Final answer:
The elderly typically require a lower dose of levothyroxine, with slow initiation to avoid cardiac complications. Thyroid hormone levels must be carefully monitored to regulate metabolism and avoid exacerbating any preexisting heart conditions like angina.
Step-by-step explanation:
When prescribing levothyroxine (thyroid hormone replacement) therapy for the elderly, the correct statement is that the presentation of thyroxine excess in the elderly can include worsening angina symptoms. The dose of thyroxine needed by the elderly is typically lower than that needed by the younger adult because of their decreased metabolic rate. A slow initiation of thyroxine therapy is recommended in the elderly to avoid cardiac complications such as angina or arrhythmias. It's also important to monitor Thyroid Stimulating Hormone (TSH) levels and adjust the dose of hormone replacement to achieve an adequate but not excessive hormone level.
Levels of replacement thyroid hormone must be carefully monitored because thyroid hormones regulate metabolism, heat production, protein synthesis, and have a complex interrelationship with other body functions like neurological function and cardiovascular system. Therefore, adjusting hormone levels is crucial for avoiding both the symptoms of hypothyroidism and the risks of excessive thyroid hormone, which could lead to cardiac issues, especially in the elderly who may have preexisting heart conditions.
Additionally, because thyroid hormones like T3 and T4 control the basal metabolic rate, TSH produced by the anterior pituitary plays a critical role in regulating the release of these hormones from the thyroid gland. A deficiency in TSH as suspected in Terry, mentioned in the query, can lead to weight gain and fatigue due to the reduced stimulus for thyroid hormone secretion, thus slowing metabolism.