Examples of such compounds include nalorphine and levallorphan.
Naltrexone should not be confused with naloxone nor nalorphine, which are used in emergency cases of opioid overdose.
The opioid antagonist activity of Nalbuphine is one-fourth as potent as nalorphine and 10 times that of pentazocine.
Similarly to nalorphine, nalodeine has also been found to act as an agonist of the ?-opioid receptor.
The analgetic potency is about the same as of pethidine ( meperidine ), the antagonistic effect is 1 / 50 of nalorphine.
Diacetylnalorphine may behave as a prodrug to nalorphine, similarly to the cases of heroin ( diacetylmorphine ) to morphine and diacetyldihydromorphine to dihydromorphine.
Berry forces her to confess in the hospital by threatening her with what she believes is an excruciatingly painful dose of Nalorphine ( but is actually water ).
Nalorphine was the second opioid antagonist to be introduced, preceded by nalodeine ( N-allylnorcodeine ) in 1915 and followed by naloxone in 1960 and naltrexone in 1963.
The compound has relatively little opioid activity in its own right, but is a useful intermediate which can be used to produce both opioid antagonists such as nalorphine, and also potent opioid agonists such as N-phenethylnormorphine.
Diprenorphine is the strongest opioid antagonist that is commercially available ( some 100 times more potent as an antagonist than nalorphine ), and is used for reversing the effects of very strong opioids for which the binding affinity is so high that naloxone does not effectively or reliably reverse the narcotic effects.