Fatal aplastic anemia due to indomethacin--lymphocyte transformation tests in vitro.

Although indomethacin has been implicated as a possible cause of aplastic anemia on the basis of a few clinical observations, its role has not been definitely established. A case of fatal aplastic anemia is described in which no drugs other than allopurinol and indomethacin were given. Indomethacin was first given four weeks prior to the onset of symptoms. A positive lymphocyte transformation test with indomethacin in vitro further substantiates the potential role of this drug in causing aplastic anemia in a susceptible patient. Fortunately, this seems to be a very rare complication.