Background: Patients with gastric disorders (H.Pylori related gastritis, gastric atrophy, using proton pump inhibitors) require high dose of thyroxine (T4). Gastric pH has been suggested as critical factor for both dissolution and bioavailability of thyroxine. Softgel thyroxine preparation showed a better in vitro dissolution profile at increasing pH as compared to tablet T4 preparation. Clinical studies suggest a better performance of softgel T4 preparation in treating patients with or without T4 malabsorption. Aim: To analyze whether, in vivo, the better efficacy of softgel preparation may be related to the pH variations of gastric juice. Methods: We enrolled 28 hypothyroid patients treated, for at least 2 years, with a stable dose of tablet T4 (median = 1.65 μg/kg/day) showing a consistent and stable TSH values (<0.8–2.5>mU/l). All patients warranted to take T4 in fasting conditions waiting at least one hour before eating or drinking. All of these patients underwent endoscopy for either dyspepsia or follow up of gastric disorders. Gastric juice has been sampled during endoscopy to measure gastric pH. These patients switched to softgel T4 preparation, titrated to obtain individual serum TSH values as above. Results: Mean gastric juice pH in the whole sample was 2.87 and, based on this value, patients were subdivided in two groups: Group A (n = 20) with a mean pH of 1.69 and Group B (n = 8) showing a mean pH of 5.81, that mirrors a defined reduced gastric acid production. The pH values well correlated with the dose of T4 in both groups (p = 0.0329 and 0.0023). Following the switch to softgel, T4 requirement was the same in 19 out of 20 (95%) of patients with normal pH. On the contrary in 7 out of 8 (88%, p < 0.0001; PPV 95%, Likelihood ratio = 7.6) patients with high gastric pH the requirement of T4 in softgel formulation was significantly reduced. The median reduction in these latter patients was from 1.98 to 1.67 μg/kg/day (–19%). Conclusions: These data indicate that the dose of both tablet and softgel thyroxine correlates with gastric pH and, in hypothyroid patients with disorders or conditions impairing gastric acid secretion, softgel T4 preparation should be the preferred therapeutic choice.
TAILORING THYROXINE TREATMENT: USEFULNESS OF SOFTGEL PREPARATION IN PATIENTS WITH IMPAIRED GASTRIC PH / Virili, Camilla; Cellini, Miriam; Santaguida, MARIA GIULIA; Gargano, Lucilla; Centanni, Marco. - STAMPA. - (2018), pp. 55-55. (Intervento presentato al convegno 41st Annual Meeting of the European Thyroid Association tenutosi a Newcastle upon Tyne).
TAILORING THYROXINE TREATMENT: USEFULNESS OF SOFTGEL PREPARATION IN PATIENTS WITH IMPAIRED GASTRIC PH
Camilla Virili
;Miriam Cellini
;Maria Giulia Santaguida
;Marco Centanni
2018
Abstract
Background: Patients with gastric disorders (H.Pylori related gastritis, gastric atrophy, using proton pump inhibitors) require high dose of thyroxine (T4). Gastric pH has been suggested as critical factor for both dissolution and bioavailability of thyroxine. Softgel thyroxine preparation showed a better in vitro dissolution profile at increasing pH as compared to tablet T4 preparation. Clinical studies suggest a better performance of softgel T4 preparation in treating patients with or without T4 malabsorption. Aim: To analyze whether, in vivo, the better efficacy of softgel preparation may be related to the pH variations of gastric juice. Methods: We enrolled 28 hypothyroid patients treated, for at least 2 years, with a stable dose of tablet T4 (median = 1.65 μg/kg/day) showing a consistent and stable TSH values (<0.8–2.5>mU/l). All patients warranted to take T4 in fasting conditions waiting at least one hour before eating or drinking. All of these patients underwent endoscopy for either dyspepsia or follow up of gastric disorders. Gastric juice has been sampled during endoscopy to measure gastric pH. These patients switched to softgel T4 preparation, titrated to obtain individual serum TSH values as above. Results: Mean gastric juice pH in the whole sample was 2.87 and, based on this value, patients were subdivided in two groups: Group A (n = 20) with a mean pH of 1.69 and Group B (n = 8) showing a mean pH of 5.81, that mirrors a defined reduced gastric acid production. The pH values well correlated with the dose of T4 in both groups (p = 0.0329 and 0.0023). Following the switch to softgel, T4 requirement was the same in 19 out of 20 (95%) of patients with normal pH. On the contrary in 7 out of 8 (88%, p < 0.0001; PPV 95%, Likelihood ratio = 7.6) patients with high gastric pH the requirement of T4 in softgel formulation was significantly reduced. The median reduction in these latter patients was from 1.98 to 1.67 μg/kg/day (–19%). Conclusions: These data indicate that the dose of both tablet and softgel thyroxine correlates with gastric pH and, in hypothyroid patients with disorders or conditions impairing gastric acid secretion, softgel T4 preparation should be the preferred therapeutic choice.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
