DNA interactive agents can be subdivided into topoisomerase inhibitors and strand-breakage agents. The latter group (also called antitumor antibiotics), which includes bleomycin binds reduced Fe2+ and produces single and double-strand DNA
breaks by free radical formation. And so gaps, deletions and DNA fragments occur.
Bleomycin is one of the few drugs in antitumor treatment that does not cause myelosuppression as an adverse effect. However, bleomycin has serious toxicities like pulmonary fibrosis, fever, and dermatological problems. Hypersensitivity is another severe but not very common side effect, which strongly depends on the dose and the pharmacokinetics in the patient. Bleomycin is being used in the treatment of testicular cancer.
I Bleomycin is easily taken up by cells via active transport. II Repeated thorax X-rays need to be made and lung function needs to be tested during and after bleomycin treatment.
Extra info: Bleomycin is a large molecule and penetrates cell membranes poorly via a bleomycin-binding membrane protein. Intensive checks of lung function are necessary in order to prevent irreversible lung damage.