Tramadol/Ultram is a synthetic opioid. It is not an SSRI. It is metabolized using some of the same pathways and can increase serotonin in the brain but the assertion that “the LARGEST portion of the tablet is an SSRI” is untrue. “Tramadol is metabolized through CYP2D6 enzymes and all SSRIs are inhibitors of these enzymes. Inhibitors of CYP2D6 can increase the concentration of tramadol in the blood and thus increase its effects on serotonin in the brain, contributing to the development of serotonin syndrome. CYP2D6 poor metabolizers are at a greater risk of serotonin syndrome and an inadequate analgesic effect.