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Kaur N, Young VG, Su Y, Suryanarayanan R. Partial Dehydration of Levothyroxine Sodium Pentahydrate in a Drug Product Environment: Structural Insights into Stability. Mol Pharm 2020; 17:3915-3929. [DOI: 10.1021/acs.molpharmaceut.0c00661] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Navpreet Kaur
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota—Twin Cities, 9-177 WDH, 308 Harvard Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Victor G. Young
- Department of Chemistry, X-Ray Crystallographic Laboratory, LeClaire-Dow Chemical Instrumentation Facility, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Yongchao Su
- Pharmaceutical Sciences, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Raj Suryanarayanan
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota—Twin Cities, 9-177 WDH, 308 Harvard Street Southeast, Minneapolis, Minnesota 55455, United States
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Minghetti P, Musazzi UM, Casiraghi A, Rocco P. Old active ingredients in new medicinal products: is the regulatory path coherent with patients' expectations? Drug Discov Today 2020; 25:1337-47. [PMID: 32485225 DOI: 10.1016/j.drudis.2020.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/28/2020] [Accepted: 05/19/2020] [Indexed: 12/19/2022]
Abstract
The rising costs of new medicinal products are a challenge to the economic sustainability of national healthcare systems in ensuring patients' access to therapies. European Union (EU) and US legislators have provided regulatory pathways aimed at simplifying Marketing Authorization (MA) applications for new medicinal products in cases when safety and efficacy profiles can be derived from the data of already-marketed products. In this review, we discuss the different regulatory pathways towards the MA of new medicinal products containing old drug substances and intended to improve the therapeutic value of a treatment, to obtain a new therapeutic indication (drug repositioning), or to ensure the same therapeutic value of a reference product at lower costs.
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3
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Abstract
Oral levothyroxine (LT4) is the standard therapy for patients with hypothyroidism. Oral LT4 is available in several formulations, including tablets, soft gel capsules and oral solution. Multiple brand-name and generic LT4 tablets are available. In the US, the Food and Drug Administration (FDA) has developed a protocol for establishing bioequivalence of LT4 formulations based on serum thyroxine (T4) levels after a single oral dose administered to healthy volunteers. This protocol has been criticized by professional endocrinology associations for using healthy individuals and ignoring serum thyroid-stimulating hormone (TSH) levels. In addition, the protocol did not initially correct for baseline T4 levels, although this was changed in a later version. There are concerns that the FDA's protocol could allow products with clinically significant differences in bioavailability to be declared therapeutically equivalent and interchangeable. Once a generic LT4 has been shown to be bioequivalent to a brand-name LT4, it may be substituted for that brand-name LT4 with no need for dose adjustment or follow-up therapeutic monitoring. Often, the substitution is made by the pharmacy without the physician's knowledge. Even small differences between LT4 formulations can cause significant changes in TSH levels. This may be a particular concern in vulnerable populations, including elderly, pregnant, and pediatric patients. Problems that can be encountered when switching between formulations or when original products are reformulated are discussed in this review. These problems include altered efficacy and adverse events, some of which can be caused by excipients. Patients should be maintained on the same LT4 preparation if possible. If the LT4 preparation is changed, TSH levels should be evaluated and, if necessary, the dose of LT4 adjusted.Funding: Merck.Plain Language Summary: Plain language summary available for this article.
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Affiliation(s)
- Salvatore Benvenga
- Endocrinology Section, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
- Master Program on Childhood, Adolescent and Women's Endocrine Health, University of Messina, Messina, Italy.
