Oxycodone is more potent, roughly 1 to 8 times stronger than tramadol, used for severe pain with a high risk of addiction. Tramadol is less potent for moderate to severe pain. Tramadol acts as an opioid, but also increases serotonin. It can cause seizures. Oxycodone is a direct, strong opioid agonist. Oxycodone uses foe severe pain, acute pain, or post-surgical pain, etc. Oxycodone carries a higher risk of fetal respiratory depression.