Bulaev V M, Zakusov V V, Knoll Zh, Chichenkov O N
Biull Eksp Biol Med. 1978 Jun;85(6):685-8.
As revealed, in acute experiments on rabbits, cats, and rats, a new morphine-like synthetic analgesic drug azidomorphine exceeded 20--100-fold the morphine ability to inhibit synaptic transmission in the thalamic structures, cerebral cortex, and the spinal cord during the nociceptive stimulation, and also by its analgesic activity.