Final answer:
Levothyroxine is the medication used to treat bradycardia associated with hypothyroidism. It replaces the deficient thyroid hormone, restoring the body's normal metabolic rate and resolving symptoms of bradycardia.
Step-by-step explanation:
The appropriate medication to treat bradycardia in a client with hypothyroidism is levothyroxine. This medication serves as a replacement for the deficient thyroid hormone, which is responsible for regulating the body's metabolism. When the thyroid hormone levels are low, the basal metabolic rate (BMR) decreases, potentially leading to symptoms such as bradycardia. Levothyroxine, a synthetic form of the thyroid hormone thyroxine (T4), helps to restore the normal BMR and alleviate bradycardia associated with hypothyroidism. It is essential to monitor and adjust the level of levothyroxine carefully to avoid complications such as tachycardia.