High-dose metoclopramide and dexamethasone as an antiemetic in outpatients receiving chemotherapy for breast cancer. Second study.

Forty-six outpatients with breast cancer who had experienced severe emesis as a result of chemotherapy were evaluated for the antiemetic efficacy of high-dose metoclopramide (HD-MCP) and dexamethasone (DXM). Chemotherapy consisted of: cyclophosphamide 600, methotrexate 40 and 5-fluorouracil 600 mg/m2 (CMF) given intravenously every 3 weeks. The dosage of antiemetic drugs was MCP 2 mg/kg and DXM 0.2 mg/kg given by slow intravenous drip 0.5 h before the administration of chemotherapy. 138 courses of combined chemotherapy--HD-MCP and DXM--were administered, with a mean of 3 courses and a range of 1-10 courses per patient. Complete protection--no nausea and no vomiting--was achieved in 17.7% of the courses. Partial protection--no vomiting with mild nausea or 1-3 episodes of vomiting--in 45.3% of the courses. The total antiemetic efficacy was 63%. The most common side effects were: drowsiness, dry mouth, restlessness and diarrhea. Sixteen patients (35%) refused to continue the antiemetic regimen because of the side effects. HD-MCP and DXM have antiemetic efficacy, but because of these side effects, further studies are required to determine the optimal dose of each of these drugs.