ACUTE COCAINE EFFECTS AN ABSOLUTE CEREBRAL BLOOD-FLOW

Cocaine use has been associated with vasoconstriction and stroke, and several studies have demonstrated that it decreases relative cerebral blood flow (rCBF) in humans. However, rCBF has not been quantitated. W e compared 40 mg IV cocaine hydrochloride to placebo effects on absolu te rCBF in four cocaine users using 99mTc-HMPAO SPECT with a modified microsphere model for CBF quantitation. Cocaine produced significant d ecreases in rCBF in all regions studied with a mean decrease of 30% in absolute whole brain blood flow (P = 0.002) which was 3-fold greater than relative blood flow changes.