Normally when the white cells have essentially disappeared from the peripheral blood, the white count would have returned to normal. The nadir in the white cell count usually occurs 5 to 10 days after the last treatment with vinblastine. Recovery is usually quite rapid and complete within another 7 to 14 days. If small doses are employed for maintenance therapy, leukopenia may not be clinically significant. If thrombocytopenia does occur, it usually reverses within a few days after termination of treatment.
Vinblastine generally has an insignificant effect on red cell count and hemoglobin.
However, patients with a malignant disease may have anemia even in the absence of antineoplastic therapy. The simultaneous use of several cancer chemotherapy drugs is common practice. Generally drugs with different dose limiting clinical toxicities and different mechanisms of action are selected in order to obtain an increase in therapeutic response without added toxicity. Rarely is it possible to obtain equally as good a response with single antineoplastic treatment. Therefore, vinblastine is often part of polychemotherapy because at the recommended doses it does not cause significant suppression of bone marrow or neuropathy.