IN-VITRO EVALUATION OF FENTANYL AND MEPERIDINE FOR IMMUNOMODULATORY ACTIVITY

Exposure to drugs, either ethical pharmaceuticals or illicit street dr ugs, often results; in medical complications, including alterations in the immune system. Among the drugs associated with immunomodulatory p otential are the analgesics fentanyl and meperidine. The purpose of th is study was to determine the potential of these drugs to alter immuno logical parameters subsequent to in vitro exposure at a range of conce ntrations. This potential immunotoxicity was assessed using a series o f in vitro assays measuring B-lymphocyte proliferation, cytokine produ ction by T-helper lymphocytes, T-lymphocyte cytolytic function, natura l killer (NK) cell function, and macrophage function. Exposure to thes e analgesics was associated with a differential suppression of interle ukin-4 production by T-cells, as well as a more generalized suppressio n of cytokine production by macrophages. In addition, T-cell cytolytic activity was suppressed at high drug concentrations. B-cell prolifera tion and NK cell activity were also inhibited, but to a lesser degree than noted with T-cell function. Addition of naltrexone to the culture s did not reverse these alterations in immune function, suggesting tha t these changes are not mediated via opioid receptors.