Nalodeine
Nalodeine, also known more commonly as N-allylnorcodeine, is an opioid antagonist that was never marketed but is notable as the first opioid antagonist to be discovered. It was first reported in 1915, and this was followed by the clinical introduction of nalorphine in 1954, naloxone in 1960, and naltrexone in 1963. Nalmefene, another structurally related opioid antagonist derivative, was also subsequently introduced, in 1996. In animals, nalodeine both reverses morphine- and heroin-induced respiratory depression and acts as a respiratory stimulant in its own right. Similarly to nalorphine, nalodeine has also been found to act as an agonist of the κ-opioid receptor.