- Interdepartmental Program of Molecular and Clinical Endocrinology and Women's Endocrine Health, University Hospital, AOU Policlinico G. Martino, Messina, Italy.
| | - Allan Carlé
- Department of Endocrinology and Internal Medicine, Aalborg University Hospital, Aalborg, Denmark
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Bird ST, Flowers N, Zhao Y, McKean S, Izem R, Wernecke M, Kozlowski S, MaCurdy TE, Kelman JA, Graham DJ. Healthy User Bias in Comparative Safety Studies for Brand-Name vs. Generic Products: The Example of Warfarin. Clin Pharmacol Ther 2019; 106:1037-1045. [PMID: 31062343 DOI: 10.1002/cpt.1498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/21/2019] [Indexed: 11/11/2022]
Abstract
Warfarin was selected as a case study to examine confounding when comparing a product across different manufacturers because it is a narrow therapeutic index drug with prevalent beliefs for brand-name superiority. Medicare beneficiaries aged ≥65 years with atrial fibrillation and an incident outpatient warfarin prescription from July 2006 through July 2015 were included in the study population (N = 746,098). Substantial imbalances were observed between brand-name warfarin and generics for (i) clinical comorbidity, (ii) socioeconomic status, (iii) prescriber specialty, (iv) recent ambulatory and emergent care, (v) drug adherence, (vi) pharmacy setting (e.g., retail, mail-order), and (vii) risk scores for bleeding and thrombosis. Patients receiving brand-name warfarin were healthier than patients receiving generic manufactured warfarin. Utilization of generic warfarin products also differed by geographic region and pharmacy setting. Manufacturer-level comparative-safety studies for causal inference should carefully consider the presence of these imbalances and their potential for introducing healthy user bias.
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Affiliation(s)
- Steven T Bird
- Office of Surveillance and Epidemiology, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | - Yueqin Zhao
- Office of Biostatistics, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | - Rima Izem
- Office of Biostatistics, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | - Steven Kozlowski
- Office of Pharmaceutical Quality, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Thomas E MaCurdy
- Acumen, LLC, Washington, DC, USA.,Department of Economics, Stanford University, Stanford, California, USA
| | - Jeffrey A Kelman
- Centers for Medicare & Medicaid Services, Baltimore, Maryland, USA
| | - David J Graham
- Office of Surveillance and Epidemiology, US Food and Drug Administration, Silver Spring, Maryland, USA
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5
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Concordet D, Gandia P, Montastruc JL, Bousquet-Mélou A, Lees P, Ferran AA, Toutain PL. Authors’ Reply to Nicolas: “Levothyrox® New and Old Formulations: Are they Switchable for Millions of Patients?”. Clin Pharmacokinet 2019; 58:961-963. [PMID: 31161456 PMCID: PMC6584219 DOI: 10.1007/s40262-019-00781-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
| | - Peggy Gandia
- INTHERES, Université de Toulouse, INRA, ENVT, Toulouse, France
| | - Jean-Louis Montastruc
- Service de Pharmacologie Médicale et Clinique, INSERM, UMR 1027, CIC INSERM 1436, Faculté de Médecine, Centre Hospitalier Universitaire de Toulouse, Université de Toulouse, Toulouse, France
| | | | - Peter Lees
- The Royal Veterinary College, University of London, London, UK
| | - Aude A Ferran
- INTHERES, Université de Toulouse, INRA, ENVT, Toulouse, France
| | - Pierre-Louis Toutain
- INTHERES, Université de Toulouse, INRA, ENVT, Toulouse, France.
- The Royal Veterinary College, University of London, London, UK.
