Antitumor antibiotics

Question 1

Dactinomycin

Answer 1

Intercalates in DNA;
use: Wilm’s tumor, Ewing’s sarcoma, rhabdomyosarcoma (use for childhood tumors - children ACT out)
Toxicity: myelosuppression

Question 2

Doxorubicin (Adriamycin), daunorubicin

Answer 2

Generate free radicals. Noncovalently intercalate in DNA –> breaks DNA –> decrease replication
use: Hodgkin’s lymphoma; also for myelomas, sarcomas, and solid tumors (breast, ovary, lung)
toxicity: cardiotoxicity*** (dilated cardiomyopathy), myelosuppresion, and alopecia. Toxic to tissues with extravasation.
Dexrazoxane (iron chelating agent) used to prevent cardiotoxicity.

Question 3

Bleomycin

Answer 3

Induces free radical formation, which causes breaks in DNA strands;

use: testicular cancer, Hodgkin’s lymphoma
toxicity: Pulmonary fibrosis***, skin chagnes; minimal myelosuppresion

Question 4

Etoposide

Answer 4

Inhibits topoisomerase II –> Increase DNA degradation

use: small cell carcinoma of the lung and prostate, testicular carcinoma
toxicity: myelosuppresion, GI irritation, alopecia.