Table 4.
Urinary recovery during an interdosing interval of the enantiomers of methadone and EDDP from 10 methadone maintenance patients following chronic dosing of between 7.5mg and 130 mg rac-methadone once daily.
| Patient | Dose (mg kg−1) | (R)-methadone (%) | (S)-methadone (%) | % Dose recovered (R)-EDDP (%) | (S)-EDDP (%) | Total dose (%) |
|---|---|---|---|---|---|---|
| 9 | 1.91 | 8.6 | 5.3 | 9.8 | 14.2 | 37.9 |
| 10 | 0.33 | 6.1 | 3.7 | 10.7 | 16.6 | 37.1 |
| 11 | 0.82 | 10.6 | 7.8 | 8.2 | 11.5 | 38.1 |
| 12 | 0.30 | 10.7 | 6.5 | 8.9 | 12.9 | 39.0 |
| 13 | 0.86 | 13.3 | 6.7 | 10.8 | 15.2 | 46.0 |
| 14 | 0.77 | 12.0 | 7.2 | 3.8 | 5.3 | 28.3 |
| 15 | 0.12 | 5.8 | 3.3 | 1.9 | 2.9 | 13.9 |
| 16 | 1.41 | 7.3 | 4.3 | 11.0 | 16.6 | 39.2 |
| 17 | 0.93 | 13.7 | 10.1 | 6.5 | 8.6 | 38.9 |
| 18 | 0.68 | 8.0 | 4.6 | 10.6 | 17.4 | 40.6 |
| Mean | 0.88 | 9.6 | 6.01 | 8.2 | 12.12 | 35.9 |
| %CV | 57 | 30 | 35 | 39 | 41 | 25 |
1
Statistically significant difference (P value, mean difference; 95% CI) compared with (R)-methadone (P < 0.0001, −3.6; −4.6, −2.7)
2
statistically significant difference compared with (R)-EDDP (P = 0.0001, 3.9; 2.5, 5.3).