Managing symptoms in hypothyroid patients on adequate levothyroxine: a narrative review

Abstract

The current standard of care for hypothyroidism is levothyroxin e (LT4) monotherapy to reduce levels of thyrotropin (thyroid-stimulating hormone, T SH) within its reference range and amelioration of any symptoms. A substantial minority continues to report hypothyroid-like symptoms despite optimized TSH, however. These symptoms are not specific to thyroid dysfunction and are frequent among the euthy roid population, creating a therapeutic dilemma for the treating clinician as well as the patient. We present a concise, narrative review of the clinical research and evidence -based guidance on the management of this challenging population. The clinician may en deavor to ensure that the serum TSH is within the target range. However, the symptoma tic patient may turn to alternative non-evidence-based therapies in the hope of obtaini ng relief. Accordingly, it is important for the clinician to check for conditions unrelate d to the thyroid that could account for the ongoing symptoms such as other autoimmune condi tions, anemia or mental health disorders. Systematic and thorough investigation of the potential causes of persistent symptoms while receiving LT4 therapy will resolve the problem for most patients. There may be some patients that may benefit from addit ional treatment with liothyronine (LT3), although it is unclear as yet as to which p atient group may benefit the most from combined LT4 + LT3 therapy. In the future, person alized treatment with LT4 + LT3 may be of benefit for some patients with persistent sy mptoms of hypothyroidism such as those with polymorphisms in the deiodinase enzyme 2 (DI O2). For now, this remains a subject for research.

Keywords

• levothyroxine
• hypothyroidism
• triiodothyronine