About naloxonea ?-opioid receptor competitive antagonist, narcotic antagonist.mechanism of action of naloxonenaloxone is a pure semisynthetic opiate antagonist. it acts as a competitive antagonist at mu, kappa and delta opiate receptors in the cns. it reversibly and completely blocks all the opioid receptors (mu, kappa and delta).indications for naloxone1.opioid poisoning 2.opioid-induced respiratory depression