Tramadol is a prescription medication used to relieve moderate to moderately severe pain. It is classified as an opioid analgesic, although it also has some properties of antidepressants, affecting neurotransmitters in the brain such as serotonin and norepinephrine. Tramadol works by binding to opioid receptors in the brain and spinal cord, which alters the perception of pain. It also inhibits the reuptake of serotonin and norepinephrine, which may contribute to its analgesic effects.