastrointestinal tract and extensive first-pass metabolism would render it ineffective. Therefore, intravenous administration is the most appropriate route for plicamycin to achieve desired therapeutic effects.

Correct Answer: C

Rationale: The correct answer is C: Co-trimoxazole. Co-trimoxazole is a combination of sulfamethoxazole and trimethoprim, which are not antibiotics but rather antimicrobial agents. Streptomycin, Penicillin, and Chloramphenicol are all antibiotics that target and kill bacteria. Antibiotics specifically target bacterial infections, while antimicrobial agents can target a broader range of microbes. Therefore, Co-trimoxazole does not fall under the category of antibiotics, making it the correct answer.

Correct Answer: B

Rationale: Step-by-step rationale for Choice B being correct: 1. Trimethoprim inhibits bacterial dihydrofolate reductase. 2. Sulfonamides inhibit dihydropteroate synthetase. 3. Combination blocks sequential steps in folate synthesis. 4. Synergistic effect enhances antimicrobial activity. Summary: A: Incorrect. Combination does not decrease unwanted effects of sulfonamides. C: Incorrect. Combination does not decrease antimicrobial activity. D: Incorrect. Combination does not increase elimination of sulfonamides.

Correct Answer: C

Rationale: Rationale for Correct Answer (C - Metronidazole or emetine): 1. Metronidazole is the drug of choice for hepatic amebiasis due to its high efficacy against Entamoeba histolytica in the liver. 2. Emetine is an alternative option for hepatic amebiasis treatment, especially in cases of resistance to metronidazole. 3. Both drugs have good tissue penetration and are effective against the protozoa causing hepatic amebiasis. Summary of Incorrect Choices: A: Diloxanide or iodoquinol - These drugs are primarily used for treating non-invasive intestinal amebiasis, not the hepatic form. B: Tetracycline or doxycycline - These antibiotics are not the first-line treatment for hepatic amebiasis. D: Erythromycin or azithromycin - These antibiotics are not effective against Entamoeba histolytica in the liver