C M Bernards1, B F Cullen, K M Powers. 1. Department of Anesthesiology, University of Washington, Seattle 98195-6540, USA. chrisb@u.washington.edu
Abstract
BACKGROUND: The purpose of this study was to determine how chronic cocaine exposure affects the hemodynamic response to epinephrine, dopamine, phenylephrine, and ephedrine in awake sheep. METHODS: The hemodynamic response to dopamine (10 microg/kg), phenylephrine (1.5 microg/kg), and ephedrine (0.15 mg/kg) boluses was determined at baseline before low-dosage cocaine exposure and again after 15 and 18 days of cocaine exposure. The hemodynamic response to epinephrine (0.15 microg/kg), phenylephrine (1.5 microg/kg), and ephedrine (0.15 mg/kg) was determined at baseline before high-dosage cocaine exposure and again after 15 and 18 days of cocaine exposure. RESULTS: Chronic cocaine exposure abolished the mean arterial pressure and heart rate responses to dopamine but did not alter the responses to epinephrine, phenylephrine, or ephedrine. CONCLUSION: In awake sheep, chronic cocaine exposure markedly impairs the hemodynamic response to dopamine but not to epinephrine, phenylephrine, or ephedrine.
BACKGROUND: The purpose of this study was to determine how chronic cocaine exposure affects the hemodynamic response to epinephrine, dopamine, phenylephrine, and ephedrine in awake sheep. METHODS: The hemodynamic response to dopamine (10 microg/kg), phenylephrine (1.5 microg/kg), and ephedrine (0.15 mg/kg) boluses was determined at baseline before low-dosage cocaine exposure and again after 15 and 18 days of cocaine exposure. The hemodynamic response to epinephrine (0.15 microg/kg), phenylephrine (1.5 microg/kg), and ephedrine (0.15 mg/kg) was determined at baseline before high-dosage cocaine exposure and again after 15 and 18 days of cocaine exposure. RESULTS: Chronic cocaine exposure abolished the mean arterial pressure and heart rate responses to dopamine but did not alter the responses to epinephrine, phenylephrine, or ephedrine. CONCLUSION: In awake sheep, chronic cocaine exposure markedly impairs the hemodynamic response to dopamine but not to epinephrine, phenylephrine, or ephedrine.