Table 1.
Primary pharmacokinetic parameters for morphine, M3G and M6G.
| Parameter | Morphine + OND* | Morphine Morphine + NS* | Ratio† | Morphine +.OND* | M3G Morphine + NS* | Ratio† | Morphine + OND | M6G Morphine + NS* | Ratio† |
|---|---|---|---|---|---|---|---|---|---|
| AUCinf | 96.0 | 103.4 | 0.93 | 1326.0 | 1358.6 | 0.98 | 128.7 | 125.0 | 1.03 |
| (ng ml−1 h) | (85.9–107.2) | (92.2,116.0) | (0.85,1.01) | (1193.8,1472.9) | (1202.1,1535.3) | (0.93,1.02) | (109.3,151.6) | (103.3,151.4) | (0.95,1.11) |
| CL | 88.6 | 82.2 | 1.08 | NA | NA | NA | NA | NA | NA |
| (l h−1) | (79.1–99.2) | (73.1,92.4) | (0.99,1.17) | ||||||
| t½ (h) | 2.6 | 2.5 | 1.05 | 15.2 | 15.7 | 0.97 | 2.5 | 2.2 | 1.16 |
| (2.4–2.9) | (2.2,2.9) | (0.97,1.15) | (12.9,17.9) | (13.3,18.6) | (0.83,1.13) | (2.2,2.9) | (1.9,2.5) | (1.04,1.28) | |
| Cmax | 204.9 | 193.3 | 1.06 | 167.9 | 174.1 | 0.96 | 29.0 | 30.1 | 0.97 |
| (ng ml−1) | (150.2–279.5) | (145.5,256.7) | (0.89,1.26) | (147.2,191.4) | (151.2,200.3) | (0.90,1.03) | (25.4,33.1) | (26.3,34.4) | (0.90,1.03) |
| tmax (h) | 0.08 | 0.08 | NA | 0.42 | 0.50 | 0.00 | 1.00 | 0.75 | 0.08 |
| (0.08–0.08) | (0.08,0.08) | (0.25,1.00) | (0.33,0.75) | (−0.11,0.13) | (0.75,1.05) | (0.33,1.50) | (−0.13,0.28) |
*
Geometric means (95% confidence intervals); median value (range) for tmax.
†
Ratio of the least squares means for the log transformed parameters (90% confidence intervals); median difference (90% confidence intervals) for tmax. OND, ondansetron; NS, normal saline solution; AUCinf, area under the concentration vs time curve extrapolated to infinity; CL, total systemic clearance of morphine; t½, apparent half-life based on the terminal elimination rate constant λz; Cmax, maximum observed plasma concentration; tmax, first time to Cmax. Note: the molecular weights for morphine, M3G and M6G are 285.34, 478.5, and 478.5, respectively.