Nucynta (tapentadol) is an opioid pain medication and is used to treat moderate to severe pain. Nucynta is for around-the-clock treatment of pain that is not controlled by other medicines. It is not for use on an as-needed basis for pain.You should not use Nucynta if you have severe breathing problems, or a bowel obstruction called paralytic ileus. Do not use Nucynta if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, and tranylcypromine. Tapentadol can slow or stop your breathing, especially when you start using this medicine or whenever your dose is changed. Never take this medicine in larger amounts, or for longer than prescribed. Do not crush, break, or open an extended-release tablet. Swallow it whole to avoid exposure to a potentially fatal dose.