Following drugs stimulate erythrogenesis EXCEPT:

Correct Answer: C

Rationale: The correct answer is C: Methotrexate. Methotrexate is a chemotherapy drug that inhibits cell division, including erythroid precursors, thereby suppressing erythrogenesis. Iron dextran, vitamin B12, and folic acid are essential for erythrogenesis by supporting hemoglobin synthesis and red blood cell production. Iron dextran provides iron for hemoglobin synthesis, vitamin B12 is required for DNA synthesis in erythroid precursors, and folic acid is essential for DNA synthesis and cell division. Therefore, methotrexate is the only drug among the choices that does not stimulate erythrogenesis.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Calcium channel blockers are commonly used for angina pectoris, hypertension, and supraventricular tachyarrhythmias. They work by blocking the entry of calcium into the cells, leading to vasodilation, decreased myocardial contractility, and reduced heart rate. This helps in managing angina by reducing oxygen demand, controlling blood pressure, and treating certain types of arrhythmias. Therefore, the main clinical use of calcium channel blockers encompasses all three conditions mentioned in the choices.

Correct Answer: C

Rationale: The correct answer is C: Beta-1 adrenoreceptors (leads to enhanced cardiac output). Dopamine at medium doses mainly influences the Beta-1 adrenoreceptors in the heart, leading to increased heart rate and contractility, thus enhancing cardiac output. This is because dopamine acts as a positive inotropic and chronotropic agent on the heart. Choices A and B are incorrect because dopamine does not primarily act on Alfa-adrenoreceptors (A) causing peripheral vasoconstriction or dopamine receptors (B) causing vasodilation of renal and mesenteric vessels at medium doses. Choice D is incorrect because dopamine at medium doses primarily influences Beta-1 adrenoreceptors, not all the options listed.

Correct Answer: A

Rationale: The correct answer is A: Iodide 1 part in 100000. In an area where goitre is endemic, iodide is used to treat iodine deficiency, which is a common cause of goitre. Iodide supplementation helps in restoring normal thyroid function by providing the necessary iodine for thyroid hormone synthesis. Propylthiouracil and Methimazole are used to treat hyperthyroidism, not goitre. Therefore, they are incorrect choices. Option D is incorrect because not all the choices can be used interchangeably for treating goitre.

Correct Answer: D

Rationale: The correct answer is D because the statement is false. The triphasic pill does not contain luteinizing hormone (LH). The triphasic pill contains varying levels of estrogen and progestin throughout the cycle to mimic the natural hormonal fluctuations in a woman's menstrual cycle. A: The combination pill does contain both estrogen and progestin, making statement A true. B: Ethinyl estradiol and mestranol are indeed commonly used in oral contraceptives, making statement B true. C: The minipill contains progestin alone, making statement C true. In summary, the incorrect statement is D because the triphasic pill does not contain luteinizing hormone. Statements A, B, and C are all true regarding oral contraceptives.