Opium alkaloids

Phenanthrenes naturally occurring in opium:

• Codeine
• Morphine
• Thebaine
• Oripavine

Preparations of mixed opium alkaloids, including papaveretum, are still occasionally used.

Semisynthetic derivatives

• Diacetylmorphine (heroin)
• Dihydrocodeine
• Hydrocodone
• Hydromorphone
• Nicomorphine
• Oxycodone
• Oxymorphone

Synthetic opioids

Anilidopiperidines

• Fentanyl
• Alphamethylfentanyl
• Alfentanil
• Sufentanil
• Remifentanil
• Carfentanyl
• Ohmefentanyl

Phenylpiperidines

• Pethidine (meperidine)
• Ketobemidone
• MPPP
• Allylprodine
• Prodine
• PEPAP

Diphenylpropylamine derivatives

• Propoxyphene
• Dextropropoxyphene
• Dextromoramide
• Bezitramide
• Piritramide
• Methadone
• Dipipanone
• Levomethadyl Acetate (LAAM)
• Loperamide (used for diarrhoea, does not cross the blood-brain barrier)
• Diphenoxylate (used for diarrhoea, does not appreciably cross the blood-brain barrier)

Benzomorphan derivatives

• Dezocine
• Pentazocine
• Phenazocine

Oripavine derivatives

• Buprenorphine
• Dihydroetorphine
• Etorphine

Morphinan derivatives

• Butorphanol
• Nalbuphine
• Levorphanol
• Levomethorphan

Others

• Lefetamine
• Meptazinol
• Tilidine
• Tramadol
• Tapentadol

Opioid antagonists

• Nalmefene
• Naloxone
• Naltrexone