Current evidence for the treatment of hypothyroidism with levothyroxine/levotriiodothyronine combination therapy versus levothyroxine monotherapy

Abstract

SummaryObjectiveHypothyroidism is relatively common, occurring in approximately 5% of the general US population aged ≥12 years. Levothyroxine (LT4) monotherapy is the standard of care. Approximately, 5%‐10% of patients who normalise thyroid‐stimulating hormone levels with LT4 monotherapy may have persistent symptoms that patients and clinicians may attribute to hypothyroidism. A long‐standing debate in the literature is whether addition of levotriiodothyronine (LT3) to LT4 will ameliorate lingering symptoms. Here, we explore the evidence for and against LT4/LT3 combination therapy as the optimal approach to treat euthyroid patients with persistent complaints.MethodsRecent literature indexed on PubMed was searched in March 2017 using the terms “hypothyroid” or “hypothyroidism” and “triiodothyronine combination” or “T3 combination.” Relevant non‐review articles published in English during the past 10 years were included and supplemented with articles already known to the authors.FindingsCurrent clinical evidence is not sufficiently strong to support LT4/LT3 combination therapy in patients with hypothyroidism. Polymorphisms in deiodinase genes that encode the enzymes that convert T4 to T3 in the periphery may provide potential mechanisms underlying unsatisfactory treatment results with LT4 monotherapy. However, results of studies on the effect of LT4/LT3 therapy on clinical symptoms and thyroid‐responsive genes have thus far not been conclusive.ConclusionsPersistent symptoms in patients who are biochemically euthyroid with LT4 monotherapy may be caused by several other conditions unrelated to thyroid function, and their cause should be aggressively investigated by the clinician.

Prevalence of depression among hypothyroid patients attending the primary healthcare and endocrine clinics of King Fahad Hospital of the University (KFHU)

“…Depression was found in 33.9% of the sample, ranging from moderate 10.7%, moderately severe 19.6%, to severe depression 3.6%. The worldwide prevalence of depression among hypothyroid patients was estimated to be around 12.5% in India during 2016;[8] in the United States, it was 5% during 2018,[4] and it was 2% in the United Kingdom during 2013. [5] Differences in prevalence can be attributed to different sample size, gender, and other socioeconomic characteristics between different studied populations.…”

“…[3] It is estimated to be 5% among the population of the United States over the age of 12 years,[4] while in other counties such as the United Kingdom and India, it was estimated to be about 2% and 10.95%, respectively. [35] In Libya in 2008, it was estimated to be 6.18%,[6] whereas in Saudi Arabia in Makkah 2011, the estimated prevalence of hypothyroidism was 47.34% of the study's population.…”

Perspectives, Commentaries, Consensus Reports, Grand Rounds, Meta-Analyses, Systematic Reviews, Narrative Reviews: Collecting useful information in one place

“…The remainder of this month's issue of the journal contains additional reviews covering a variety of conditions and/or procedures, including the management of hyperkalaemia, the treatment of hypothyroidism, integrated left trial evaluation, the use of endobronchial ultrasound trans‐bronchial needle aspiration, and a discussion on exocrine pancreatic insufficiency . Next month we will resume our usual publication pattern to include single study reports.…”

International Journal of Clinical Practice: What was hot in 2018?

“…Of the 100 articles available from 2018 (including editorials and letters), the median number of full‐text downloads was 143. The article with the highest number of full‐text downloads was a review of the current evidence for the treatment of hypothyroidism with levothyroxine/levotriiodothyronine combination therapy vs levothyroxine monotherapy . As of mid‐November 2018, this article was downloaded as a full text 1882 times (668 times as a PDF document and 1214 times in HTML format).…”

“…As such, for articles appearing in 2018, the citation rates as of mid‐November 2018 were overall low (most were zero). Six publications did receive two citations each, and with one exception, all appeared in the February 2018 issue. The Immediacy Index is the average number of times an article is cited in the year it is published, and the journal Immediacy Index indicates how quickly articles in a journal are cited.…”