Select the drug which inhibits peristalsis:

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: 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.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Mifepristone is a progesterone receptor antagonist that can be used for both contraception and abortion. As a contraceptive, it prevents implantation by altering the endometrium. As an abortifacient, it induces uterine contractions and softens the cervix, leading to expulsion of the embryo. Incorrect choices: B: FALSE - Mifepristone is indeed used for contraception and abortion, so this statement is inaccurate. C: None - This choice does not provide any information or contribute to the discussion, making it irrelevant. D: All of the above - This is incorrect as not all choices are true. Mifepristone being used for contraception and abortion does not mean that all choices are correct.