Je joins en fin un article qui ne date pas d'hier (toutes mes excuses il est en anglais. La conclusion est qu'un des tests avait 18% de faux positifs alors que d'autres tests n'en avaient que tres peu). j'ai trouvé sur le web des questions sur la
méthadone pour savoir si elle pouvait aussi rendre le test de grossesse faussement négatif (malgré une grossesse confirmée par la suite)= là aussi experiences vecues à l'appui.
Amicalement
Prescirpteur
Author(s):
Horwitz CA
Maslansky R
Waldinger R
Cabrera H
Ward PC
Source citation:
Journal of Reproduction and Fertility 33(3): 489-493. June 1973,
Abstract:
The results of studies on 309 samples of urine from 103 patients taking
methadone as tested by 4 commercially available pregnancy tests are reported. Urine specimens were subjected to 2 hemagglutination-inhibition tube bests (UCG and Pregnosticon) and 2 latex agglutination-inhibition slide tests (Cravindex and Pregnosticon). Thin-layer chromatography was done on Silpate-22 plates and various narcotics and other drugs were identified by standard procedures. Most of the problem specimens were from patients on high doses of
methadone, 100 mg or more a day. False positive or inconclusive test results were recorded with the Gravindex slide test on 18% of specimens and with the Pregnosticon slide test on 3.6% of specimens. Using the tube hemagglutination tests, only a single false positive test was obtained from 309 specimens. Results suggest that
methadone, or its metabolites could be resonsible for the inhibition of latex particle agglutination giving the false positive results. Associated proteinuria in 20% of urine specimens may also have been a factor. Since completion of this study in 1971, a new Gravindex test has become available, It may eliminate the false positive tests in most cases. The accuracy was 99.7% for the Pregnosticon and UCG tube tests, 96.4% for the Pregnosticon slide test, and 81.2% for the Gravindex slide test.
Keywords:
Prospective Studies
Pregnancy Tests, Immunologic
Evaluation
Studies
Research Methodology
Pregnancy Tests
Laboratory Procedures
Laboratory Examinations and Diagnoses
Examinations and Diagnoses