Blood Oxygenation and Heart Rate Changes after Diamorphine Intravenous Injection during Opioid Agonist Treatment for Outpatients With Heroin Dependence

Abstract

Objectives More than 60 million people use opioids each year, and many countries have declared an opioid overdose crisis. Heroin, one of the most commonly used opioids, has depressant effects on autonomic functioning; however, few studies have been able to examine the effects of heroin or its pharmaceutically prepared equivalent, diamorphine, in human clinical populations. The present study examined heart rate and oxygen saturation in the minutes immediately after acute diamorphine administration in outpatients with heroin dependence. Methods The sample was a subset of participants (N = 36) in the German Project of Heroin Assisted Treatment of Opiate Dependent Patients Trial in Bonn, Germany. Patients were given 3 daily doses of intravenous diamorphine. Doses were determined on an individual basis by study physicians. Pulse oximetry was recorded at baseline and at 30-second intervals from 0 to 450 seconds after diamorphine administration. Results Heart rate was significantly higher than baseline at 30 seconds after diamorphine administration and significantly lower than baseline at 270 seconds onward. Oxygen saturation was significantly lower than baseline at 60 seconds onward. Conclusions Results are consistent with other studies in which depressant effects of opioids were observed. Our findings suggest that even therapeutic doses of diamorphine may have rapid and significant—predominantly depressant—effects on oxygenation and heart rate in populations that frequently use opioids. Monitoring of potential adverse opioid effects would be beneficial even in populations presumed to have developed physiological tolerance.