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Smallridge RC, Sangaralingham LR, Mwangi R, Kusumoto F, Van Houten H, Bernet V. Comparison of Incident Cardiovascular Event Rates Between Generic and Brand l-Thyroxine for the Treatment of Hypothyroidism. Mayo Clin Proc 2019; 94:1190-1198. [PMID: 31036352 DOI: 10.1016/j.mayocp.2018.11.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/15/2018] [Accepted: 11/01/2018] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To determine whether levothyroxine (L-T4) preparation (generic vs brand) affected hospitalization for cardiovascular events. PATIENTS AND METHODS We performed a retrospective analysis using a large administrative claims database, OptumLabs Data Warehouse, creating two 1-to-1 propensity score-matched cohorts initiating generic or brand L-T4. Patients were followed for a mean of 1.0±1.2 years (range, 0-9.3 years). We included 87,902 propensity score-matched patients (43,951 patients per cohort) initiating generic or brand L-T4. Variables included in matching were age, sex, race/ethnicity, residence region, selected comorbidities, and Charlson-Deyo comorbidity score. Patients with previous use of any thyroid preparation, amiodarone, or lithium were excluded. Primary outcomes were the event rates for hospitalizations for incident atrial fibrillation, myocardial infarction, congestive heart failure, or stroke. RESULTS In the generic L-T4 cohort, 35,242 (80.2%) were women and 7327 (16.7%) were 65 years of age or older; in the brand L-T4 cohort, 34,633 (78.8%) were women and 8092 (18.4%) were 65 years of age or older. We found no differences in event rates (events per 1000 person-years) for 4 outcomes comparing generic and brand L-T4 therapy: (1) atrial fibrillation (1.82 vs 2.19; hazard ratio [HR], 1.22; 95% CI, 0.90-1.65; P=.19); (2) myocardial infarction (2.12 vs 1.83; HR, 0.86; 95% CI, 0.64-1.17; P=.35); (3) congestive heart failure (2.27 vs 2.00; HR, 0.88; 95% CI, 0.66-1.18; P=.41); and (4) stroke (3.10 vs 2.38; HR, 0.77; 95% CI, 0.59-1.00; P=.05). Stratification by age group revealed no differences. CONCLUSION In patients with newly treated hypothyroidism, cardiovascular event rates were similar for generic and brand L-T4.
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Affiliation(s)
| | - Lindsey R Sangaralingham
- Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN; OptumLabs, Cambridge, MA
| | - Raphael Mwangi
- Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN
| | - Fred Kusumoto
- Department of Cardiovascular Medicine, Mayo Clinic, Jacksonville, FL
| | - Holly Van Houten
- Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN; OptumLabs, Cambridge, MA
| | - Victor Bernet
- Division of Endocrinology, Mayo Clinic, Jacksonville, FL
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7
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Mouly S, Roustit M, Bagheri H, Perault-Pochat MC, Molimard M, Bordet R. The French Levothyrox ® crisis: We did the best we could but…. Therapie 2019; 74:431-5. [PMID: 30737052 DOI: 10.1016/j.therap.2019.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 11/29/2018] [Accepted: 01/15/2019] [Indexed: 11/22/2022]
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8
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Gupta D, Kumar S, Seyoum B. Blister-packed levothyroxine sodium or bottle-packed levothyroxine sodium. J Basic Clin Physiol Pharmacol 2018; 29:309-311. [PMID: 29949511 DOI: 10.1515/jbcpp-2017-0166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 04/07/2018] [Indexed: 06/08/2023]
Affiliation(s)
- Deepak Gupta
- Clinical Assistant Professor, Anesthesiology, Wayne State University/Detroit Medical Center, Box No 162, 3990 John R, Detroit, MI 48201, USA
| | - Sarwan Kumar
- Internal Medicine, Wayne State University, Detroit, Michigan, USA
| | - Berhane Seyoum
- Internal Medicine, Division of Endocrinology, Wayne State University, Detroit, Michigan, USA
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Abstract
IN BRIEF As more patents on biological medicines expire, increased numbers of biologic copies, referred to as "biosimilars," will likely become available in the United States in the coming years. With greater availability and the drive for health care savings, the use of biosimilars and of "follow-on" biological products is likely to increase in routine clinical practice. Health care practitioners need to be fully aware of these products and accompanying considerations if they are to make informed decisions together with their patients.
