Leukopenia and granulocytopenia after oxacillin therapy.

Two cases of granulocytopenia and leukopenia developing after high-dosage oxacillin therapy given intravenously are described. One patient developed leukopenia and granulocytopenia after 17 days of therapy. The conditions were reversible when oxacillin therapy was discontinued. In the other case, the adverse reaction developed within 48 hours after therapy began and the patient died from heart failure. Leukopenia and granulocytopenia as adverse effects of oxacillin therapy should be kept in mind, especially when high dosages are used.