The most common adverse reaction to insulin is:

Correct Answer: A

Rationale: The most common adverse reaction to insulin therapy is hypoglycemia. Insulin works by lowering blood sugar levels, but if too much insulin is administered or not enough food is consumed, it can result in blood sugar levels dropping too low, leading to hypoglycemia. Symptoms of hypoglycemia include shakiness, sweating, confusion, irritability, dizziness, fast heartbeat, and in severe cases, loss of consciousness or seizures. It is important for individuals on insulin therapy to monitor their blood sugar levels regularly and be aware of the signs and symptoms of hypoglycemia to address it promptly.

Correct Answer: B

Rationale: Metformin is preferred over phenformin because it is less liable to cause lactic acidosis. Lactic acidosis is a potentially life-threatening condition characterized by the buildup of lactic acid in the blood. Phenformin, an older biguanide medication similar to metformin, has been associated with a higher risk of causing lactic acidosis compared to metformin. This risk led to the removal of phenformin from the market due to safety concerns. Metformin, on the other hand, has a lower risk of causing lactic acidosis, making it a safer choice for the management of diabetes.

Correct Answer: A

Rationale: Metformin, a commonly used medication for the management of type 2 diabetes, primarily works by decreasing glucose production in the liver and improving insulin sensitivity in muscle cells. In individuals without diabetes (nondiabetics), there is typically no significant effect on blood sugar levels since their bodies are already functioning properly in terms of glucose regulation. Therefore, metformin would cause little to no lowering of blood sugar levels in nondiabetic individuals.

Correct Answer: C

Rationale: Thiazolidinediones, such as pioglitazone and rosiglitazone, are primarily used as an adjunctive therapy in type 2 diabetes mellitus. They work by decreasing insulin resistance in the body, thus helping to improve blood sugar control. Thiazolidinediones are typically prescribed in combination with other oral antidiabetic medications like sulfonylureas or biguanides to achieve better glycemic control. They are not commonly used as the sole drug in type 1 diabetes mellitus, as their mechanism of action is more beneficial for type 2 diabetes. Thiazolidinediones are not usually used as adjunctive therapy with insulin in type 1 diabetes as well.

Correct Answer: C

Rationale: Hydrocortisone is a glucocorticoid hormone that affects the regulation of electrolyte balance in the body. In the kidneys, hydrocortisone acts to increase the excretion of potassium (K+) while also enhancing the reabsorption of calcium (Ca2+). This results in a decrease in potassium levels in the blood (hypokalemia) and an increase in calcium levels (hypercalcemia). Therefore, the correct action of hydrocortisone is to decrease potassium excretion and increase calcium excretion.