[Bone marrow depression with peripheral pancytopenia under the treatment with an ampicillin/oxacillin combination (author's transl)].

Under the treatment with ampicillin or oxacillin resp. hematologic changes turn up very rarely except for eosinophilia, in addition it is only granulocytes or platelets alone which are involved in the cases yet published. In the case presented here therapy by an ampicillin/Oxacillin combination induces bone marrow depression with peripheral pancytopenia on a toxic or allergic base.