Pharmacokinetics and bioavailability of hydromorphone following intravenous and oral administration to human subjects.

In a relatively small pilot study, the half-life of elimination of hydromorphone in six subjects was 2.64 +/- 0.88 hours and the drug had a high volume of distribution, 1.22 l./kg. In addition, the drug was rapidly but incompletely absorbed after oral administration. An equation to predict the plasma concentration of hydromorphone on oral administration was developed from the data of these six subjects.