TABLE 2.
Geometric mean pharmacokinetic parameters (%CV) of naloxone, naltrexone, and 6β-naltrexol
| Variablea (U) | Naloxone |
Naltrexone |
6β-Naltrexol |
|||
|---|---|---|---|---|---|---|
| Alone (Treatment B) | Plus Naltrexone (Treatment C) | Alone (Treatment A) | Plus Naloxone (Treatment C) | Alone (Treatment A) | Plus Naloxone (Treatment C) | |
| N | 11 | 11 | 12 | 11 | 12 | 11 |
| Cmax (ng/ml) | 4.30 (47.5) | 3.60 (36.5) | 4.55 (80.0) | 1.71 (35.1) | 2.09 (32.5) | 2.09 (26.2) |
| Tmax (h) | 0.50 (0.25–0.75) | 0.50 (0.25–0.75) | 0.33 (0.17–1.0) | 0.75 (0.25–2.0) | 2.00 (0.75–4.0) | 2.00 (0.75–3.0) |
| AUC0–inf (ng·h/ml) | 8.13 (38.2) | 7.00 (32.5) | 9.61 (39.1) | 5.88 (25.2)b | 30.8 (32.7) | 28.3 (28.4) |
| λz (h−1) | 0.380 (32.1) | 0.355 (43.9) | 0.319 (18.2) | 0.322 (10.3)b | 0.0433 (31.6) | 0.0430 (24.5) |
| t1/2 (h) | 1.83 (32.1) | 1.95 (45.7) | 2.17 (18.2) | 2.15 (10.3)b | 16.0 (31.6) | 16.1 (24.5) |
| CL/F (l/min) | 6.71 (38.2) | 7.79 (43.9) | 3.12 (39.1) | 5.10 (25.2)b | NC | NC |
AUC0–inf, area under the plasma concentration-time curve from time zero to infinity; CL/F, apparent clearance; λz, terminal phase rate constant; NC, not calculated; t1/2, terminal phase half-life; Tmax, time to reach Cmax; Treatment A, 2 mg naltrexone, intranasally; Treatment B, 4 mg naloxone, intranasally; Treatment C, 2 mg naltrexone plus 4 mg naloxone, intranasally.
a
Geometric mean (%CV) for all except median (range) for Tmax.
b
N = 10.