Daily requirement of softgel thyroxine is independent from gastric juice pH

Virili, Camilla; Capriello, Silvia; Stramazzo, Ilaria; Brusca, Nunzia; Santaguida, Maria Giulia; Gargano, Lucilla; Bagaglini, Maria Flavia; Bruno, G; Severi, Carola; Centanni, Marco

doi:10.3389/fendo.2022.1002583

Cited by 5 publications

(3 citation statements)

References 42 publications

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“…These data were confirmed in patients with impaired gastric acidic output ( 15 ). Recently, the independence of the LT4-C requirement on gastric juice pH in vivo has been shown ( 9 ). In the present study, the better performance of LT4-C compared to the tablet preparation is evident, even after excluding patients with known features interfering with thyroxine treatment.…”

Section: Discussionmentioning

confidence: 99%

“…While tablet preparation requires a disintegration/dissolution process to release the active ingredient in the stomach, the liquid solution does not require specific steps, and capsules are rapidly melted in the gastric lumen (5)(6)(7). This means that while the performance of LT4-T closely depends on the characteristic of the gastric environment, the pharmacokinetics of liquid and cap preparations are less likely to be impaired by gastric status (8,9). Several studies demonstrated that LT4-T efficacy can be reduced by food intake, medications and gastric disorders influencing gastric pH, thus decreasing LT4 bioavailability (i.e., Helicobacter pylori gastritis, atrophic gastritis, proton-pump inhibitors, aluminium-containing antacids, calcium carbonate, sucralfate, etc.)…”

Section: Introductionmentioning

confidence: 99%

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Analysis of dose–TSH response effect of levothyroxine soft-gel formulation

Trimboli,

Piticchio,

Dadda

et al. 2024

Front. Endocrinol.

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BackgroundHypothyroidism is treated with daily levothyroxine (LT4). In recent years, soft gel caps of LT4 (LT4-C) have been commercialized, and their performance has been optimized. Since guidelines recommend dose LT4 according to the tablet preparation efficacy, the present study was undertaken to obtain data about the daily requirement, normalized per body weight, of LT4-C.MethodsPatients undergoing LT4-C after total thyroidectomy and radioiodine treatment for differentiated thyroid carcinoma were selected. There was no specific indication of suppression of TSH (i.e., <0.5 or <0.1 mIU/L). Patients were required to maintain a stable LT4 dose during the study period. Patients with interfering factors were excluded from this study.ResultsThirty patients were enrolled (18 females and 12 males; median age, 50 years; median body weight, 71 kg; median LT4-C dose, 1.71 µg/kg/day). The analysis of patient age did not reveal any differences. The LT4-C dose correlated with free-T4 p = 0.03), but not with TSH (p = 0.42) and free-T3 (p = 0.13). TSH was <1.0 mIU/L in 90% of the cases. The LT4-C dose–TSH response effect was analysed by probit regression model: the probability to achieve TSH <1.0 mIU/l was 99% with a dose of 1.84 (95%CI 1.57–2.12) µg/kg/day, 75% with a dose of 1.38 µg/kg/day (95%CI 1.17–1.59), and 50% with a dose of 1.20 (95%CI 0.96–1.43). At ROC curve analysis, the most accurate cut-off of LT4-C dose to achieve TSH <1.0 mIU/l was 1.53 ug/kg/day with 70% sensitivity and 100% specificity.ConclusionsAthyreotic patients can be initially treated with an LT4-C dose lower than previously stated. Therefore, further prospective studies are warranted.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of dose–TSH response effect of levothyroxine soft-gel formulation

Trimboli,

Piticchio,

Dadda

et al. 2024

Front. Endocrinol.

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“…Following the switch from tablet to soft capsule in 28 patients with hypothyroidism on stable LT4 tablet doses, the LT4 requirement was the same in all 17 patients with normal gastric pH (median pH: 1.52), while in patients with high gastric pH (median pH: 5.02), the requirement for LT4 soft capsules was significantly reduced in 10 out of 11 patients. 15 …”

Section: Introductionmentioning

confidence: 99%

Efficacy of Levothyroxine Sodium Soft Gelatin Capsules in Thyroidectomized Patients Taking Proton Pump Inhibitors: An Open-Label Study

Sachmechi,

Lucas,

Stonesifer

et al. 2023

Thyroid®

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Background: Treatment with proton pump inhibitors (PPIs) and antacids affects the gastrointestinal absorption of levothyroxine sodium (LT4) tablets. Patients with hypothyroidism taking LT4 and PPIs or antacids, thus, require appropriate monitoring. The objective of this study was to determine whether a soft gelatin capsule of LT4 (Tirosint ® ) would obviate the effect of PPIs on LT4 absorption. The objective was achieved by assessing the effects of a switch from a conventional LT4 tablet form to the same dose as soft capsules in thyroidectomized patients on treatment with LT4 and PPIs. Methods: Patients with history of hypothyroidism due to total thyroidectomy on stable treatment with LT4 tablets, and with gastrointestinal disease treated with PPIs, were switched to a 12-week treatment with Tirosint at the same dose of the LT4 tablets, while maintaining treatment with PPIs. Serum thyrotropin (TSH) levels were the primary endpoint of the study. Secondary efficacy endpoints were: serum levels of free thyroxine (fT4), total thyroxine (TT4), free triiodothyronine (fT3), total triiodothyronine (TT3), creatine-phosphokinase (CPK), sex-hormone binding globulin, ferritin, angiotensin converting enzyme, and a lipid panel. Results: Forty-seven patients (36 females and 11 males, mean age 55.4 years) were enrolled and 45 of them completed the study (2 patients withdrew consent). During treatment with Tirosint, mean TSH levels demonstrated a statistically significant decrease (mean changes from baseline: −0.32 mIU/L at week 6 and −0.68 mIU/L at week 12) and concomitant increases in thyroid hormone (TH) levels from baseline to week 12, which were statistically significant for fT3 and TT3 (mean changes from baseline: 0.26 pmol/L and 0.10 nmol/L, respectively). Significant decreases of serum low-density lipoprotein, total cholesterol, and CPK levels were observed at week 12. No signs/symptoms arose during the study that could be specifically correlated to either hypo- or hyperthyroidism. Conclusions: In thyroidectomized patients taking PPIs and replacement LT4, a switch from conventional LT4 tablets to LT4 soft capsules at the same dose was associated with a significant decrease in TSH and increase in TH, indicating that LT4 absorption may be less affected by PPIs when given in the form of soft capsules. Clinical Trial Registration: NCT03094416.

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