• Synthesis
  • Natural (known as opiates): morphine
  • Semisynthetic (derived from the morphine molecule): codeine, heroin, hydromorphone, oxycodone, oxymorphone
  • Synthetic: meperidine, alfentanil, fentanyl, sufentanil, remifentanil
• Potency (all may potentially produce serious side effects, including sedation, respiratory depression, hypotension, or bradycardia)
  • Weak: codeine, dextropropoxyphene, tramadol, hydrocodone
  • Medium: morphine, methadone, oxycodone, hydromorphone
  • Strong: fentanyl, sufentanil, alfentanil, remifentanil
• Effect at Opioid Receptor
  • Full agonists: morphine, methadone
  • Partial agonists: buprenorphine at MOR
  • Antagonists: naloxone, naltrexone
• Onset and Offset of Action
  • Rapid: remifentanil, alfentanil
  • Slow: morphine, buprenorphine

MOR = µ-opioid receptor.