A 26-year-old woman comes to the office due to persistent fatigue and inability to lose weight. She has also experienced hair loss and dry skin. The patient was diagnosed with primary hypothyroidism 2 years ago and was started on levothyroxine therapy, which she takes on an empty stomach every morning. She exercises 5 times per week, follows very strict caloric restrictions, and has eliminated gluten-containing foods from her diet. Medical history is unremarkable, and the patient has never been pregnant. In addition to levothyroxine, she also takes a cyclic estrogen-progestin oral contraceptive. The patient is sexually active with one partner and does not use tobacco, alcohol, or illicit drugs.
Blood pressure is 124/80 mm Hg and pulse is 70/min. BMI is 26 kg/m². The thyroid gland is diffusely enlarged, firm, and nontender, and the remainder of the physical examination is normal.
Laboratory results are as follows:
Which of the following is the most appropriate next step in management of this patient's condition?

Question

A 26-year-old woman comes to the office due to persistent fatigue and inability to lose weight. She has also experienced hair loss and dry skin. The patient was diagnosed with primary hypothyroidism 2 years ago and was started on levothyroxine therapy, which she takes on an empty stomach every morning. She exercises 5 times per week, follows very strict caloric restrictions, and has eliminated gluten-containing foods from her diet. Medical history is unremarkable, and the patient has never been pregnant. In addition to levothyroxine, she also takes a cyclic estrogen-progestin oral contraceptive. The patient is sexually active with one partner and does not use tobacco, alcohol, or illicit drugs.
Blood pressure is 124/80 mm Hg and pulse is 70/min. BMI is 26 kg/m². The thyroid gland is diffusely enlarged, firm, and nontender, and the remainder of the physical examination is normal.
Laboratory results are as follows:

Which of the following is the most appropriate next step in management of this patient's condition?

Quizplus · Accepted Answer

This patient has primary hypothyroidism, most likely due to chronic lymphocytic (Hashimoto) thyroiditis (eg, diffuse, nontender goiter). She is on appropriate levothyroxine replacement therapy, and although she has persistent symptoms, her normal TSH indicates that she is in a biochemically euthyroid state (some experts suggest checking free T4 for confirmation in such patients, but this is not routinely needed). However, the symptoms of hypothyroidism are nonspecific and overlap extensively with other common conditions (eg, affective disorders, sleep disorders, anemia). Some patients report a greater sense of well-being when their levothyroxine dose is titrated to maintain TSH in the lower half of the normal range, but the dose should not be increased further in an attempt to improve symptoms (Choice D) as doing so may increase the risk of thyrotoxic complications (eg, hypertension, osteoporosis). This patient is on an appropriate dose of levothyroxine; other causes for her symptoms should be sought. (Choice A) Clinicians sometimes add liothyronine (T3) to levothyroxine (T4) in an attempt to alleviate residual symptoms. However randomized studies have shown no benefit of this approach over levothyroxine monotherapy, and the short half-life of liothyronine can lead to nonphysiologic fluctuations in thyroid hormone levels. (Choice C) Estrogen-containing oral contraceptives stimulate synthesis of thyroxine-binding globulin, necessitating a higher dose of levothyroxine to maintain free hormone levels. However, this patient's normal TSH indicates that this effect has been accounted for. In addition, although weight gain is commonly attributed to oral contraceptives, this has not been confirmed in controlled trials. (Choice E) Selenium supplements can lower thyroid peroxidase antibody levels in Hashimoto thyroiditis and may decrease levothyroxine dose requirements in some patients. However, this patient is biochemically euthyroid, and evidence does not show clinically significant enhancements in thyroid function in such patients. Educational objective: Primary hypothyroidism is treated with levothyroxine, with the dose adjusted to maintain serum TSH in the normal (or low-normal) range. Further dose increases or the addition of liothyronine (T3) are not recommended. Hypothyroid symptoms are nonspecific, and patients with residual symptoms should be evaluated for alternate etiologies. __________ References: Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force on thyroid hormone replacement. (http://www.ncbi.nlm.nih.gov/pubmed/25266247) Risks and safety of combination therapy for hypothyroidism. (http://www.ncbi.nlm.nih.gov/pubmed/27137849)

A 26-Year-Old Woman Comes to the Office Due to Persistent