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Affiliation(s)
- Curtis Triplitt
- Texas Diabetes Institute, University Health System, University of Texas Health Science Center, San Antonio, TX
| | - Debbie Hinnen
- Memorial Hospital Outpatient Diabetes Clinic, University of Colorado Health, Colorado Springs, CO
| | - Virginia Valentine
- College of Nursing, School of Medicine, and College of Pharmacy, University of New Mexico, Albuquerque, NM
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Romanelli RJ, Nimbal V, Dutcher SK, Pu X, Segal JB. Provider and Patient Determinants of Generic Levothyroxine Prescribing: An Electronic Health Records-Based Study. Ann Pharmacother 2017; 51:640-648. [PMID: 28425295 DOI: 10.1177/1060028017705393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Despite the availability of generic levothyroxine products for more than a decade, uptake of these products is poor. OBJECTIVE We sought to evaluate determinants of generic prescribing of levothyroxine. METHODS In a cross-sectional analysis of electronic health records data between 2010 and 2013, we identified adult patients with a levothyroxine prescription from a primary-care physician (PCP) or endocrinologist. We used mixed-effect logistic regression models with random intercepts for prescribing provider to examine predictors of generic levothyroxine prescribing. Models include patient, prescription, and provider fixed-effect covariates. Odds ratios (ORs) and 95% CIs were generated. Between-provider random variation was quantified by the intraclass correlation coefficient (ICC). RESULTS Study patients (n = 63 838) were clustered among 941 prescribing providers within 25 ambulatory care clinics. The overall prevalence of generic prescribing of levothyroxine was 73%. In the multivariable mixed-effect model, patients were significantly less likely to receive generic levothyroxine from an endocrinologist than a PCP (OR = 0.43; 95% CI = 0.33-0.55; P < 0.001). Women were less likely to receive generic levothyroxine than men from endocrinologists (OR = 0.68; 95% CI = 0.59-0.78; P < 0.001) but not from PCPs. Between-provider variation in generic prescribing was 18.3% in the absence of fixed-effect covariates and could be explained marginally by patient, prescription, and provider factors (ICC = 15.9%). CONCLUSIONS Generic levothyroxine prescribing differed by PCPs and endocrinologists. Residual variation in generic prescribing, after accounting for measurable factors, indicates the need for provider interventions or patient education aimed at improving levothyroxine generic uptake.
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Affiliation(s)
| | - Vani Nimbal
- 1 Palo Alto Medical Foundation Research Institute, Palo Alto, CA, USA
| | - Sarah K Dutcher
- 2 Office of Generic Drugs, United States Food and Drug Administration, Silver Springs, MD, USA
| | - Xia Pu
- 2 Office of Generic Drugs, United States Food and Drug Administration, Silver Springs, MD, USA
| | - Jodi B Segal
- 3 Johns Hopkins University School of Medicine, Baltimore, MD, USA
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11
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Gottwald-Hostalek U, Uhl W, Wolna P, Kahaly GJ. New levothyroxine formulation meeting 95-105% specification over the whole shelf-life: results from two pharmacokinetic trials. Curr Med Res Opin 2017; 33:169-174. [PMID: 27718637 DOI: 10.1080/03007995.2016.1246434] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Small levothyroxine (L-T4) dose changes can lead to significant clinical effects. To ensure thyroid hormone levels are safely maintained, authorities are increasingly adopting stricter potency specifications for L-T4, the most stringent of these being 95-105% of the labeled dose over the whole shelf-life. Levothyroxine sodium (Euthyrox, Eutirox, Lévothyrox ) has been reformulated, and two studies performed, to ensure bioequivalence to the currently marketed formulation and dosage form proportionality of the new formulation. METHODS The bioequivalence study was an open-label, randomized, single-dose, two-period, two-sequence crossover comparing the highest dosage strengths of the currently marketed and the new L-T4 formulation at a total dose of 600 μg. The dosage form proportionality study was an open-label, randomized, three-period, six-sequence crossover, comparing 50 μg, 100 μg, and 200 μg L-T4 tablets, at a total dose of 600 μg. Blood samples were taken at predefined time intervals. Primary outcomes were area under the curve (AUC) and maximum concentration (Cmax) of thyroxine (T4) in plasma. RESULTS In the bioequivalence study, comparing the T4 profiles for the new and current formulation of L-T4, the geometric least square mean ratio of the baseline-adjusted AUC0-72,adj was 99.3% (90% confidence interval [CI]: 95.6-103.2) and the Cmax,adj was 101.7% (90% CI: 98.8-104.6). Bioequivalence was established if the 90% CI lay within the predefined 0.9-1.11 limits. In the dosage form proportionality study, pairwise comparisons ranged from 99.3% to 104.8%, and all 95% CIs were within the predefined CI range (0.8-1.25): the three dose strengths were dosage form proportional. CONCLUSIONS The new formulation of L-T4 meets the most stringent potency specification guidelines, and has been demonstrated to be bioequivalent to the current formulation and to show dosage form proportionality. The new formulation will enable patients to receive a dose fine tuned to their medical needs, contributing to improved safety in the use of L-T4.
