TNF and brain injury: Recent reports show an increase in interleukin (IL)-1B, IL-6, and tumor necrosis factor (TNF)-α after morphine and/or M3G administration in rodents and clinically in the contexts of acute inflammatory brain injury.9, 10, 11, 12, 13, 14 Under normal circumstances, morphine crosses the BBB, but M3G is impermeable owing to its more hydrophilic nature.15