The influence of heroin dose and route of administration on the severity of the opiate withdrawal syndrome

Abstract

Aims: To determine the relationship between severity of opiate withdrawal and prior heroin dose and route of administration (smoking versus intravenous injection). Design. Retrospective analysis of withdrawal data and assessment of associations with baseline variables including heroin dose, route of administration, duration of use, concomitant use of cocaine, severity of opiate dependence, previous treatment, sex or age. Setting. Psychiatric inpatient unit specialized in withdrawal treatments. Participants. Twenty-one opiate addicts injecting or smoking heroin who were abruptly withdrawn after admission. Measurements. Daily assessment of withdrawal severity with the Opiate Withdrawal Scale (OWS) during the first week after drug cessation. Findings. Severity and duration of withdrawal symptoms were greater in injectors compared to smokers (with comparable doses) and also in patients with higher heroin dose. Heroin dose and route of administration were related significantly to total and maximum withdrawal scores and together accounted for about 50% of variance. Similar levels of total withdrawal distress were associated with approximately five times higher heroin consumption in chasers than in injectors. Conclusions. The impact of heroin dose and route of administration on withdrawal severity is marked. The influence of the route of administration on withdrawal severity might be due to differences in bioavailability.