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

Aims. To determine the relationship between severity of opiate withdrawal a nd prior heroin dose and route of administration (smoking versus intravenou s injection). Design. Retrospective analysis of withdrawal data and assessm ent of associations with baseline variables including heroin dose, route of administration, duration of use, concomitant use of cocaine, severity of o piate dependence, previous treatment, sex or age. Setting. Psychiatric inpa tient unit specialized in withdrawal treatments. Participants. Twenty-two o piate addicts injecting or smoking heroin who were abruptly withdrawn after admission.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. F indings. Severity and duration of withdrawal symptoms were greater in injec tors compared to smokers (with comparable doses) and also in patients with higher heroin dose. Heroin dose and route of administration were related si gnificantly to total and maximum withdrawal scores and together accounted f or about 50% of variance. Similar levels of total withdrawal distress were associated with approximately five times higher heroin consumption in chase rs than in injectors. Conclusions. The impact of heroin dose and route of a dministration on withdrawal severity is marked. The influence of the route of administration on withdrawal severity might be due to differences in bio availability.