The primary endpoints of this study are measures of ACTH, cortisol, LH, and testosterone secretion, whereas secondary endpoints are neurobehavioral indices such as pain symptomatology on a 0-10 (Likert) scale, the Oswestry Disability Index, Multidimensional Pain Inventory, and the Beck Depression Inventory. It is anticipated that the results of the second phase of this study will provide novel information regarding the effects of treatment with opioids on selected neuroendocrine functions in men.