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Affiliation(s)
| | | | | | - George J Kahaly
- c Johannes Gutenberg University Medical Center , Mainz , Germany
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12
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Patel MS, Day SC, Halpern SD, Hanson CW, Martinez JR, Honeywell S, Volpp KG. Generic Medication Prescription Rates After Health System-Wide Redesign of Default Options Within the Electronic Health Record. JAMA Intern Med 2016; 176:847-8. [PMID: 27159011 PMCID: PMC7240800 DOI: 10.1001/jamainternmed.2016.1691] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Mitesh S Patel
- Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania2Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Susan C Day
- Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Scott D Halpern
- Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - C William Hanson
- Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Joseph R Martinez
- Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Steven Honeywell
- Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Kevin G Volpp
- Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania2Perelman School of Medicine, University of Pennsylvania, Philadelphia
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Jonklaas J, Bianco AC, Bauer AJ, Burman KD, Cappola AR, Celi FS, Cooper DS, Kim BW, Peeters RP, Rosenthal MS, Sawka AM. Guidelines for the treatment of hypothyroidism: prepared by the american thyroid association task force on thyroid hormone replacement. Thyroid 2014; 24:1670-751. [PMID: 25266247 PMCID: PMC4267409 DOI: 10.1089/thy.2014.0028] [Citation(s) in RCA: 928] [Impact Index Per Article: 92.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND A number of recent advances in our understanding of thyroid physiology may shed light on why some patients feel unwell while taking levothyroxine monotherapy. The purpose of this task force was to review the goals of levothyroxine therapy, the optimal prescription of conventional levothyroxine therapy, the sources of dissatisfaction with levothyroxine therapy, the evidence on treatment alternatives, and the relevant knowledge gaps. We wished to determine whether there are sufficient new data generated by well-designed studies to provide reason to pursue such therapies and change the current standard of care. This document is intended to inform clinical decision-making on thyroid hormone replacement therapy; it is not a replacement for individualized clinical judgment. METHODS Task force members identified 24 questions relevant to the treatment of hypothyroidism. The clinical literature relating to each question was then reviewed. Clinical reviews were supplemented, when relevant, with related mechanistic and bench research literature reviews, performed by our team of translational scientists. Ethics reviews were provided, when relevant, by a bioethicist. The responses to questions were formatted, when possible, in the form of a formal clinical recommendation statement. When responses were not suitable for a formal clinical recommendation, a summary response statement without a formal clinical recommendation was developed. For clinical recommendations, the supporting evidence was appraised, and the strength of each clinical recommendation was assessed, using the American College of Physicians system. The final document was organized so that each topic is introduced with a question, followed by a formal clinical recommendation. Stakeholder input was received at a national meeting, with some subsequent refinement of the clinical questions addressed in the document. Consensus was achieved for all recommendations by the task force. RESULTS We reviewed the following therapeutic categories: (i) levothyroxine therapy, (ii) non-levothyroxine-based thyroid hormone therapies, and (iii) use of thyroid hormone analogs. The second category included thyroid extracts, synthetic combination therapy, triiodothyronine therapy, and compounded thyroid hormones. CONCLUSIONS We concluded that levothyroxine should remain the standard of care for treating hypothyroidism. We found no consistently strong evidence for the superiority of alternative preparations (e.g., levothyroxine-liothyronine combination therapy, or thyroid extract therapy, or others) over monotherapy with levothyroxine, in improving health outcomes. Some examples of future research needs include the development of superior biomarkers of euthyroidism to supplement thyrotropin measurements, mechanistic research on serum triiodothyronine levels (including effects of age and disease status, relationship with tissue concentrations, as well as potential therapeutic targeting), and long-term outcome clinical trials testing combination therapy or thyroid extracts (including subgroup effects). Additional research is also needed to develop thyroid hormone analogs with a favorable benefit to risk profile.
