A 19-year-old student was diagnosed with hypothyroidism and has started thyroid replacement therapy with levothyroxine (Synthroid). After 1 week, she called the clinic to report that she does not feel better. Which response from the nurse is correct?

A. Bile-acid sequestrants, such as colesevelam, primarily lower serum cholesterol levels. While they may have a modest effect on glucose levels, they do not directly improve insulin sensitivityor significantly reduce hepatic glucose production, which are the main mechanisms of pioglitazone.

B. Thiazolidinediones (TZDs), including pioglitazone (Actos)and rosiglitazone, are oral hypoglycemic agentsused for type 2 diabetes mellitus. They work by activating peroxisome proliferator-activated receptor gamma (PPAR-γ) receptorsin adipose, muscle, and liver tissue. This leads to enhanced insulin sensitivity, improved glucose uptake in peripheral tissues, and modest reduction in hepatic glucose production. TZDs are used as adjuncts to diet and exerciseto improve glycemic control. They are usually well tolerated, with common side effects including upper respiratory tract infection, headache, sinusitis, and myalgia. However, nurses should monitor for weight gain, fluid retention, edema, and signs of heart failure, which are rare but serious adverse effects.

C. Alpha-glucosidase inhibitors(e.g., acarbose, miglitol) work by slowing carbohydrate absorptionin the small intestine to reduce postprandial hyperglycemia. They do not improve insulin sensitivityor reduce hepatic glucose production, so they are mechanistically different from TZDs.

D. Non-insulin injectable drugs, such as GLP-1 receptor agonists (e.g., liraglutide, dulaglutide), are injectable agentsthat enhance glucose-dependent insulin secretion, slow gastric emptying, and promote satiety. Pioglitazone is an oral agent, not an injectable.

A. Aspiration is not required when administering insulin because it is given into the subcutaneous tissue, which does not contain large blood vessels that would necessitate checking for blood return. Current practice guidelines recommend not aspirating, as it can cause unnecessary tissue trauma and discomfort without improving safety.

B. Once an insulin vial is opened, it may be safely kept at room temperaturefor a specified period (commonly up to 28 days, depending on the product). Room temperature insulin is less painful to injectcompared to cold insulin taken directly from the refrigerator. However, unopened insulin should be stored in the refrigerator to maintain stability, and insulin should never be exposed to extreme heat or direct sunlight.

C. Regular insulin (short-acting) and NPH insulin (intermediate-acting) are compatible and can be mixed in the same syringe, allowing administration in a single injection. This reduces the number of injections the client must take. When mixing, the nurse should draw up regular insulin first (clear)and then NPH insulin (cloudy) to avoid contaminating the regular insulin vial.

D. Insulin must be administered into the subcutaneous layer, typically in areas such as the abdomen, thigh, or upper arm. Injecting into a large muscle (intramuscular route) would result in faster and unpredictable absorption, significantly increasing the risk of hypoglycemia. Proper technique includes rotating injection sites to prevent lipodystrophy.