[A new formulation of etomidate in lipid emulsion--bioavailability and venous provocation]

In a prospective, randomized study of 16 volunteers, a new galenic formulation of the induction hypnotic etomidate in lipid emulsion was compared with the commercial form in propylene glycol (Hypnomidate). After 0.3 mg/kg etomidate plasma levels (HPLC) and hypnotic effects (visual EEG analysis) of both formulations were almost identical. Onset of action occurred after 41.6 s in the propylene glycol group (group I) and 35.6 s in the lipid emulsion group (group II). The hypnotic effect (greater than or equal to D0) lasted 7 min 20 s in group I and 6 min in group II. Plasma levels in group I decreased from 630 ng/ml after 2 min to 170 after 8 min and 37 after 130 min. With group II the plasma levels decreased from 770 ng/ml after 2 min to 150 after 8 min and 42 after 130 min (Fig. 1). In the propylene glycol experiment, 4 of 8 volunteers reported pain on injection. Within 7 days 4 persons developed phlebitis or thrombophlebitis. One showed signs of an allergic reaction (urticaria). With the new formulation of etomidate in lipid emulsion, neither venous sequelae nor allergic reactions were observed in any of the 8 volunteers (Table 2).