Most common dose limiting toxicity of chemotherapeutic agent ?

Ans. is 'a' i.e., Myelosuppression "Myelosuppression with depression of both antibody and cell mediated immunity is the single most important dose limiting factor with cytotoxic agents and carries life threatening consequences".Repeated blood monitoring is essential and transfusion of red cells and platelets may be necessary.Cell growth factors e.g. the natural (granulocyte colony stimulating factor (filgrastim) are available to protect against or resolve neutropenia.