title: Preoperative pregabalin does not reduce propofol ED(50): a randomized controlled trial.
abstract: BACKGROUND
  In many studies, gabapentinoids, such as pregabalin, have been shown to reduce preoperative anxiety. This anxiolysis is often accompanied by sedation, one of the most frequent side effects of pregabalin. We hypothesized that pregabalin taken preoperatively could reduce propofol requirements for induction of general anesthesia.
  
  
  METHODS
  A randomized double-blind placebo-controlled trial was conducted after approval by the local ethics committee. Fifty women aged 18-40 yr, American Anesthesiologists Society physical status I and II, and scheduled to undergo elective laparoscopic gynecologic procedures were enrolled after written consent. Treatment group patients were given pregabalin 150 mg po one hour before surgery while patients in the control group received a placebo. The primary outcome was the propofol dose required to achieve a targeted anesthetic depth in 50% of the population, i.e., effective dose (ED)50. The ED50 was estimated using Dixon's up-and-down methodology. The targeted anesthetic depth was defined based on predetermined entropy monitoring values (State Entropy [SE] < 50 and Response Entropy [RE]-SE < 10). As a secondary outcome, we tested if pregabalin reduced pre-induction anxiety levels which were measured on a 0-100 scale.
  
  
  RESULTS
  The propofol ED50 was not statistically different between the pregabalin group (mean 1.33 mg·kg(-1); 95% confidence interval [CI] 1.23 to 1.43) vs the placebo group (mean 1.37 mg·kg(-1); 95% CI 1.28 to 1.46); P = 0.19. Also, pre-induction anxiety level was not different between groups (median 31; interquartile range [IQR] [10-52] vs median 42; IQR [4-71], respectively; P = 0.41).
  
  
  CONCLUSIONS
  Preoperative pregabalin does not reduce propofol requirements in a population of healthy young women undergoing laparoscopic gynecologic procedures. This study failed to show a pre-induction anxiolytic effect of pregabalin in such a population. This trial was registered at www.clinicaltrials.gov (NCT01158859).
authors: Department of Anesthesiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12e Avenue Nord, Sherbrooke, QC, J1H 5N4, Canada.
authors: François
authors: F
authors: Moreau-Bussière
authors: Jonathan
authors: J
authors: Gaulin
authors: Véronique
authors: V
authors: Gagnon
authors: Yanick
authors: Y
authors: Sansoucy
authors: Etienne
authors: E
authors: de Médicis
mesh_terms: D000293:Adolescent; D000328:Adult; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology; D000768:Anesthesia, General / Q000379:methods; D018686:Anesthetics, Intravenous / Q000008:administration & dosage* / Q000494:pharmacology; D001007:Anxiety / Q000517:prevention & control; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D017558:Elective Surgical Procedures / Q000379:methods; D005260:Female; D013509:Gynecologic Surgical Procedures / Q000379:methods; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D000069583:Pregabalin; D011300:Preoperative Care / Q000379:methods; D015742:Propofol / Q000008:administration & dosage* / Q000494:pharmacology; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000700:Analgesics; D018686:Anesthetics, Intravenous; D000069583:Pregabalin; D005680:gamma-Aminobutyric Acid; D015742:Propofol