Receptor binding affinity of traditional mu-opioid agonists (morphine and oxycodone) and NKTR-181 at mu-, delta-, and kappa-opioid receptors
| Ki (mean ± S.D.) | |||
|---|---|---|---|
| Mu | Delta | Kappa | |
| nM | nM | nM | |
| Morphine | 8.40 ± 1.3 | 4,300 ± 500 | 118 ± 25 |
| Oxycodone | 16.0 ± 1.1 | 7,680 ± 1,200 | 43,000 ± 1,800 |
| NKTR-181 | 237 ± 31 | 4,150 ± 870 | > 100,000 |