To : Debra Re : Nubain(Nalbupine) and Stadol(butorphanol) Nalbupine and butorphanol are sometimes used by some anesthesiologists as an analgesic due to the fact that they do not suppress respiration like morphine. Nalbupine belongs to the family of opioid drugs which interact at the Kappa opiate receptor site, and only weakly at the Mu-1 receptor site. They are also called "Ceiling Opioids", in that they only produce minimal to modest respiratory depression with increasing doses. Morphine interacts primarily at the Mu-1 Mu-2 receptor sites and less so at the Kappa site. As such Nubain and the other Kappa analgesics can occasionally produce an unusual psychologic effect, so called a "psychotomimetic effect". This includes a floating sensation, and other hallucinogenic-like responses. This is rather rare, but it is a well known phenomenon of this family. Further, if this product is added on after the use of other opioids(morphine, demerol), it can displace the more potent original opioids and greatly increase the pain sensation in the patient. So we never mix kappa opiods with Mu opioids. As to whether it reduces or inhibits an infants' latch-on, we actually have no data, although I have heard this numerous times before. Infants appear awake, but don't seem to respond to normal stimuli. Is this the psychotomimetic effect? Who knows. Regards Tom Hale, Ph.D.