title: Reversible normalisation of serum TSH levels in patients with autoimmune atrophic gastritis who received L-T4 in tablet form after switching to an oral liquid formulation: a case series.
abstract: BACKGROUND
  L-thyroxine (L-T4) malabsorption is a potential concern in patients with autoimmune atrophic gastritis.
  
  
  METHODS
  We evaluated five patients with autoimmune gastritis, who showed high serum thyrotropin (TSH) levels (in the hypothyroid range) while in therapy with L-T4 in tablet. All patients were switched to receive an oral L-T4 liquid formulation maintaining the same dosage.
  
  
  RESULTS
  In all patients who received L-T4 in tablet form after switching to an oral liquid formulation with the same L-T4 dosage, TSH circulating levels were normalized. In four patients who were switched back again to receive L-T4 in tablets, maintaining the dosage, TSH levels worsened again reaching levels in the hypothyroid range.
  
  
  CONCLUSIONS
  The fact that the change from tablets to liquid oral formulation normalised serum TSH levels, and that switching back to tablets caused thyrotropin levels to worsen, leads us to believe that absorption of L-T4 is greater with oral liquid formulations in these patients. These results suggest that the L-T4 oral liquid formulation could circumvent the pH alteration resulting from atrophic gastritis.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Savi 10, 56126, Pisa, Italy.
authors.forename: Poupak
authors.initials: P
authors.lastname: Fallahi
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Savi 10, 56126, Pisa, Italy.
authors.forename: Silvia Martina
authors.initials: SM
authors.lastname: Ferrari
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Savi 10, 56126, Pisa, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Ruffilli
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Savi 10, 56126, Pisa, Italy. alessandro.antonelli@med.unipi.it.
authors.forename: Alessando
authors.initials: A
authors.lastname: Antonelli
mesh_terms: D000284:Administration, Oral; D001327:Autoimmune Diseases / Q000150:complications / Q000378:metabolism*; D002626:Chemistry, Pharmaceutical; D015331:Cohort Studies; D005260:Female; D005757:Gastritis, Atrophic / Q000150:complications / Q000378:metabolism*; D020249:Hormone Replacement Therapy / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007037:Hypothyroidism / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D012189:Retrospective Studies; D013607:Tablets; D013972:Thyrotropin / Q000378:metabolism*; D013974:Thyroxine / Q000008:administration & dosage* / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
chemical_list: D013607:Tablets; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine
keywords: Gastritis; Hypothyroidism; L-thyroxine; Liquid L-thyroxine