<prompt> What is the primary toxicity of busulfanLung fibrosisSevere myeloidsupressionCystitisHyperuricaemia  <response>: Busulfan It is highly specific for myeloid elements doses myelosupression occurs; granulocyte precursors being the most sensitive, followed by those of platelets and RBC. It produces little effect on lymphoid tissue and g.i.t. Side effects:- Hyperuricaemia is common; pulmonary fibrosis and skin pigmentation are the specific adverse effects. Sterility also occurs. Uses It is the drug of choice for chronic myeloid leukaemia. Ref:-kd tripathi; pg num:-861 