A nurse is assessing a client who is taking levothyroxine. The nurse should recognize that which of the following findings is a manifestation of levothyroxine overdose?

Choice A rationale Levothyroxine is a synthetic thyroid hormone used to treat hypothyroidism. Overdose or excessive dosing leads to manifestations of hyperthyroidism, which is characterized by increased metabolism and gastrointestinal motility, resulting in diarrhea, not constipation, which is a symptom of hypothyroidism. Choice B rationale An overdose of levothyroxine causes a hypermetabolic state, stimulating the central nervous system, leading to anxiety, agitation, and restlessness, rather than drowsiness. Drowsiness and fatigue are classic manifestations of an underdose or untreated hypothyroidism. Choice C rationale Insomnia is a common manifestation of thyrotoxicosis, which occurs with levothyroxine overdose, due to the overstimulation of the central nervous system. The excessive circulating thyroid hormone increases the metabolic rate, leading to nervousness, difficulty falling asleep, and interrupted sleep. Choice D rationale Hyperreflexia, or brisk deep-tendon reflexes, is a characteristic finding in hyperthyroidism due to increased neuromuscular excitability from high thyroid hormone levels. Hypoactive reflexes are associated with hypothyroidism, indicating a decreased metabolic state.