Table 1.
Pharmacokinetic values for synephrine and caffeine under resting and exercise conditions
| Parameter | Synephrine | Caffeine | ||
|---|---|---|---|---|
| Rest | Exercise | Rest | Exercise | |
| Cmax | 1.75 ± 0.79 ng ml−1 | 1.86 ± 0.72 ng ml−1 | 5.9 ± 1.9 μg ml−1 | 5.9 ± 1.4 μg ml−1 |
| Tmax (min) | 126 ± 41 | 108 ± 32 | 144 ± 51 | 135 ± 32 |
| AUC(0–∞) | 427.9 ± 172.6 ng min−1 ml−1 | 466.4 ± 222.1 ng min−1 ml−1 | 3534 ± 1956 µg min−1 ml−1 | 3723 ± 1681 μg min−1 ml−1 |
| CL/F | 60.0 ± 32.5 l min−1 | 55.8 ± 27.5 l min−1 | 102.6 ± 36.4 ml min−1 | 94.3 ± 34.5 ml min−1 |
| T1/2 (h) | 2.56 ± 0.80 | 2.64 ± 1.11 | 5.96 ± 1.87 | 6.38 ± 1.92 |
Values are means ± standard deviations, except for Tmax for which medians are shown (n = 10). Cmax, maximum plasma concentration; Tmax, time to maximum plasma concentration; AUC(0–∞), area under the plasma concentration vs. time curve extrapolated to infinity; CL/F, clearance divided by bioavailability; V/F, apparent volume of distribution divided by bioavailability; T1/2, elimination half-life. All comparisons of exercise vs. resting values were nonsignificant (P-value >0.05 by paired Student's t-tests).