ArticlesHydromorphone analgesia after intravenous bolus administrationCoda, Barbaraa,b,*; Tanaka, Akiraa; Jacobson, Robert C.a; Donaldson, Garya; Chapman, Richard C.a,bAuthor Information aDivision of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA, USA bDepartment of Anesthesiology, University of Washington, Seattle, WA, USA *Corresponding author. Pain and Pharmacology Research, Fred Hutchinson Cancer Research Center, 1124 Columbia Street, Room AB-122 Seattle, WA 98104, USA. Tel.: +1 206 6674580; fax: +1 206 6676115. Received September 1, 1995; revised version received December 3, 1996; accepted December 18, 1996. Pain: May 1997 - Volume 71 - Issue 1 - p 41-48 doi: 10.1016/S0304-3959(97)03336-8 Buy Metrics Abstract This study investigated the analgesic effects of three intravenous bolus doses of hydromorphone (10, 20, 40 μg/kg) on experimental pain measures in normal humans. Ten healthy male volunteers participated in four study sessions, one for each of the hydromorphone doses as well as a placebo (saline). They received the four treatments in counterbalanced order under double-blind conditions and with study days at least 1 week apart. During each session subjects underwent repeated electrical tooth pulp stimulation at intensities sufficient to elicit a rating of ‘strong pain’ before drug administration. Subjective pain reports (PRs) and dental evoked potential amplitude measures (EPs) served as analgesic effect indicators. We observed dose-dependent analgesia as measured by both PR (P=0.009) and EP (P=0.017). Area under the PR versus time curve as well as the EP versus time curve decreased in a log dose-dependent fashion. Although the peak effect was poorly defined, the onset of analgesia was rapid, within 5 min, and maximum analgesic effect was seen between 10 and 20 min after maximum plasma hydromorphone concentration. However, within sessions we found a poor correspondence between hydromorphone plasma concentration and effect. Compared to pain report data from other human studies done in our laboratory, hydromorphone has a shorter time to peak effect compared to morphine, and overall, hydromorphone hydrochloride is approximately five times as potent as morphine sulfate on a milligram basis. © Lippincott-Raven Publishers.