Buprenorphine is classified as:-

Buprenorphine is paial agonist at mu receptor with kappa and delta antagonistic propey. It is useful as an analgesic and as an alternative to methadone for the management of opioid withdrawal. Nalbuphine, pentazocine and dezocine are k agonists and m receptor antagonists. These drugs can produce psychomimetic effects with hallucinations, nightmares and anxiety. Butorphanol is a predominant k agonist that produces equivalent analgesia but more sedation than morphine.