A nurse is teaching a client who has a new prescription for levothyroxine (Ta) about thyrotoxicosis. The nurse should instruct the client to monitor and report which of the following findings?

Thyrotoxicosis is a life-threatening condition caused by excessive thyroid hormone levels and represents a toxic adverse effect of levothyroxine overdose or excessive dosing. The hallmark manifestations of thyrotoxicosis include fever (hyperthermia), tachycardia (not bradycardia), hypertension, diaphoresis, agitation, tremors, and potentially cardiac dysrhythmias. Fever is a key finding to monitor and report because it reflects the hypermetabolic state driven by excessive thyroid hormone. Bradycardia is the opposite of what occurs; tachycardia and palpitations are expected in thyrotoxicosis. Drowsiness and weight gain are associated with hypothyroidism, the condition being treated, rather than with toxic excess. Clients taking levothyroxine must understand these warning signs so they can seek prompt medical attention and have their dosage adjusted before the condition escalates to thyroid storm, which carries significant mortality. Teaching the client to take the medication exactly as prescribed, avoid sudden changes in dose, and report symptoms of excess thyroid activity is a critical component of safe medication education.