Subacute vincristine toxicity following five consecutive daily doses.

Vincristine (VCR) is commonly included in combinational chemotherapy regimens because of its synergy with a variety of other active agents, as well as its sparing of the hematopoietic system. While acute toxicity is not infrequently reported, a recent experience in an adult who received five consecutive daily doses of VCR (1.0 mg/m2) in conjunction with two other drugs led to a sequence of life-threatening toxicities which were not obviously ameliorated by folinic acid rescue as has been recently advocated. The increasing administration of protocol chemotherapy by practitioners in the community, who may not be especially familiar with the particular agents in a given regimen, suggests such errors may become more common.