American Thyroid Association Quick-Reference GUIDELINES Apps
Issue link: https://eguideline.guidelinecentral.com/i/521958
6 Treatment Î The ATA recommends against the treatment of urticaria with levothyroxine in euthyroid individuals due to a lack of treatment efficacy for this condition. (S-M) Î Factitious thyrotoxicosis should be treated with discontinuation of the exogenous thyroid hormone with education and/or psychiatric consultation as appropriate. (S-L). THERAPIES OTHER THAN LEVOTHYROXINE ALONE Î The ATA recommends that levothyroxine be considered as routine care for patients with primary hypothyroidism, in preference to use of thyroid extracts. (S-M) Note: Although there is preliminary evidence from a short-duration study that some patients may prefer treatment using thyroid extracts, high-quality controlled long- term outcome data are lacking to document superiority of this treatment compared to levothyroxine therapy. Furthermore, there are potential safety concerns related to the use of thyroid extracts, such as the presence of supraphysiologic serum triiodothyronine levels and a paucity of long-term safety outcome data. Î There is no consistently strong evidence of superiority of combination therapy over monotherapy with levothyroxine. Therefore, the ATA recommends against the routine use of combination treatment with levothyroxine and liothyronine as a form of thyroid replacement therapy in patients with primary hypothyroidism, based on conflicting results of benefits from randomized controlled trials comparing this therapy to levothyroxine therapy alone and a paucity of long-term outcome data (See Table 3). (W-M). Î For patients with primary hypothyroidism who feel unwell on levothyroxine therapy alone (in the absence of an allergy to levothyroxine constituents or an abnormal serum TSH), there is currently insufficient evidence to support the routine use of a trial of a combination of levothyroxine and liothyronine therapy outside a formal clinical trial or N-of-1 trial, due to uncertainty in long-term risk benefit ratio of the treatment and uncertainty as to the optimal definition of a successful trial to guide clinical decision-making. (I) Î Currently, genetic testing is not recommended as a guide to selecting therapy for three reasons: • Although there are data suggesting that specific polymorphisms of the type 2 deiodinase gene might be associated with therapeutic response to combination synthetic levothyroxine and liothyronine therapy, controlled confirmatory studies are needed. • Currently genetic testing for these specific deiodinase polymorphisms is only available in the research setting. • The small effect of the type 2 deiodinase gene variants identified so far that do affect thyroid hormone concentrations suggests that other factors (e.g., yet unidentified genetic variants) may play a far greater role in determining an individual patient's thyroid hormone concentrations. (S-M)