Interferon Inhibition by Narcotic Analgesics

Summary

Morphine, Dilaudid, and methadone were injected into mice in order to assess their effect on interferon production. It was found that all three narcotic analgesics significantly reduced the level of serum interferon induced by either poly I:C or endotoxin. The level of inhibition was directly related to drug dosage. The inhibitory effect of morphine can persist at least 9 days following a single injection. Interferon levels of certain tissues particularly spleen were also depressed in morphine–treated animals. This effect on the level of interferon does not appear to be mediated through an effect on body temperature nor can it be eliminated by the morphine antagonist naloxone. These drugs were also tested on cells in vitro using poly I:C as an inducer and do not appear to have a major effect on either the induction or the action of interferon in vitro.

The authors thank Dr. John J. Dallman, Department of Community Medicine, Medical College of Georgia for his assistance in the statistical treatment of these data.