Chymotrypsin is an agent containing free sulfhydryl groups. It’s:

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: 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).

Correct Answer: C

Rationale: The correct answer is C: Dobutamine. Dobutamine is a positive inotropic drug that enhances cardiac contractility without affecting the heart rate. It is a non-glycoside structure, making it distinct from options A (Digitoxin) and B (Digoxin), which are glycoside-based cardiac glycosides. Strophanthin (option D) is also a cardiac glycoside. Dobutamine works by increasing the intracellular calcium concentration, leading to improved myocardial performance. It is commonly used in the treatment of heart failure and cardiogenic shock. Thus, the correct choice is C due to its non-glycoside structure and positive inotropic effects.

Correct Answer: B

Rationale: The correct answer is B: Angina pectoris. Thyroid hormones can increase cardiac output and oxygen demand, potentially leading to angina. A: Increases in basal metabolic rate is a common therapeutic effect of thyroid hormones. C: Tremors may occur as a sign of hyperthyroidism but not a direct side effect of thyroid hormone therapy. D: Exopthalmos is a clinical sign of Graves' disease, not a direct side effect of thyroid hormone therapy.