Table 1.
Examples of preclinical and clinical opioid drugs.
| Ligand | Selectivity | Activity | |
|---|---|---|---|
| Morphine | MOPr >> KOPr | Agonist | Analgesia Respiratory depression |
| Heroin | MOPr >> KOPr | Agonist | Fast penetration in the brain Acts through its mainly active metabolite, morphine |
| Buprenorphine | MOPr DOPr KOPr | Partial agonist AntagonistAntagonist | Reduces withdrawal Low risk of respiratory depression |
| Methadone | MOPr | Agonist | Reduces withdrawal, risk of respiratory depression |
| TRV130 | MOPr | Agonist (biased toward G protein) | |
| PMZ21 | MOPr > KOPr > DOPr | Biased agonist Antagonist Weak agonist | Analgesia |
| Cebranopadol | MOPr, KOPr, NOPr > DOPr | Agonist (partial at KOPr) | Reduced respiratory depression |
| AT-121 | MOPr, NOPr > DOPr KOPr | Partial agonist Partial agonist | |
| Naloxone | MOPr, DOPr, KOPr | Antagonist | Blocks euphoric effects Reverses respiratory depression |
| Naltrexone | MOPr, KOPr > KOPr | Antagonist | |
| PL37, PL265 | MOPr, DOPr (via enkephalins) | Inhibit enkephalins degradation | Analgesia Lack opioid-associated side effects |