Tapentadol ER 100mg: What It Treats, How It Works, and What to Watch For If your doctor has mentioned tapentadol extended-release (often sold under brand names like Tapal ER, Nucynta ER, or Palexia SR) for chronic pain, you probably have two questions before anything else: does this actually work for pain like mine, and how risky is it? Those are the right questions to ask about any long-acting...