Treatment of hypothyroidism with levothyroxine plus liothyronine: a randomized, double-blind, crossover study
Arch. endocrinol. metab. (Online)
;
60(6): 562-572, Nov.-Dec. 2016. tab, graf
Article
in English
| LILACS
| ID: biblio-827785
ABSTRACT
ABSTRACT Objective To compare the effects of a unique fixed combination levothyroxine/liothyronine (LT4/LT3) therapy in patients with primary hypothyroidism. Subjects and methods This is a randomized, double-blind, crossover study. Adults with primary hypothyroidism (n = 32, age 42.6 ± 13.3, 30 females) on stable doses of LT4 for ≥ 6 months (125 or 150 μg/day) were randomized to continue LT4 treatment (G1) or to start LT4/LT3 therapy (75/15 μg/day; G2). After 8 weeks, participants switched treatments for 8 more weeks. Thyroid function, lipid profile, plasma glucose, body weight, electrocardiogram, vital signs, and quality of life (QoL) were evaluated at weeks 0, 8 and 16. Results Free T4 levels were significantly lower while on LT4/LT3 (G1 1.07 ± 0.29 vs. 1.65 ± 0.46; G2 0.97 ± 0.26 vs. 1.63 ± 0.43 ng/dL; P < 0.001). TSH and T3 levels were not affected by type of therapy. More patients on LT4/LT3 had T3 levels above the upper limit (15% vs. 3%). The combination therapy led to an increase in heart rate, with no significant changes in electrocardiogram or arterial blood pressure. Lipid profile, body weight and QoL remained unchanged. Conclusions The combination therapy yielded significantly lower free T4 levels, with no changes in TSH or T3 levels. More patients on LT4/T3 had elevated T3 levels, with no significant alterations in the evaluated outcomes. No clear clinical benefit of the studied formulation could be observed. Future trials need to evaluate different formulations and the impact of the combined therapy in select populations with genetic polymorphisms.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Thyroxine
/
Triiodothyronine
/
Hypothyroidism
Type of study:
Controlled clinical trial
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
English
Journal:
Arch. endocrinol. metab. (Online)
Journal subject:
Endocrinology
/
Metabolism
Year:
2016
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Federal do Paraná/BR
Similar
MEDLINE
...
LILACS
LIS