Which of the following CNS stimulants belongs to nootropics?

Correct Answer: D

Rationale: The correct answer is D: Piracetam. Piracetam is a nootropic, which means it enhances cognitive function, memory, and learning. It is not a CNS stimulant like choices A, B, and C. Camphor is a topical analgesic, Pantocrin is an adrenal extract, and Sydnocarb is a stimulant used in treating narcolepsy. Piracetam stands out as a nootropic due to its specific cognitive-enhancing effects, making it the correct choice in this context.

Correct Answer: B

Rationale: Step 1: Chymotrypsin is a protease enzyme, not an agent containing free sulfhydryl groups. Step 2: Protease enzymes like chymotrypsin contain amino acids in their active site, not sulfhydryl groups. Step 3: Therefore, the statement that chymotrypsin is an agent containing free sulfhydryl groups is FALSE. Summary: Choice B is correct because chymotrypsin does not contain free sulfhydryl groups. Choices A, C, and D are incorrect because they do not accurately reflect the nature of chymotrypsin.

Correct Answer: C

Rationale: The correct answer is C: Loperamide. Loperamide is an antidiarrheal medication that works by slowing down gut motility and inhibiting peristalsis in the intestines. This helps to increase the absorption of water and electrolytes, leading to firmer stools. Castor oil (A) and Sorbitol (D) are laxatives that promote peristalsis and bowel movements. Bisacodyl (B) is a stimulant laxative that increases intestinal motility and promotes bowel movements. Therefore, choices A, B, and D are incorrect as they have the opposite effect of inhibiting peristalsis.

Correct Answer: D

Rationale: The correct answer is D because glycosides intoxication can lead to a variety of manifestations affecting different systems. Visual changes may occur due to the effects on the central nervous system. Ventricular tachyarrhythmias can result from the cardiac toxicity of glycosides. Gastrointestinal disturbances are also common, such as nausea, vomiting, and diarrhea. Therefore, all the above choices are correct manifestations of glycosides intoxication. Options A, B, and C are incorrect individually as they only represent some of the possible manifestations, whereas option D encompasses all the correct manifestations.

Correct Answer: D

Rationale: Nifedipine is a calcium channel blocker used as an antianginal agent to treat angina by dilating blood vessels and reducing the workload of the heart. It specifically blocks L-type calcium channels in vascular smooth muscle. Nitroglycerin is a nitrate that works by dilating blood vessels but does not block calcium channels. Dipyridamole is a platelet aggregation inhibitor. Minoxidil is a direct vasodilator that opens potassium channels, not calcium channels. Therefore, the correct answer is D (Nifedipine).