The proposed study seeks to evaluate pain tolerance and analgesic response in drug abusers receiving opiate maintenance treatment, a population for which pain management is a frequent and clinically challenging issue. Although overlap between brain systems responsible for both pain and opiate dependence is increasingly appreciated, little is known about the experience of pain for persons chronically ingesting exogenous opiates. Thus we propose to describe pain tolerance in opiate-maintained individuals and evaluate their response to analgesic medications. A methadone-maintained (n = 54), a buprenorphine-maintained (n = 54) and a LAAM-maintained (n = 54) sample will be recruited, and their tolerance to a standardized cold-pressor test (CPT) will be evaluated upon admission to treatment and again once they have stabilized on opiate maintenance to learn if and how pain tolerance changes over the course of opiate maintenance treatment. The CPT analgesic response of these stabilized subjects will be evaluated by double blind administration of oral opiate (Dilaudid, 3 mg.), non-opiate (Toradol, 10 mg.), and placebo using a Latin square design, and compared to that noted in a sample of matched controls. Proposed analyses will provide information on 1) pain tolerance for treatment-seeking opiate addicts, 2) pain tolerance for three opiate- maintained samples, 3) analgesic agents which are effective for opiate- maintained persons, and 4) potential differences in pain response between persons maintained on methadone, buprenorphine and LAAM. It is anticipated that the findings from the proposed study will have important clinical implications for the assessment and treatment of pain in this population which is prone to painful morbidity.