Treating primary hypothyroidism with weekly doses of levothyroxine: a randomized, single-blind, crossover study.
OBJECTIVE
Compliance to levothyroxine treatment in hypothyroidism is compromised by daily schedule, and a weekly dose may be an alternative.


METHODS
This was a randomized, crossover study. Fourteen females were assigned to daily or weekly doses of LT4. After six weeks, they switched regimens. Thyroid parameters were measured at baseline, and after 42 and 84 days. Echocardiogram and hyperthyroidism symptoms were evaluated before and four hours after LT4 intake.


RESULTS
In the weekly dose treatment, fT4 levels were higher after taking LT4, and lower seven days after the last dose; by the 6(th) week there was a small decrease in T3 levels. TSH remained unchanged and there were no hyperthyroidism symptoms or echocardiographic manifestations.


CONCLUSIONS
Weekly dose leads to transient increases in fT4, without hyperthyroidism or cardiac symptoms. That approach seems to be a safe alternative for the treatment of hypothyroidism.
Serviço de Endocrinologia e Metabologia, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil.
Andressa
A
Bornschein
Gilberto
G
Paz-Filho
Hans
H
Graf
Gisah A de
GA
Carvalho
D000328:Adult; D018592:Cross-Over Studies; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000188:drug therapy*; D055118:Medication Adherence; D008875:Middle Aged; D016037:Single-Blind Method; D013972:Thyrotropin / Q000097:blood / Q000187:drug effects; D013974:Thyroxine / Q000008:administration & dosage* / Q000097:blood / Q000187:drug effects; D013997:Time Factors; D016896:Treatment Outcome
D013972:Thyrotropin; D013974:Thyroxine