title: Thyroxine softgel capsule in patients with gastric-related T4 malabsorption.
abstract: The key role of an intact gastric acid secretion for subsequent intestinal T4 absorption is supported by an increased requirement of thyroxine in patients with gastric disorders. A better pH-related dissolution profile has been described in vitro for softgel T4 preparation than for T4 tablets. Our study was aimed at comparing softgel and tablet T4 requirements in patients with gastric disorders. A total of 37 patients with gastric-related T4 malabsorption were enrolled, but only 31 (28F/3M; median age = 50 years; median T4 dose = 2.04 μg/kg/day) completed the study. All patients were in long-lasting treatment (>2 years) with the same dose of T4 tablets when treatment was switched to a lower dose of softgel T4 capsules (-17 %; p = 0.0002). Assessment of serum FT4 and TSH was carried out at baseline and after 3, 6, 12, and 18 months after the treatment switch. In more than 2/3 of patients (good-responders n = 21), despite the reduced dose of T4, median TSH values were similar at each time point (p = 0.3934) with no change in FT4 levels. In the remaining patients (poor-responders n = 10), TSH levels were significantly higher at each time point than at baseline (p < 0.0001). To note, in five of them intestinal comorbidity was subsequently detected. Comorbidity associated with poor-responders status was the only significant predictor in multivariate analysis (OR = 11.333). Doses of softgel T4 capsules lower than T4 tablet preparation are required to maintain the therapeutic goal in 2/3 of patients with impaired gastric acid secretion.
authors.affiliation: Department of Medico-surgical Sciences and Biotechnologies, "Sapienza" University of Rome, Latina, Italy.
authors.forename: Maria Giulia
authors.initials: MG
authors.lastname: Santaguida
authors.forename: Camilla
authors.initials: C
authors.lastname: Virili
authors.forename: Susanna Carlotta
authors.initials: SC
authors.lastname: Del Duca
authors.forename: Miriam
authors.initials: M
authors.lastname: Cellini
authors.forename: Ilenia
authors.initials: I
authors.lastname: Gatto
authors.forename: Nunzia
authors.initials: N
authors.lastname: Brusca
authors.forename: Corrado
authors.initials: C
authors.lastname: De Vito
authors.forename: Lucilla
authors.initials: L
authors.lastname: Gargano
authors.forename: Marco
authors.initials: M
authors.lastname: Centanni
mesh_terms: D000328:Adult; D002214:Capsules; D005260:Female; D065570:Gastric Absorption / Q000502:physiology*; D005756:Gastritis / Q000503:physiopathology*; D005782:Gels; D016481:Helicobacter Infections / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013959:Thyroid Diseases / Q000188:drug therapy*; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology
chemical_list: D002214:Capsules; D005782:Gels; D013972:Thyrotropin; D013974:Thyroxine