Tapentadol is an opioid pain medication. An opioid is sometimes called a narcotic. Tapentadol is used to treat moderate to severe pain. The extended-release form of tapentadol (Nucynta ER) is for around-the-clock treatment of pain that is not controlled by other medicines. Nucynta ER is not for use on an as-needed basis for pain. Amount 90 Pills, 120 Pills, 240 Pills, 360 Pills Dosage 50 mg, 100 mg