In very severe digitalis intoxication the best choice is to use:

Correct Answer: B

Rationale: Step-by-step rationale: 1. Digibind (Digoxin immune fab) is the best choice in severe digitalis intoxication as it binds to digoxin, reducing its effects. 2. Lidocaine is used for cardiac arrhythmias but not specific to digoxin toxicity. 3. Oral potassium supplementation can worsen digoxin toxicity by increasing intracellular potassium. 4. Reducing the dose of the drug is not effective in severe intoxication. Summary: - Digibind is specific for digoxin toxicity by binding to the drug. - Lidocaine, oral potassium, and reducing the drug dose are not effective in severe digitalis intoxication.

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.

Correct Answer: B

Rationale: The correct answer is B because immunodeficiency refers to a disorder or deficiency in the normal immune response. This means that the immune system is not functioning properly, leading to increased susceptibility to infections and other health issues. Choice A describes inflammation, not immunodeficiency. Choice C describes autoimmune disease, which is different from immunodeficiency. Choice D is incorrect because not all the statements are related to immunodeficiency. In summary, the correct answer is B because it directly relates to a malfunction in the immune system, while the other choices describe different processes or conditions.