Use of compounds (I), which exhibit an affinity for the mu -opioid-receptor of at least 100 nM (K i value for human) and an affinity for opioid receptor-like (ORL)-1-receptor, is claimed, where the ratio of the affinities ORL1/mu defined as 1/[K i(ORL1)/K i(mu )] is 1:10 to 30:1, for the production of a medicament and to treat: diabetic neuropathy； narcosis or analgesia during narcosis； pain in patients over 60 years and in patients with increased addictive potential and postoperative pain. An independent claim is included for use of a mu -agonist (II), which is selective as an ORL1/mu defined as 1/[K i(ORL1)/K i(mu )] 1:10, and a ORL1-agonist, which is selective as ORL1/mu defined as 1/[K i(ORL1)/K i(mu )] in a ratio of 30:1 in a mixture, which exhibits the characteristics of the compounds, for the manufacture of medicaments to treat pain. ACTIVITY : Neuroprotective； Analgesic. MECHANISM OF ACTION : Opioid receptor-like-1/mu -agonist.
