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Cited by 185Thyroid Disorders and TreatmentsPharmaceutical Economics and PolicyBiosimilars and Bioanalytical Methods

The DOI matches its Crossref record; 23 of the 24 references it cites were found in a registry or an index.

Bioequivalence of Generic and Brand-name Levothyroxine Products in the Treatment of Hypothyroidism

Dong, Betty J.·1997·JAMA: The Journal of the American Medical Association
DOI 10.1001/jama.1997.03540390035032
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Abstract

OBJECTIVE: To compare relative bioavailability of Synthroid, Levoxine (Levoxine has been renamed Levoxyl), and 2 generic levothyroxine sodium preparations. DESIGN: Single-blind (primary investigators blinded), randomized, 4-way crossover trial. SETTING: Ambulatory care. PATIENTS: Twenty-two women with hypothyroidism who were clinically and chemically euthyroid and were receiving levothyroxine sodium, 0.1 or 0.15 mg. INTERVENTIONS: All patients received each of the 4 levothyroxine products for 6-week periods in the same dosage as their prestudy regimen with no washout period. The order of the drug sequences was randomly determined before study initiation. MAIN OUTCOME MEASURES: Area under the curve, time to peak serum concentrations, and peak serum concentrations of thyroxine, triiodothyronine, and free thyroxine index for all 4 products. RESULTS: All data analyses were completed prior to unblinding of the product codes. No significant differences between the 4 products were found in area under the curve or peak serum concentrations of total thyroxine, total triiodothyronine, or free thyroxine index. Although Synthroid produced a more rapid rise in total serum triiodothyronine concentration and a higher total peak serum triiodothyronine concentration than the other products, these differences were not statistically significant (P=.08). The Food and Drug Administration criterion for relative bioequivalence within 90% confidence intervals (0.8-1.25) was demonstrated (P<.05) for all pairs of products. Relative bioequivalence of 0.95 to 1.07 was demonstrated, tighter than the current bioequivalence criterion for oral formulations. CONCLUSIONS: The 4 generic and brand-name levothyroxine preparations studied are different but are bioequivalent by current Food and Drug Administration criteria and are interchangeable in the majority of patients receiving thyroxine replacement therapy. Further investigation is required to determine whether our results are equally applicable to all existing levothyroxine preparations.

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Crossref · 10.1001/jama.1997.03540390035032

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Metadata

Authors
Dong, B. J.
Affiliations
University of California, San Francisco (US)
Corresponding author
Dong, Betty J.
Venue
JAMA: The Journal of the American Medical Association
Publisher
American Medical Association (AMA)
Published
1997-04-16
Volume
277
Issue
15
Pages
1205
ISSN
  • 0002-9955 (ISSN-L)
  • 0098-7484
DOI
10.1001/jama.1997.03540390035032
OpenAlex
W2010621528
Cited by
185
References
24
Citations by year
2024: 1 · 2023: 1 · 2022: 6 · 2021: 3 · 2020: 1 · 2019: 3 · 2018: 4 · 2017: 7 · 2016: 4 · 2015: 4 · 2014: 6 · 2013: 7 · 2012: 7
FWCI
8.39
Type
journal article
Language
en
Open access
closed
Locations
  • JAMA (publishedVersion)
  • PubMed (publishedVersion)
  • DigitalGeorgetown (Georgetown University Library) (submittedVersion)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
  • Social Sciences › Economics, Econometrics and Finance › Economics and Econometrics › Pharmaceutical Economics and Policy
  • Life Sciences › Immunology and Microbiology › Immunology › Biosimilars and Bioanalytical Methods
Keywords
levothyroxine, bioequivalence, generic drugs, brand-name drugs, hypothyroidism, thyroxine replacement, triiodothyronine, free thyroxine index, crossover trial
MeSH terms
Adult, Aged, Drug Industry, Female, Humans, Hypothyroidism, Middle Aged, Therapeutic Equivalency, Thyroid Function Tests, Thyrotropin, Thyroxine, Triiodothyronine, Drugs, Generic, Cross-Over Studies, Area Under Curve

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