This butorphanol drug class was introduced about 25-30 years back. That was the era of morphine, pethidine, so it did not gain much acceptance. But now re-introduced, has become a major “find”. It is a classical example of “resurrection”.
Butorphanol is a morphinan derivative with spectrum of activity almost like pentazocine, only that it is 20 times more potent than pentazocine.
It also means very less respiratory depression. It is of choice in acute and moderate to severe pain, usually postoperative pain.
The difference is it has minimal effect, thus the psychomimetic effects are less. Due to even more antagonism butorphanol drug class has practically minimal addictive potential.