Intriguing article about tapentadol, a mu-opioid agonist made Grunenthal, the same company who brought tramadol (and thalidomide!) to the world. Similarly to tramadol, tapentadol has been marketed as a safer alternative to opioids (although this claim is limited to marketing materials from Grunenthal), and explanations for this rationale are few. However erroneous, this conception has driven prescribing popularity of the drug, which is now the most commonly prescribed opioid in Australia. Unsurprisingly, it has caused problems typical of other opioids.
Like tramadol, it has a "dirtier" mechanism: along with mu-opioid agonism, it also will inhibit norepinephrine reuptake, leading to a more activated (ie awake) patient. This is likely the germ of what led to safety claims, but also like tramadol, this leads to a seizure predisposition in overdose.
Unlike tramadol, therapeutic (ie normal) dosing of tapentadol has never been documented to lead to seizure. However, literature regarding tapentadol is still relatively slim. If you ever see a patient on this who seizes, let me know and we'll write it up--always a good time to level the playing field overpopulated by drug company claims.