Hirsch and Poller's1 article in the February 14, 1994, issue of the Archives contains a protocol of subcutaneous phytonadione to reverse warfarin overanticoagulation. They referenced an article that appeared in Chest in 1992.2 The article contained an intravenous phytonadione protocol. We would like to know the rationale for the change in the route of administration. Are both routes equally effective?