Madagascar Periwinkle contains seventy alkaloids and four are medicinal. It is the source of the chemotherapeutic agents: Vincristine, Vinblastine, Vindesine, and Vinrelbine. Vincristine is used in the treatment of childhood lymphomas, leukemias, neuroblastomas, and rhabdomyosarcomas. Vinblastine is used in the treatment of Hodgkin and non-Hodgkin lymphomas, testicular cancer, and choriocarcinoma. Vincristine and Vinblastine are administered intravenously.