Get 10% Discount Apply Coupon Code "USA10" A synthetic opioid painkiller called tramadol is used to treat moderate to severe pain. In addition to binding to opioid receptors in the brain and spinal cord, it also slightly inhibits the reuptake of norepinephrine and serotonin. Tramadol is frequently given to treat a variety of pain problems, including neuropathic pain, osteoarthritis, and postoperative pain.