Disclosed are compounds of the formulae (II) and (III), and pharmaceutically acceptable salts thereof: (II) (III) wherein * represents the relative cis- or trans- conformations in formulae (II) and (III) respectively and R1, R2, each R3, each R4, n and m are as defined herein. The compounds are modulators of norepinephrine transporters (NET),
dopamine transporters (DAT),
serotonin transporters (SERT), sigma-1
receptor (σ1R), muscarinic M1 receptors and / or muscarinic M2 receptors and are expected to be useful in the treatment of pain, neuropsychiatric or neurodegenerative diseases, sleep disorders, as a
sedative or as an anaesthetic.