Which sequence prevents the heart from trastuzumab and anthracycline toxicity: Electron microscopy study in rats.

e11595 Background: Two effective cytotoxic agents, doxorubicin and trastuzumab, are associated with a potentially life-threatening cardiotoxicity. Currently, these agents are dose and duration limited to circumvent cardiac damage. The current study was designed to investigate the cardiotoxicity aggravated by the timing of administration of trastuzumab and doxorubicin in rats. Methods: A total of 24 mice were randomly assigned to one of four groups. Mice received one of the following treatment drug regimens administered via intraperitoneal injection: (1) 0.9% saline control (n = 6); (2) doxorubicin (5 mg/kg) day 1 then trastuzumab 10 mg/ kg day 15 ( n = 6); (3) trastuzumab 10 mg/ kg day 1 then doxorubicin (5 mg/kg) day 15 ( n = 6); (4) doxorubicin (5 mg/kg) day 1 and trastuzumab 10 mg/ kg day 1 ( n = 6). On the 30th day, all mice were euthanized and the hearts were removed and processed for pathological analysis by electron microscopy. Results: Electron microscopy showed the ultrastructurally normal heart ...