SUBHYPNOTIC DOSES OF PROPOFOL DO NOT POSSESS ANTIDOPAMINERGIC PROPERTIES

In order to investigate the possible interactions of propofol with the dopaminergic system, a prospective, randomized, double-blind, placebo -controlled study was performed on the profile of prolactin secretion, since prolactin blood levels are known to increase when dopaminergic receptors are blocked. Ten fasting female patients scheduled to receiv e cancer chemotherapy were allocated to receive either propofol at a r ate of 1 mg . kg(-1) . h(-1) or Intralipid(R) 0.1 ml . kg(-1) . h(-1). The study included two consecutive chemotherapy cycles; each patient received in a random order propofol or Intralipid(R). The infusions we re started 4 h prior to induction of chemotherapy; prolactin blood lev els were determined at time 0, 30, 60, 120, and 240 min (end of the st udy period). The basal prolactin blood levels were 14.2 +/- 4.3 vs 12. 8 +/- 2.7 and 10.7 +/- 1.7 vs 14.0 +/- 3.6 ng/mL at the end of the stu dy for propofol and Intralipid(R), respectively. These results suggest that the antiemetic properties of propofol are not mediated via inter actions with the dopaminergic system.