An immediate-release oral tablet, tapentadol HCl has received FDA approval to treat moderate to severe acute pain. It's available in doses of 50, 75, and 100 mg.

A novel, centrally acting synthetic analgesic, tapentadol has both opioid and nonopioid properties. By activating mu-opioid receptors in the central nervous system, it modifies pain perception. In addition, it inhibits norepinephrine reuptake, which may have an analgesic effect by increasing norepinephrine in the brain.

Tapentadol was tested in patients undergoing bunionectomy, a painful foot surgery, and in those with degenerative, end-stage joint disease of the hip or knee. Its effectiveness was comparable to that of "strong opioids," according to the manufacturer, Ortho-McNeil. The most common adverse reactions were nausea, dizziness, vomiting, and somnolence.