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Affiliation(s)
| | - Antonio C. Bianco
- Division of Endocrinology, Rush University Medical Center, Chicago, Illinois
| | - Andrew J. Bauer
- Division of Endocrinology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Kenneth D. Burman
- Endocrine Section, Medstar Washington Hospital Center, Washington, DC
| | - Anne R. Cappola
- Division of Endocrinology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Francesco S. Celi
- Division of Endocrinology, Virginia Commonwealth University School of Medicine, Richmond, Virginia
| | - David S. Cooper
- Division of Endocrinology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Brian W. Kim
- Division of Endocrinology, Rush University Medical Center, Chicago, Illinois
| | - Robin P. Peeters
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - M. Sara Rosenthal
- Program for Bioethics, Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Anna M. Sawka
- Division of Endocrinology, University Health Network and University of Toronto, Toronto, Ontario, Canada
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14
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Abstract
Thyroid hormone deficiency can have important repercussions. Treatment with thyroid hormone in replacement doses is essential in patients with hypothyroidism. In this review, we critically discuss the thyroid hormone formulations that are available and approaches to correct replacement therapy with thyroid hormone in primary and central hypothyroidism in different periods of life such as pregnancy, birth, infancy, childhood, and adolescence as well as in adult patients, the elderly, and in patients with comorbidities. Despite the frequent and long term use of l-T4, several studies have documented frequent under- and overtreatment during replacement therapy in hypothyroid patients. We assess the factors determining l-T4 requirements (sex, age, gender, menstrual status, body weight, and lean body mass), the major causes of failure to achieve optimal serum TSH levels in undertreated patients (poor patient compliance, timing of l-T4 administration, interferences with absorption, gastrointestinal diseases, and drugs), and the adverse consequences of unintentional TSH suppression in overtreated patients. Opinions differ regarding the treatment of mild thyroid hormone deficiency, and we examine the recent evidence favoring treatment of this condition. New data suggesting that combined therapy with T3 and T4 could be indicated in some patients with hypothyroidism are assessed, and the indications for TSH suppression with l-T4 in patients with euthyroid multinodular goiter and in those with differentiated thyroid cancer are reviewed. Lastly, we address the potential use of thyroid hormones or their analogs in obese patients and in severe cardiac diseases, dyslipidemia, and nonthyroidal illnesses.
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Affiliation(s)
- Bernadette Biondi
- Department of Clinical Medicine and Surgery (B.B.), University of Naples Federico II, 80131 Naples, Italy; and Washington Hospital Center (L.W.), Washington, D.C. 20010
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15
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Abstract
Thyroid diseases affect up to 5% of all pregnancies. Adverse pregnancy and neonatal outcomes are increased by maternal thyroid disease and adequate treatment is thought to reduce these risks. Hypothyroidism is commonly treated with levothyroxine, with pregnancy increasing levothyroxine requirements in most women treated for hypothyroidism. Hyperthyroidism is often treated with antithyroid drugs in pregnancy. However, they are not completely safe to use during pregnancy as methimazole increases risk of neonatal malformations and propylthiouracil increases risk of maternal hepatotoxicity. Propylthiouracil is recommended to be used during the first trimester and switch to methimazole is recommended thereafter to reduce risk of hepatotoxicity. The treatment goal for hypothyroidism and hyperthyroidism is to achieve euthyroidism quickly and maintain it throughout pregnancy. Autoimmune thyroiditis and isolated maternal hypothyroxinemia do not currently warrant treatment during pregnancy, unless hypothyroidism ensues. Treatment of thyroid nodules and differentiated thyroid cancer can generally be safely postponed until after delivery.
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Affiliation(s)
- Tuija Männistö
- a National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Division of Intramural Population Health Research, Epidemiology Branch, Rockville, MD, 20852, USA
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