Prescription opioid misuse: characteristics of earliest and most recent memory of hydromorphone use.

Objectives: Prescription opioid use is highly prevalent and a major physician concern. However, little is known about how individuals initiate into use of these medications or how they use them later in life. Hydromorphone is a medication of particular interest given its subjective similarities to heroin and tendency to be misused by illicit opioid users. The purpose of this study was to evaluate the characteristics of initial, and more recent, hydromorphone use occasions as remembered by a population of individuals in treatment for their opioid use. Methods: Seventy-eight clients enrolled in low-threshold methadone maintenance treatment were interviewed regarding their earliest and most recent uses of hydromorphone. Results: Hydromorphone was first used after trying many different substances (eg, tobacco, alcohol, hallucinogens, powder cocaine). Two-thirds of the sample reported initially using hydromorphone without a prescription. Participants who initially used hydromorphone without a prescription reported using for different reasons (ie, to get high, curiosity vs manage pain), via different routes of administration (ie, injection vs orally), and were more likely to couse other substances, than those whose earliest hydromorphone use was prescribed. However, these 2 subgroups did not differ greatly during their most recent use occasion (ie, the majority reported using to avoid withdrawal, via injection; almost 50% reported co-use with other substances). Conclusions: There was considerable variability in characteristics of hydromorphone use initiation among individuals enrolled in lowthreshold methadone maintenance treatment. However, later use of hydromorphone was remarkably consistent across individuals and shares many characteristics previously documented for heroin use.