Cognitive-affective and somatic side effects of morphine and pentazocine: side-effect profiles in healthy adults.
OBJECTIVE
The side effects of opioids have been widely investigated, but it is unknown whether the subjective effects of mu agonists and mixed action opioids produce similar symptom profiles. This study examined the structure and predictive validity of somatic and cognitive/affective side-effect profiles of morphine and pentazocine using the Somatic Side Effects Questionnaire and the Cognitive and Affective Side Effects Questionnaire.


METHODS
The subjects were 122 female and 90 male healthy volunteers that received an intravenous bolus administration of either 0.08 mg/kg of morphine or 0.5 mg/kg pentazocine. Pre- and post-drug experimental pain testing was also performed. Exploratory and confirmatory factor analysis resulted in similar factor structures for both drugs.


RESULTS
The most frequently reported side effects across both drugs involved feeling relaxed, sedation, and feeling in control. At equianalgesic doses, pentazocine had greater aversive side effects than morphine, whereas morphine was more associated with feelings of control and euphoria. For both drugs, females reported greater frequency of negative side effects than males. Using cluster analysis, we identified similar symptom profiles for each drug. These drug-related side-effect profiles were linked with analgesic responses. Specifically, groups that had a more positive side-effect profile experienced the greatest analgesic effect based on changes in ischemic pain sensitivity.


CONCLUSIONS
These findings have implications for decisions regarding opioid management of acute, chronic, and malignant pain conditions.
Riley
Joseph L
JL
Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, FL 32610-3628, USA. jriley@dental.ufl.edu
Hastie
Barbara A
BA
Glover
Toni L
TL
Fillingim
Roger B
RB
Staud
Roland
R
Campbell
Claudia M
CM
D000293:Adolescent; D000328:Adult; D000339:Affect / Q000187:drug effects*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects*; D016000:Cluster Analysis; D003071:Cognition / Q000187:drug effects*; D004311:Double-Blind Method; D005059:Euphoria / Q000187:drug effects; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006993:Hypnotics and Sedatives; D007275:Injections, Intravenous; D008297:Male; D015233:Models, Statistical; D009020:Morphine / Q000008:administration & dosage / Q000009:adverse effects*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D010423:Pentazocine / Q000008:administration & dosage / Q000009:adverse effects*; D011312:Pressure; D012727:Sex Characteristics; D055815:Young Adult
D000701:Analgesics, Opioid; D006993:Hypnotics and Sedatives; D009020:Morphine; D010423:Pentazocine