Fig. 2. Individual plasma concentrations (C^P) of morphine  (left ), morphine-6-glucuronide  (middle ), and morphine-3-glucuronide (  right ) after an intravenous 90-s morphine infusion. All but two subjects received 0.2 mg/kg morphine; two subjects inadvertently received 0.13 mg/kg (represented by  dashed lines ) .