Clinical Trial: Drug Etiology of Aplastic Anemia and Related Dyscrasias

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title:

Brief Summary: To determine the role of drugs in the etiology of aplastic anemia, agranulocytosis, and thrombocytopenic purpura. Drugs used in chemotherapy and immunotherapy were excluded.

Detailed Summary:

BACKGROUND:

It was well established that drugs played a role in the etiology of aplastic anemia, agranulocytosis, and thrombocytopenic purpura. In 1985, much of the evidence concerning the relation of exposure to drugs to the risk of the three dyscrasias was based on case reports. Such reports could sometimes be appropriate for raising hypotheses, but they rarely served to establish associations firmly. They could also be subject to selection bias due to a tendency to publish reports only when a dyscrasia followed the use of a drug already under suspicion, and could result in spurious and non-causal associations. Moreover, since denominator populations were not known, case reports could never provide quantitative estimates of associations, either in terms of their magnitude or of the incidence rates attributable to the specific exposures The sparse quantitative information that did exist was of variable quality because of methodological and other difficulties. And while overall incidence rates, within orders of magnitude, could be estimated for the three dyscrasias, there was virtually no acceptably reliable information available on the incidence rates due to specific drugs. Even for well known associations such as aplastic anemia with chloramphenicol, estimates of incidence, if given at all, were imprecise.

The list of drugs incriminated at one time or another in the etiology of each dyscrasia was as long as the pharmacopoeia itself. Based on the clinical evidence, however, there were patterns for each dyscrasia, some of which overlapped. Drugs commonly linked to aplastic anemia included chloramphenicol, phenylbutazone, oxyphenbutazone, sulfonamides, and antithyroid drugs; all of them, except chloramphenicol, were also implicated in the etiology of agranulocytosis, together with phenothiazine derivatives. The same drugs w
Sponsor: National Heart, Lung, and Blood Institute (NHLBI)

Current Primary Outcome:

Original Primary Outcome:

Current Secondary Outcome:

Original Secondary Outcome:

Information By: National Heart, Lung, and Blood Institute (NHLBI)

Dates:
Date Received: May 25, 2000
Date Started: April 1985
Date Completion:
Last Updated: May 12, 2016
Last Verified: May 2000