whether or not you need another loading dose if your treatment has been delayed
 

discussed in the following article

http://opp.sagepub.com/content/early....full.pdf+html





Trastuzumab therapy in breast cancer: To reload or not to reload?
Mario L de Lemos
BC Cancer Agency, Vancouver, BC, Canada
Karen Mason
BC Cancer Agency, Surrey, BC, Canada
Nadine Badry
BC Cancer Agency, Victoria, BC, Canada
Victoria Kyritsis
BC Cancer Agency, Vancouver, BC, Canada
Corresponding author: Mario L de Lemos, BC Cancer Agency, 600 West 10th Avenue, Vancouver, Canada, BC V5Z 4E6. Email: mdelemos@bccancer.bc.ca
Trastuzumab is an anti-HER monoclonal antibody given intravenously with a loading dose of 8 mg/kg or 4 mg/kg to be followed by maintenance dosing of 2 mg/kg weekly or 6 mg/kg every three weeks.1 Trastuzumab therapy for breast cancer is usually prolonged, with one year of adjuvant treatment2⇓⇓⇓–6 and potentially longer in the metastatic setting when it is usually given until progression.7 Therefore, delays in dosing are not uncommon, leading to concerns of subtherapeutic serum level and the need for a reloading dose. The timing of the reloading dose, however, depends on what serum level to …