Morphine is considered the gold standard for pain relief, but for some, morphine can actually increase pain. The good news is, a team of researchers from several different hospitals is closer than ever before to finding a solution to this problem. They discovered a molecular pathway through which morphine can increase pain. There are specialized cells in the spinal cord called microglia with receptors that, when acted upon by morphine, trigger events that increase the activity of pain-transmitting nerve cells. The molecule acted upon is a protein called KCC2 which regulates the control of sensory signals to the brain. In theory, if they can restore normal KCC2 activity, they can stop the pain from morphine.
Read the full article here: How Morphine Can Increase Pain