The nurse is caring for a 14-year-old adolescent who is prescribed levothyroxine for hypothyroidism. The nurse should instruct the client and caregivers to monitor for which of the following potential adverse effects of this medication?

Choice A reason: Hypoglycemia is not an adverse effect of levothyroxine, which treats hypothyroidism by increasing thyroid hormone levels. It may increase metabolism, potentially raising glucose levels, but does not cause low blood sugar, making this an incorrect concern for monitoring. Choice B reason: Hypertension is not a primary adverse effect of levothyroxine. While excessive doses may increase metabolism and heart rate, leading to secondary cardiovascular effects, palpitations are a more specific and common sign of overmedication, making this less critical to monitor. Choice C reason: Palpitations are a potential adverse effect of levothyroxine, especially with excessive dosing, as it increases thyroid hormone levels, stimulating the heart. This causes tachycardia or irregular heartbeats, requiring monitoring to prevent cardiovascular complications in adolescents with hypothyroidism. Choice D reason: Weight loss may occur with levothyroxine due to increased metabolism, but it is an expected therapeutic effect in hypothyroidism, not an adverse one. Palpitations indicate potential overmedication, making them a more critical adverse effect to monitor than weight changes.