title: Abuse potential assessment of propofol by its subjective effects after sedation.
abstract: OBJECTIVE
  In this study, we examined the euphoric effect of propofol and its high satisfaction ratio regarding its liability to be abused, particularly in painless procedures, such as colonoscopy.
  
  
  METHODS
  Fifty subjects aged between 18 and 65 years who fulfilled the criteria for ASA 1-2 and were prepared for colonoscopy were enrolled into this study. For intravenous sedation induction, 2 mg/kg propofol was used, and additional injections were administered according to BIS values. After colonoscopy, the subjects were taken to a recovery room and observed for 30 minutes. Patients were interviewed with the modified Brice questionnare regarding the incidence and the content of dreams. A 5-point Likert scale was used to classify their dreams, and the content of the dreams was also recorded. To assess the subjective effects of propofol, the patients were asked to use the Hall and Van der Castle emotion scale; their biological states were also assessed. The patients' feelings regarding propofol were each rated as absent or present. We used the Morphine-Benzedrine Group scale to measure the euphoric effects of propofol. At the end of the study, subjects scored their satisfaction on a five-point scale.
  
  
  RESULTS
  There were no statistically significant differences in sex age, weight, propofol dose, or satisfaction ratio (p>0.05) in the groups, although male patients received a higher dose of propofol and had higher satisfaction ratio. Patients reported no residual after-effects. The incidence of dreaming was 42%. There was no statistically significant difference in dreaming between the sexes, but male patients had a higher dreaming ratio. Dreamers received higher propofol doses and had a higher satisfaction ratio (p>0.05). All dreamers reported happy dreams regarding daily life, and their mean MBG score was 10.5. There was no correlation between MBG scores and propofol doses (r= -0.044, p= 0.761).
  
  
  CONCLUSIONS
  We conclude that propofol functions as a reward; that patients enjoy its acute effects; and that no residual after-effects should arise. We suggest that propofol may carry potential for abuse, and further abuse liability testing is indicated.
authors: Dr. Aysu Hayriye Tezcan, Department of Anesthesia and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors: Aysu Hayriye
authors: AH
authors: Tezcan
authors: Dr. Dilsen Hatice Ornek, Department of Anesthesia and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors: Dilsen Hatice
authors: DH
authors: Ornek
authors: Prof. Dr. Onur Ozlu, Department of Anesthesia and Reanimation, Duzce University Faculty of Medicine, Duzce, Turkey.
authors: Onur
authors: O
authors: Ozlu
authors: Dr. Mustafa Baydar, Department of Anesthesia and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors: Mustafa
authors: M
authors: Baydar
authors: Dr. Nurcan Yavuz, Department of Anesthesia and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors: Nurcan
authors: N
authors: Yavuz
authors: Dr. Nihal Gokbulut Ozaslan, Department of Anesthesia and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors: Nihal Gokbulut
authors: NG
authors: Ozaslan
authors: Dr. Kevser Dilek, Department of Anesthesia and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors: Kevser
authors: K
authors: Dilek
authors: Dr. Aylin Keske, Department of Anesthesia and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors: Aylin
authors: A
authors: Keske
keywords: Abuse potential; Euphoric effect; Propofol; Sedation