The influence of droperidol on blood viscosity in man.

An increase in blood viscosity and haematocrit, and a decrease in plasma volume, have been shown to follow stimulation of the sympathetic nervous system, as associated with, for example, severe exercise, emotional excitement or the administration of some sympathomimetic amines (Kaltreider and Meneely, 1940; Kaltreider, Meneely and Allen, 1942; Conn, 1966). It is to be expected that a depression of sympathetic nervous activity will produce opposite effects. Guanethidine and phenoxybenzamine, which have an adrenergic blocking action, have in fact been reported as producing an increase in plasma volume (Weil and Chissey, 1968). No studies have been published as yet on the effect of this latter group of agents on blood viscosity and haematocrit. Droperidol, a neuroleptic drug, is known to reduce sympathetic activity by means of sedation and a specific adrenergic blocking effect (Foldes et al., 1966; Yelnosky, Katz and Dietrich, 1963; Deligne, 1968). The purpose of this study was to determine whether the injection of droperidol in man influences blood viscosity and haematocrit values.