Abstract
The pharmacokinetics of ketamine in analgesic doses after intravenous, intramuscular, and oral administration was investigated in healthy volunteers. Plasma ketamine concentration-time curves were fitted by a two-compartment open model with a terminal half-life of 186 min. Absorption after intramuscular injection was rapid and the bioavailability was 93%. However, only 17% of an oral dose was absorbed because of extensive first-pass metabolism. Simultaneous measurements of the elevation of pain threshold in an ischemic exercise test showed a marked effect for 15-60 min after intramuscular injection, but little or no effect after the oral solution. Pain threshold elevation occurred at plasma ketamine concentrations above 160 mg/ml.
| Original language | English |
|---|---|
| Pages (from-to) | 539-542 |
| Number of pages | 4 |
| Journal | Journal of Pharmaceutical Sciences |
| Volume | 71 |
| Issue number | 5 |
| Publication status | Published - 1982 |