Antineoplastic agents bone marrow

Intensive intermittent schedules of drug treatment should allow time for recovery from the acute toxic effects of antineoplastic agents, primarily bone marrow toxicity. The use of non-myelosuppressive agents can be considered during the recovery period, especially for treatment of fast-growing cancers. 

Veno-occlusive disease (VOD) differs from Budd-Chiari syndrome in that it consists of occlusive fibrosis of the small intrahepatic veins. VOD may present as either an acute form with sudden ascites, liver enlargement and rapidly rising bilirubin, or as a chronic form with fibrosis and cirrhosis. One of the main causes of VOD is the use of cyclophosphamide or alkalating agents during conditioning for bone marrow transplantation, where it occurs in up to 20% of cases. Other causes include irradiation, antineoplastic drugs, pyrrolizidine alkaloids and alcohol. 

Aside from its antineoplastic activity, methotrexate also has been used with benefit in the therapy of psoriasis. Additionally, it inhibits cell-mediated immune reactions and is employed as an immunosuppressive agent to suppress graft-versus-host disease in allogenic bone marrow and organ... 

Busulfan is no longer used clinically as an antineoplastic agent. It is now used to destroy the myeloid cell line prior to an allogeneic bone marrow transplant for leukemia. 

Allopurinol inhibits the enzymatic inactivation of mercaptopurine and its derivative azathio-prine by xanthine oxidase. Thus, when allopurinol is used concomitantly with oral mercaptopurine or azathioprine, dosage of the antineoplastic agent must be reduced by 25-33% (see Chapters 38 and 51). This is of importance when treating gout in the transplant recipient. The risk of bone marrow suppression also is increased when allopurinol is administered with cytotoxic agents that are not metabolized by xanthine oxidase, particularly cyclophosphamide. 

---