Chronic morphine accelerates the progression of lipopolysaccharide-induced sepsis to septic shock.

Opiate addicts have been shown to have a high susceptibility to bacterial infection. We investigated how treatment with morphine alters lipopolysaccharide (LPS)-induced inflammatory responses in the rat. Chronic morphine alone elevated serum endotoxin levels. Animals treated with morphine and LPS (250 microg/kg) developed hypothermia, decreased mean arterial pressure (MAP), increased plasma thrombin anti-thrombin III (TAT) complex, and approximately 67% of animals exhibited progressive intramicrovascular coagulation. Morphine also enhanced LPS-induced leukocyte-endothelial adhesion (LEA), suppressed leukocyte flux, and corticosterone production, and elevated interleukin-1beta, tumor necrosis factor-alpha, and interleukin-6 serum levels. Our study presents both the molecular and cellular mechanisms underlying the potentiated LPS-induced inflammation and accelerated progression to septic shock seen with chronic morphine exposure.