Trastuzumab all are true EXCEPT:

Causes upregulation of HER2/neu REF: Lippincott's pharmacology 6th edition 653, Goodman & Gillman's 11'1' edition page 901, http://en.wikipedia.org/wiki/Trastuzumab "It has been suggested that trastuzumab induces some of its effect by downregulation of HER2/neu not upregulation" Trastuzumab: Herceptin (Trastuzumab) is a humanized antibody directed against the HER-2 antigen that is overexpressed on the tumor cell surface in approximately 25% of breast cancer patients. Trastuzumab is approved as intravenous infusion in HER2/neu overexpressing metastatic breast cancer in combination with paclitaxel as initial treatment or as monotherapy following chemotherapy relapse. Trastuzumab also is synergistic with other cytotoxic agents, but only in HER2/neuoverexpressing cancers. Trastuzumab is a humanized monoclonal antibody that binds to the domain IV of the extracellular segment of the HER2/neu receptor It has been suggested that trastuzumab induces some of its effect by downregulation of HER2/ neu Herceptinus e is associated withinfusion-relatedhypotension , flushing andbronchoconstriction, and skin rash but no bone marrow toxicity Herceptin appears to sensitize patients to cardiotoxicity, an impoant concern in patients also receiving doxorubicin.