Cyclophosphamide and cortisol reduce the severity of morphine withdrawal.

Cyclophosphamide and cortisol, two nonspecific immunomodulators, significantly reduced the behavioral indices of naloxone-precipitated withdrawal in morphine dependent rats. Each immunomodulator reduced the morphine abstinence syndrome when administered either prior to or after chronic morphine treatment. Morphine exerts numerous effects on all levels of the central nervous system with tolerance, physical dependence, and a withdrawal syndrome being characteristics of this drug class. It is suggested that the degree of opiate dependence is directly correlated with the intensity of the behavioral withdrawal signs. Therefore, success in modifying the abstinence syndrome may lead to a better understanding of the dynamics of opiate dependence. The results reported herein coupled with similar findings for alpha-interferon and cyclosporine, suggest that opiate dependence may involve the immune system.