title: A single bolus of high dose levothyroxine (L-T4) as a test in cases of suspected poor compliance to L-T4 therapy.
abstract: BACKGROUND
  Though compliance (or adherence) problems, as well as inappropriate levothyroxine (L-T4) intake (e.g. with meal, other drugs or certain foods that can significantly affect absorption) are very common, the issue is often either not mentioned or even frankly denied by patients.
  
  
  METHODS
  We describe three cases of patients who presented with high TSH (ranging from about 30 to 200 mIU/l), with concomitantly either high, normal or low free thyroxine (FT4), despite treatment with high doses of L-T4. The above mentioned problems with adjustment of L-T4 dose persisted for several months or even years. Coeliac disease screen was negative in all cases. In all these patients administration of a single bolus of L-T4 (1000 μg) or two doses of 1000 μg of L-T4 within 48 h resulted in a quick increase in FT4 (thus confirming proper absorption) and in normalization of TSH within a week. No adverse effects of administration of these high doses of L-T4 were observed.
  
  
  CONCLUSIONS
  Our data support the efficacy, as well as safety of administration of single bolus of high dose L-T4 as a test for possible compliance/adherence problems.
authors.affiliation: Department of Endocrinology and Metabolic Diseases, The Medical University of Lodz, Lodz, Poland ; Polish Mother's Memorial Hospital-Research Institute, Lodz, Poland.
authors.forename: Krzysztof C
authors.initials: KC
authors.lastname: Lewandowski
authors.affiliation: Department of Endocrinology and Metabolic Diseases, The Medical University of Lodz, Lodz, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Dąbrowska
authors.affiliation: Department of Endocrinology and Metabolic Diseases, The Medical University of Lodz, Lodz, Poland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Komorowska-Dudek
authors.affiliation: Department of Endocrinology and Metabolic Diseases, The Medical University of Lodz, Lodz, Poland ; Polish Mother's Memorial Hospital-Research Institute, Lodz, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Lewiński
keywords: Adherence; Compliance; Levothyroxine