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

Dong, Betty J.; Hauck, Walter W.; Gambertoglio, John G.; Gee, Lauren; White, John R.; Bubp, Jeff; Greenspan, Francis S.

doi:10.1001/jama.1997.03540390035032

Cited by 142 publications

(28 citation statements)

References 19 publications

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“…Diese Resorptionsstudien wurden zwar vielfach angegriffen, da sie meist mit gesunden Kontrollpersonen durchgeführt worden sind. Dennoch gibt es eindeutige Unterschiede in der Bioverfügbarkeit einzelner Präparate, die zwischen 0,8 und 1,25 schwanken kann und damit klinisch relevant ist [9]. Man kann somit nicht ohne Kontrolle der Schilddrüsenfunktion Levothyroxinpräparate verschiedener Hersteller austauschen.…”

Section: Substitution Von Schilddrüsenhormonenunclassified

Substitution von Schilddrüsenhormonen

Gärtner

Reincke

2008

Internist

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In patients with overt hypothyroidism the substitution with Levothyroxine is mandatory, whereas in patients with subclinical hypothyroidism it is dependent on further clinical signs and symptoms. The main parameter indicating sufficient substitution of Levothyroxine in patients with primary hypothyroidism is TSH, whereas in secondary hypothyroidism it is free T(4). At present Levothyroxine is the preparation of choice to restore euthyroidism in hypothyroid patients because it is assumed that the peripheral conversion from T(4) to T(3) provides the exact amount of T(3) needed by every organ. Intestinal absorption of Levothyroxin is around 80%, but only in acid environment and is significantly decreased by proton-pump inhibitors, antacids, atrophic gastritis and Helicobacter pylori infection. The usual required dosage of Levothyroxine is 1.5 microg/kg of body weight but is increased under these conditions as well as during early childhood and pregnancy, and is decreased in older people. The bioavailability of different Levothyroxin generics might change between 0.8 and 1.25. Therefore, the thyroid function of patients, receiving another brand of Levothyroxine has to be re-checked.

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Section: Substitution Von Schilddrüsenhormonenunclassified

Substitution von Schilddrüsenhormonen

Gärtner

Reincke

2008

Internist

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“…22 The President of Knoll wrote to the journal editor to say that the company had decided to allow publication "first because we gained a better understanding of the importance of supporting academic freedom and the peer review process; and second, we were concerned that intense media speculation about the study's findings and conclusions was being regarded as fact. Clearly the manuscript needed to be published so the study and our concerns about it could be evaluated in the proper context."…”

Section: Other Examplesmentioning

confidence: 99%

Patients’ health or company profits? The commercialisation of academic research

Olivieri

2003

SCI ENG ETHICS

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This paper is a personal account of the events associated with the author's work at the University of Toronto's Hospital for Sick Children on a drug, deferiprone, for the treatment of thalassaemia. Trials of the drug were sponsored by the Canadian Medical Research Council and a drug company which would have been able, had the trials been successful, to seek regulatory approval to market the drug. When evidence emerged that deferiprone might be inadequately effective in a substantial proportion of patients, the drug company issued legal threats when the author proposed informing her patients and the scientific community. Until protests were made by international authorities in her field of research, the hospital and university did not adequately support the author's academic freedom and responsibilities as a medical practitioner. It is argued that underlying cause of this, and of other similar cases, is the political philosophy which is driving the commercialisation of universities and bringing about the deregulation of drug approval procedures. Together these changes constitute a serious threat to the public good.

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“…For example, a manuscript reporting on a trial comparing the bioequivalence of generic and brand levothyroxine products, which had failed to produce the results desired by the sponsor of the study, Boots Pharmaceuticals, was withdrawn because Boots took legal action against the university and the investigators. The actions of Boots, recounted in detail by one of the editors of JAMA, Drummond Rennie, 74 meant that publication of the paper 75 was delayed by about seven years. In a national survey of life-science faculty members in the United States, 20% of faculty members reported that they had experienced delays of more than six months in publication of their work and reasons for not publishing included "to delay the dissemination of undesired results".…”

Section: The Influence Of External Funding and Commercial Interestsmentioning

confidence: 99%