Final answer:
Eugena's symptoms and elevated TSH suggest hypothyroidism, and the expected change in medication would be an increased dosage of thyroid hormone replacement therapy.
Step-by-step explanation:
Based on Eugena's symptoms of fatigue, increasing constipation, and weight gain, along with elevated serum TSH levels, it appears she may be experiencing hypothyroidism, which is an underactive thyroid condition. The thyroid gland is responsible for producing hormones that regulate metabolism, and when TSH is elevated, it typically indicates that the thyroid is not producing enough of these hormones, thus leading to a lower metabolic rate. Considering these clinical manifestations and lab results, the nurse should anticipate a change in medication that would likely involve an increase in the dosage of thyroid hormone replacement therapy to address the hypothyroidism.