[Observation of acenocoumarol-induced granulocytosis].

A male patient had been treated with acenocoumarol for 9 years. Raised white cell count returned to normal, when acenocoumarol was substituted by heparin, but rose again after reexposure. An analysis of variance showed that this effect is mediated by neutrophils only. The rise is quick and may therefore be caused by a redistribution of white cells rather than by increased cell production.