Tramadol, a powerful pain reliever, is used to treat moderate to severe pain that cannot be relieved by other pain relievers. Tramadol, a synthetic opioid, works on the brain and spine (central nervous system) to reduce pain perception. Tramadol is offered in an extended-release version for long-term pain relief. Tramadol in this form should not be used on an as-needed basis to alleviate pain. Tramadol inhibits the absorption of two neurotransmitters, norepinephrine and serotonin, in addition to acting on the opioid pain receptor, which may improve its pain-relieving effects; however, the exact mechanism is uncertain.