Prescription opioid analgesics like Tramadol are used to treat moderate to severe pain. It functions by influencing neurotransmitters like serotonin and norepinephrine and changing how pain is perceived in the brain. Tramadol functions as both a serotonin-norepinephrine reuptake inhibitor (SNRI) and a mild opioid receptor agonist, in contrast to conventional opioids.