title: The association between negative affect and opioid analgesia in patients with discogenic low back pain.
abstract: Comprised mainly of depression, anxiety, and high neuroticism, psychopathology diminishes the effectiveness of many chronic pain treatments. But, it is not known if it is associated with diminished opioid analgesia in patients with chronic, noncancer pain. We tested the hypothesis that psychopathology diminishes opioid analgesia in patients with discogenic low back pain in 60 patients not on opioids in a double blind, placebo controlled, random crossover designed trial. Patients were stratified into three groups of psychological symptom severity (LOW, MOD, and HIGH), based on composite scores on depression, anxiety for pain, and neuroticism scales. Subjects were given intravenous morphine (4-6mg dosed by ideal body weight) and placebo in random order on separate visits, and completed serial pain ratings over three hours at each session. With 20 subjects per group, there were nonsignificant differences between groups in the distribution of age, gender, baseline pain (avg. 6.1/10), radicular pain, and morphine dose (5.0mg). For morphine analgesia, using a total pain relief calculation (TOTPAR), the LOW group had 65.1% TOTPAR vs. 41.0% in the HIGH group, P=.026. For placebo analgesia the LOW group had 7.7% TOTPAR vs. 23.5% in the HIGH group, P=.03. A morphine minus placebo analgesia calculation revealed 59.2% TOTPAR in the LOW group vs. 21.7% in the HIGH group, P=.0001. High levels of psychopathology are associated with diminished opioid analgesia in patients with discogenic low back pain. These results have implications for the prescription of oral opioids to patients with chronic low back pain and psychopathology.
authors.affiliation: Brigham and Women's Hospital/Harvard Medical School, Departments of Anesthesiology, Perioperative and Pain Medicine; and Psychiatry, Pain Mangement Center, 850 Boylston Street, Chestnut Hill, MA 02467, USA Amgen Corporation, Thousand Oaks, CA, USA.
authors.forename: Ajay D
authors.initials: AD
authors.lastname: Wasan
authors.forename: Gudarz
authors.initials: G
authors.lastname: Davar
authors.forename: Robert
authors.initials: R
authors.lastname: Jamison
mesh_terms: D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000704:Analysis of Variance; D001526:Behavioral Symptoms / Q000188:drug therapy* / Q000209:etiology; D016022:Case-Control Studies; D018592:Cross-Over Studies; D003710:Demography; D004185:Disability Evaluation; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007275:Injections, Intravenous / Q000379:methods; D016014:Linear Models; D017116:Low Back Pain / Q000145:classification / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009020:Morphine / Q000008:administration & dosage*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D010555:Personality Inventory / Q000706:statistics & numerical data; D015990:Placebo Effect; D011581:Psychological Tests; D018434:Sickness Impact Profile; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine