[Benzylpenicillin-induced leucopenia in subacute bacterial endocarditis (author's transl)].

In the high-dose benzylpenicillin treatment of subacute bacterial endocarditis leucopenia can develop in rare cases. Often it is paralleled by anemia, sometimes also by a decrease in the number of platelets. Myalgia, gastric discomfort, or a sore threat deserve interest as premonitory symptoms. In every case this treatment inevitably needs through hematologic control.