It is wise to initiate therapy for adults by administering a single intravenous dose of 3.7 mg/m2 of body surface area (bsa). Thereafter, white-blood-cell counts should be made to determine the patient’s sensitivity to vinblastine sulfate. A simplified and conservative incremental approach to dosage at weekly intervals for adults may be outlined as follows: First dose ........................... 3.7 mg/m2 bsa Second dose ........................... 5.5 mg/m2 bsa Third dose ........................... 7.4 mg/m2 bsa Fourth dose ........................... 9.25 mg/m2 bsa Fifth dose ........................... 11.1 mg/m2 bsa The above-mentioned increases may be used until a maximum dose not exceeding 18.5 mg/m2 bsa for adults is reached. The dose should not be increased after that dose which reduces the white-cell count to approximately 3000 cells/mm3 . In some adults, 3.7 mg/m2 bsa may produce this leukopenia; other adults may require more than 11.1 mg/m2 bsa; and, very rarely, as much as 18.5 mg/m2 bsa may be necessary. For most adult patients, however, the weekly dosage will prove to be 5.5 to 7.4 mg/m2 bsa. When the dose of vinblastine sulfate which will produce the above degree of leukopenia has been established, a dose of 1 increment smaller than this should be administered at weekly intervals for maintenance. Thus, the patient is receiving the maximum dose that does not cause leukopenia. It should be emphasized that, even though 7 days have elapsed, the next dose of vinblastine sulfate should not be given until the white-cell count has returned to at least 4000/mm3. In some cases, oncolytic activity may be encountered before leukopenic effect. When this occurs, there is no need to increase the size of the subsequent doses

15 nM vinblastine inhibit CHO cell proliferation