Linked Life Data

3821822

Source:http://linkedlifedata.com/resource/pubmed/id/3821822

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1987-4-7
pubmed:abstractText
A change in the formulation of the levothyroxine preparation Synthroid (Flint) in 1982 prompted us to reevaluate the replacement dose of this drug in 19 patients with hypothyroidism. The dose was titrated monthly until thyrotropin levels became normal. The mean replacement dose (+/- SD) was 112 +/- 19 micrograms per day, significantly less (P less than 0.001) than the dose of an earlier formulation--169 +/- 66 micrograms per day--used in a similar study (Stock JM, et al. N Engl J Med 1974; 290:529-33). The fractional gastrointestinal absorption of a tablet of the current formulation is 81 percent, considerably higher than the earlier estimate of 48 percent. Using high-performance liquid chromatographic analysis, we found that the current tablet contains the amount of thyroxine stated by the manufacturer. By measuring the bioavailability of the earlier type of tablet in five patients, we inferred that the strength of the previous tablet had been overestimated. In the present study, the thyrotropin levels of patients on replacement therapy returned to normal when serum triiodothyronine concentrations were not significantly different from those of controls (122 vs. 115 ng per deciliter [1.87 vs. 1.77 nmol per liter]), but when serum thyroxine levels were significantly above those of controls (11.3 vs. 8.7 micrograms per deciliter [145 vs. 112 nmol per liter], P less than 0.001). These findings suggest the possibility that in humans, serum triiodothyronine may play a more important part than serum thyroxine in regulating the serum thyrotropin concentration.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0028-4793
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
316
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
764-70
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Replacement dose, metabolism, and bioavailability of levothyroxine in the treatment of hypothyroidism. Role of triiodothyronine in pituitary feedback in humans.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't