Table 1.

Stability of ketamine and its metabolites in human blood.

Time of storage, minTemperatureConcentration (mean ± SD), μg/L (n = 5)% of initial concentration, mean ± SDMann-Whitney test1
Ketamine
  04 °C445 ± 23100 ± 5.2
Ambient423 ± 11100 ± 2.6
  304 °C423 ± 2695 ± 6.1NS2
Ambient414 ± 1098 ± 2.4NS
  604 °C432 ± 1597 ± 3.5NS
Ambient428 ± 10101 ± 2.3NS
 1204 °C442 ± 2199 ± 4.7NS
Ambient426 ± 35101 ± 8.2NS
NK
  04 °C477 ± 25100 ± 5.2
Ambient466 ± 13100 ± 2.8
  304 °C464 ± 2597 ± 5.4NS
Ambient455 ± 1098 ± 2.2NS
  604 °C464 ± 1997 ± 4.1NS
Ambient494 ± 20106 ± 4.0NS
 1204 °C484 ± 21101 ± 4.3NS
Ambient450 ± 3297 ± 7.1NS
DHNK
  04 °C357 ± 22100 ± 6.2
Ambient375 ± 11100 ± 2.9
  304 °C243 ± 1768 ± 7.0Very significant; P = 0.0079
Ambient380 ± 34102 ± 8.9NS
  604 °C215 ± 860 ± 3.7Very significant; P = 0.0079
Ambient411 ± 37110 ± 9.0NS
 1204 °C188 ± 1153 ± 5.8Very significant; P = 0.0079
Ambient408 ± 55109 ± 13.4NS
  • 1 Compared with values at 0 min (t0).

  • 2 NS, not significant.