Not to be administered as IV push or bolus. Evaluate cardiac function prior & during treatment, especially w/ prior anthracycline & cyclophosphamide exposure. Cardiac assessment should be repeated 3 mthly during treatment & 6 mthly after discontinuation until 24 mth from last administration. Discontinue treatment for cardiomyopathy, anaphylaxis, angioedema, interstitial pneumonitis or acute resp distress syndrome, severe or life-threatening infusion-related reactions & in patients w/ continued decrease in LVEF but remain asymptomatic. Perform HER2 testing prior to initiation of therapy. To reduce risk of infusion-related reactions, premedication may be used. Discontinue infusion or slow the rate of infusion if infusion reaction occurs. Increased risk of interstitial lung disease w/ prior or concomitant anticancer eg, gemcitabine, taxanes, vinorelbine & radiation therapy. Patients experiencing dyspnoea at rest due to complications of advanced malignancy/comorbidities are at risk of fatal infusion reactions & should not be treated w/ trastuzumab. Use w/ caution in pneumonitis especially w/ concomitant therapy w/ taxanes. Patients experiencing infusion-related symptoms should not drive & use machines. Avoid pregnancy & lactation. Associated toxicity w/ benzyl alcohol in neonates & childn up to 3 yr.