Bleomycin toxicity affects which organ predominantly:March 2011

Ans. B: LungsToxicity of Bleomycin is nausea, vomiting, dermographia, scleroderma like changes in skin, pneumonitis and occasionally pulmonary fibrosis.It is rarely a myelosuppressnatBleomycinIt is a glycopeptide antibiotic produced by the bacterium Streptomyces veicillus.Bleomycin refers to a family of structurally related compounds.When used as an anticancer agent, the chemotherapeutical forms are primarily bleomycin A2 and B2.It works by causing breaks in DNA.The drug is used in the treatment of Hodgkin's lymphoma (as a component of the ABVD regimen), squamous cell carcinomas, and testicular cancer, as well as in the treatment of plantar was and as a means of effecting pleurodesisBleomycin acts by induction of DNA strand breaks.DNA cleavage by bleomycin depends on oxygen and metal ions, at least in vitro.Therefore bleomycin is used in combination with doxorubicin in Hodgkins lymphoma, as they have additive and complementary effects on the DNA, since doxorubicin acts by intercalating between DNA strands, and also acts on topoisomerase II enzyme thus relaxing the topoisomerase complexesThe most serious complication of bleomycin is pulmonary fibrosis and impaired lung function.It has been suggested that bleomycin induces sensitivity to oxygen toxicityOther side effects include fever, rash, dermatographism, hyperpigmentation, alopecia (hair loss) and Raynaud's phenomenon (discoloration of fingers and toes).