thyroxine to triiodothyronine Lugol's iodine is used in hyperthyroidism:

Correct Answer: B

Rationale: The correct answer is B: Preoperatively for 10-15 days. Lugol's iodine is used preoperatively in hyperthyroidism to reduce vascularity and size of the thyroid gland, making surgery safer. Administering it for 10-15 days before surgery allows for optimal effects. Choice A is incorrect because Lugol's iodine is not used as long term definitive monotherapy due to its potential side effects and limitations. Choice C is incorrect as Lugol's iodine is not typically used postoperatively for 10-15 days. Choice D is incorrect because Lugol's iodine is not used as an adjuvant to carbimazole for long term therapy; carbimazole is commonly used as a long-term therapy for hyperthyroidism.

Correct Answer: B

Rationale: The correct answer is B: Subcutaneous. Insulin is typically administered subcutaneously because it allows for slow and consistent absorption into the bloodstream. Intradermal administration is not ideal for insulin as it may cause skin irritation. Intramuscular administration can lead to erratic absorption and unpredictable blood sugar levels. Intravenous administration is too rapid and can cause dangerous hypoglycemia. Subcutaneous administration provides a balance of absorption rate and is the most common and effective route for insulin delivery.

Correct Answer: A

Rationale: Step-by-step rationale for why choice A (Prednisolone) is correct: 1. Prednisolone is a corticosteroid that can cause hyperglycemia by increasing insulin resistance. 2. This drug can lead to elevated blood glucose levels and worsen glycemic control in diabetic patients. 3. Prednisolone can counteract the effects of insulin, making it difficult to maintain stable blood sugar levels. 4. Therefore, in a patient with diabetes mellitus on insulin therapy, the addition of prednisolone can impair glycemic control. Summary of why the other choices are incorrect: B: Prazosin is an alpha-blocker used to treat hypertension, it does not directly affect glycemia control. C: Paracetamol is an analgesic with no direct impact on blood glucose levels. D: Phenytoin is an antiepileptic drug that does not interfere with glycemic control in diabetes mellitus patients on insulin therapy.

Correct Answer: B

Rationale: The correct answer is B: Human insulins have a faster kinetics of absorption and elimination compared to pork/beef insulins. This is because human insulins are structurally identical to the insulin produced by the human body, leading to better compatibility and quicker absorption. Pork/beef insulins may have different amino acid sequences, causing slower absorption. Choice A is incorrect as potency is not the distinguishing factor between human and pork/beef insulins. Choice C is incorrect because human insulins typically have shorter biological action half-lives due to faster absorption. Choice D is irrelevant as it does not relate to the comparison between human and pork/beef insulins.

Correct Answer: B

Rationale: The correct answer is B: Increasing insulin secretion from pancreas. Sulfonylurea hypoglycaemics stimulate insulin secretion from pancreatic beta cells by binding to ATP-sensitive potassium channels, leading to depolarization and subsequent calcium influx, triggering insulin release. Choice A is incorrect as sulfonylureas do not affect intestinal absorption of glucose. Choice C is incorrect as sulfonylureas do not reverse down-regulation of insulin receptors. Choice D is incorrect as only choice B is correct.