Retrospective study of patients switched from tablet formulations to a gel cap formulation of levothyroxine: results of the control switch study
Open accessAbstract
INTRODUCTION: Medication changes involving levothyroxine-either dose titrations or switching formulations-occur frequently in patients with erratic thyroid-stimulating hormone (TSH) levels and persistent hypothyroid symptoms. We investigated whether switching patients from levothyroxine tablets to a gel cap formulation of levothyroxine might reduce dose adjustments and improve tolerability and efficacy outcomes. OBJECTIVES: Primary study objectives included quantifying the percentage of patients achieving TSH levels within a pre-specified range, median dose changes experienced, and the percentage of patients with improved hypothyroid symptom control after switching from levothyroxine tablets to levothyroxine gel caps. METHODS: A retrospective medical chart review was conducted among 99 randomly selected hypothyroid patients who were switched from a tablet to a gel cap formulation of levothyroxine. Patients were required to have been on levothyroxine monotherapy for ≥1 year prior to the medication switch. Data was collected for 6 months pre-switch and up to 6 months post-switch. RESULTS: Of the 99 patients studied, the majority (51.5%) experienced no documented change in TSH status after the switch (P < 0.0001). However, there was a decrease in the mean number of dose changes experienced (1.61 ± 0.96 vs. 0.73 ± 0.96; P < 0.0001). Improved hypothyroid symptom control was reported among 61.6% of patients (61 of 99; P < 0.0001). CONCLUSION: The results of CONTROL Switch support a strategy of switching patients who may experience tolerability or efficacy problems with standard levothyroxine tablets to the levothyroxine gel cap formulation.
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Patients taking soft gel capsules experienced fewer dose adjustments and improved symptoms than patients taking tablets.
“Patients taking soft gel capsules experienced fewer dose adjustments and improved symptoms than patients taking tablets (229).”
From Levothyroxine: conventional and novel drug delivery formulations. (2023) · cites this paper as [229]
It can be postulated that soft gel capsules have superior efficacy over tablets.
“In conclusion, it can be postulated that soft gel capsules have superior efficacy over tablets.”
From Levothyroxine: conventional and novel drug delivery formulations. (2023) · cites this paper as [229]
More than 85% of patients experienced ≤1 dose adjustment post-switch.
“More than 85% of patients experienced ≤1 dose adjustment post-switch.”
From Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report (2017) · cites this paper as [122]
Among patients switched for efficacy reasons (n = 25), 64% experienced improved symptom control.
“Among patients switched for efficacy reasons (n = 25), 64% experienced improved symptom control.”
From Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report (2017) · cites this paper as [122]
In a retrospective study of 99 hypothyroid patients, switching from traditional levothyroxine tablets to levothyroxine gel caps may preclude or reduce the need for levothyroxine dose or formulation changes while improving hypothyroid symptom control in some patients.
“CONTROL Switch, a recent retrospective study involving 99 hypothyroid patients being treated by endocrinologists, suggested that a strategy of switching therapy from the traditional levothyroxine tablets to levothyroxine gel caps may preclude or reduce the need for levothyroxine dose or formulation changes, while improving hypothyroid symptom control, in some patients [122].”
From Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report (2017) · cites this paper as [122]
Switching primarily from branded or generic levothyroxine tablets to levothyroxine gel caps resulted in a significant reduction in dose adjustments (−55%, P < 0.0001).
“switching primarily from either branded or generic levothyroxine tablets to levothyroxine gel caps resulted in:Significant reduction in dose adjustments; −55% (P < 0.0001).”
From Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report (2017) · cites this paper as [122]
Switching from traditional levothyroxine tablets to levothyroxine gel caps resulted in significant improvement in hypothyroid symptom control (+62%, P < 0.0001).
“Significant improvement in hypothyroid symptom control; +62% (P < 0.0001).”
From Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report (2017) · cites this paper as [122]
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- Authors
- Ernst, F. R., Sandulli, W., Elmor, R., Welstead, J., Sterman, A. B., & Lavan, M.
- Corresponding author
- Ernst, Frank R.
- ORCID
- Ernst, Frank R.
- Venue
- Drugs in R&D
- Published
- 2016-12-09
- Volume
- 17
- Issue
- 1
- Pages
- 103-115
- ISSN
- 1174-5886 (ISSN-L)
- 1179-6901
- PMC
- PMC5318319
- OpenAlex
- W2559946799
- Cited by
- 23
- References
- 38
- Citations by year
- 2025: 2 · 2024: 1 · 2023: 3 · 2022: 4 · 2021: 4 · 2020: 4 · 2019: 2 · 2018: 1 · 2017: 2
- FWCI
- 1.67
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Drugs in R&D (publishedVersion, cc-by-nc)
- PubMed Central (publishedVersion, cc-by-nc)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
- Health Sciences › Medicine › Surgery › Thyroid and Parathyroid Surgery
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Cancer Diagnosis and Treatment
- Keywords
- levothyroxine, formulation switching, hypothyroidism, thyroid-stimulating hormone, dose titration, drug tolerability
- MeSH terms
- Administration, Oral, Adult, Aged, Dose-Response Relationship, Drug, Drug Compounding, Female, Gels, Humans, Hypothyroidism, Male, Middle Aged, Retrospective Studies, Tablets, Thyroxine, Young Adult
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