Table 2.
The Pharmacokinetic Parameters of Esketamine, R-Ketamine, S-Norketamine, and R-Norketamine in the Esketamine Group and the Ketamine Group
| Parameters | Esketamine Group (N=16) | Racemic Ketamine Group (N=16) | P | |
|---|---|---|---|---|
| Esketamine | Tmax (min) | 1.17 (0.28–1.25) | 1.15 (0.23–1.28) | 0.225a |
| Cmax (ng/mL) | 2277.60±2697.60 | 1976.80±1518.70 | 0.861 b | |
| AUC0-t (h·ng/mL) | 441.90±85.50 | 435.70 ±89.60 | 0.828 b | |
| AUC0-∞ (h·ng/mL) | 475.20±86.50 | 469.00±99.50 | 0.803 b | |
| CL (mL/min·kg) | 18.10±3.20 | 18.40±3.40 | 0.804 b | |
| t1/2 (min) | 287.50±110.20 | 283.20±117.80 | 0.864 b | |
| V (mL/kg) | 7390.80±2703.70 | 7285.90±2541.90 | 0.964 b | |
| R-ketamine | Tmax (min) | – | 1.15 (0.23–1.28) | 1.000c |
| Cmax (ng/mL) | – | 2064.40±1573.90 | <0.001** d | |
| AUC0-t (h·ng/mL) | – | 510.50±113.10 | <0.001** d | |
| AUC0-∞ (h·ng/mL) | – | 547.30±121.60 | <0.001** d | |
| CL (mL/min·kg) | – | 15.80±3.10 | <0.001** d | |
| t1/2 (min) | – | 343.40±112.70 | 0.003** d | |
| V (mL/kg) | – | 7614.80±2150.00 | 0.265 b | |
| S-norketamine | Tmax (min) | 20.17 (10.15–20.22) | 10.19 (10.12–20.20) | 0.065 a |
| Cmax (ng/mL) | 129.70±28.9 | 136.00±29.10 | 0.544 b | |
| AUC0-t (h·ng/mL) | 764.60±222.00 | 723.80±1860.80 | 0.662 b | |
| AUC0-∞ (h·ng/mL) | 871.00±262.30 | 782.80± 158.20 | 0.622 b | |
| CL (mL/min·kg) | 10.10±3.30 | 10.60±3.00 | 0.624 b | |
| t1/2 (min) | 519.00±117.00 | 475.10±65.90 | 0.826 b | |
| V (mL/kg) | 7593.70±2399.40 | 7806.50±2173.40 | 0.736 b | |
| R-norketamine | Tmaxa (min) | – | 20.13(10.15–30.0) | – |
| Cmax (ng/mL) | – | 149.40±32.60 | – | |
| AUC0-t (h·ng/mL) | – | 822.40±216.10 | – | |
| AUC0-∞ (h·ng/mL) | – | 882.40±217.00 | – | |
| CL (mL/min·kg) | – | 9.50±2.80 | – | |
| t1/2 (min) | – | 453.80±64.40 | – | |
| V (mL/kg) | – | 6640.90±1794.70 | – | |
Notes: Values are presented as mean ± SD, except Tmax, which is the median (range). aStatistics by Wilcoxon rank-sum test. bStatistics by Student’s t-test. cStatistics by Wilcoxon signed-rank-sum test. dStatistics by paired t-test. **P<0.01.
Abbreviations: Cmax, maximum plasma concentration; Tmax, time to reach Cmax; AUC0-∞, area under the plasma concentration–time curve from time zero to infinity; AUC0-t, area under the plasma concentration–time curve from zero until last measurable concentration; t1/2, elimination half-life; SD, standard deviation.