Treating hypothyroidism in primary care

Can a patient with new-onset hypothyroidism be started on levothyroxine 50 µg/day without endocrine referral?— Marie Laguerre, NP, Weston, Fla.

Most hypothyroidism is managed in primary care, and starting this patient on levothyroxine will certainly help him or her feel better. Obtaining a careful history would help determine the need for an endocrine referral. According to the American Association of Clinical Endocrinologists, age younger than 18 years, pregnancy, history of cardiac disease, lack of response to thyroid hormone (as evidenced by lack of improvement or change in thyroid labs), or presence of thyroid nodules or goiter are all indications for referral to an endocrinologist (Endocr Pract. 2002;8:457-469).

The starting dose for treating hypothyroidism can be 50 µg/day, and dose requirements can be as much as 1.6 µg/kg/day. Checking labs (thyroid-stimulating hormone and free thyroxine) six to eight weeks later will help determine if the dose needs to be adjusted. — Kathy Pereira, MSN, FNP-BC, assistant professor, co-coordinator, Family Nurse Practitioner Program, Duke University School of Nursing, Durham, N.C. (160-3)