Flumazenil potentiation of postoperative morphine analgesia.
OBJECTIVE
The goal of this study was to test the effect of concomitant administration of flumazenil (FL) and morphine (MO) on immediate postoperative analgesia and the MO requirement to control pain in human beings.


METHODS
Thirty-six patients undergoing inguinal hernioplasty under lidocaine epidural anesthesia were enrolled in this double-blind, randomized, controlled study. On the first complaint of pain, either MO (2 mg) only or MO (2 mg) plus FL (0.2 mg) was administered. Additional doses of the same medications administered via a patient-controlled analgesia device with a 10-minute lockout period were available thereafter. The study continued for 2 hours after the loading doses of the medications were administered, with an additional 2-hour period of observation.


RESULTS
Thirty-two patients completed the study. Both groups reached a similar satisfactory equianalgesic state (2 in a 0-10 visual analogue scale). The MO plus FL group consumed 9.5 +/- 1.1 mg of MO versus 14.1 +/- 1.1 mg of MO (p < 0.001) in the MO only group. The MO plus FL patients were subjectively (visual analogue scale) more comfortable and less sedated than the MO patients. "Fine" coordination (using an electronic maze) and "coarse" coordination (measured by transferring a pen from one hand to another as rapidly as possible with both arms placed inside an 80-cm metal frame) in the MO group were worse than in the MO plus FL group. End-tidal CO2 increased and blood pressure decreased in the MO group. There were few and insignificant side effects in the MO group. None of these patients required an MO antagonist, and recovery was prolonged in none.


CONCLUSIONS
Flumazenil afforded lower MO consumption during the immediate postoperative period. Cognitive, hemodynamic, and respiratory functions were better after MO plus FL than after MO alone.
Weinbroum
A A
AA
Department of Anesthesiology and Critical Care Medicine, Tel-Aviv Sourasky Medical Center and the Sackler Faculty of Medicine, Tel-Aviv University, Israel.
Weisenberg
M
M
Rudick
V
V
Geller
E
E
Niv
D
D
D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D004357:Drug Synergism; D005260:Female; D005442:Flumazenil / Q000009:adverse effects / Q000627:therapeutic use*; D018757:GABA Modulators / Q000009:adverse effects / Q000627:therapeutic use*; D006439:Hemodynamics / Q000187:drug effects; D006552:Hernia, Inguinal / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000009:adverse effects / Q000627:therapeutic use*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy* / Q000523:psychology
D000701:Analgesics, Opioid; D018757:GABA Modulators; D005442:Flumazenil; D009020:Morphine