Effect of morphine on experimental pain and measures of clinical pain in chronic pain patients

S155 EFFECT OF MORPHINE ON EXPERIMENTAL PAIN AND MEASURES OF 192 Po CLINICAL PAIN IN CHRONIC PAIN PATIENTS, P.J. Wolskee*, R.H. Tuesday Gracely, M.J. Sayer and R. Dubner (SPAN: M. Hoffert), Neurobiol. & Anesthesiol. Br., NIDR,NIH, Bethesda, MD 20205 USA Morphine reduces both the sensory intensity and unpleasantness responses to thermally-induced experimental pain in chronic pain patients. This study correlates experimental pain with clinical pain before and after morphine administration in a group of patients with chronic pain varying in etiology. Five drug-free patients assessed the sensory intensity and unpleasanto o ness of thermally-induced experimental stimuli (46 -51 C) in separate sessions by choosing verbal descriptors from randomized lists before and after the double blind administration of morphine (mean dose=t2.4 mg) or saline placebo. In all sessions, subjects also completed 7 clinical questionnaires: the visual analogue scales of sensory intensity (SI) and unpleasantness (UNP), the McGill pain questionnaire, the Differential Descriptor Scale (DDS) of SI and UNP, and the Verbal Descriptor Check List (VDCL) of SI and UNP. Morphine administration significantly reduced the SI (t=3.85,p<.05) and UNP (t=4.16,p<.01) of experimentally-induced stimuli in comparison to placebo. All clinical measures showed a significant decrease after morphine administration in comparison to placebo (Wilcoxin sign rank test, p values of <.05 to <.01). The agreement of the experimental and clinical pain results enhances the use of the verbal descriptor scaling of contact heat for the assessment of pain control methods. The agreement of the newly-developed DDS and VDCL with the established visual analogue scales and McGill questionnaire supports their use in the measurement of clinical pain. Using these scaling methods, we have established a consistent finding in the effect of morphine administration on experimental and clinical pain. MEASUREMENT OF PAIN IN GENERAL PRACTICE. Comparisons of 193 Po fluproquazone, diflunisal and aspirin. E.C. Huskisson, Dept.of Rheumatology,St. Bartholomews Hospital,London, Tuesday E.G.M.Cameron,Sandoz U.K.,SPON B.Von Graffenried,Sandoz A.G. Basle. Aim of Investigation: Methods of measuring pain have been developed mainly in interested, hospital-based clinics, but are now being applied to cli~cal trials in general practice. Two studies are discussed, the first comparing diflunisal and aspirin (Huskisson, E.C. 1979 The Practitioner 223, 415-418) using a simple descriptive pain relief scale and the second comparing fluproquazone with diflunisal using visual analogue scales. In the second study, fluproquazone in a dose of iOOmg t.d.s, was compared with diflunisal in a dose of 250 - 50Omg b.d. in 378 patients. Method: Treatment was supplied as identical capsules. Measurements of efficacy included pain relief, assessed daily by the patient, using a visual analogue scale and an overall assessment of efficacy by patient and physician. Side effects were noted with reasons for termination of treatment where appropriate. Results: There were no significant differences between fluproquazone and diflunisal. The time course of the improvement produced by the two drugs was identical. Thirty-one patients receiving diflunisal and nineteen receiving fluproquazone reported side effects, mostly gastrointestinal and moderate to mild in severity. Six patients in each group stopped treatment because of side effects. Conclusion: Visual analogue scales proved to be a satisfactory method of assessment and their advantages and disadvantages are discussed in the light of this experience.