!3404 EFFECTS OF OPIATES IN POST-OPERATIVE PAIN: MULTIPLE MECHANISMS OF ACTION. and R. Melsack*, '

F.V. ABBOTT1 EVIDENCE FOR 593 Poster , W.T. Zackon*3 Wednesday

School of Nursing and 'Dep5. of Psycholog 1

Stuart 1 McGill University, Montreal, PQ, Canada and ‘Dept. of Psy- cology, Kingston, Ont, Canada.

Aim of Investigation: The analgesic effects of meperidine, anileridine, codeine plus acetominophen and codeine were assessed with the McGill Pain

Questionnaire (MPQ) to determine if the pattern of pain reduction was simi- lar for these drugs.

Methods: The MPQ was administered to 65 patients 1-4 days after surgery

at the time that a request for analgesic medication was made, The nurse then administered an analgesic on the basis of standing orders. One hour later the MPQ was readministered. The reduction in pain score for each of the 20 MPQ categories was calculated. In addition, a group of 18 student volunteers were asked to rate the 20 MPQ categories as bright-"phasic" or

dull-"tonic". Results: All drugs produced significant analgesia. However, the reduc-

tions for the 20 MPQ categories were highly variable and ranged from no relief to complete relief. The pattern of analgesia was extremely similar

for meperidine and anileridine (r=.81, p<.Ol). Furthermore, the degree of reduction by category correlated positively with the number of students

rating a category bright-"phasic" (r:.53, pC.05). The effects of codeine plus acetominophen were mildly correlated with those of meperidine (rm.51, p<.OS) while effects of codeine alone were not (r-42, ns). Neither codeine nor codeine plus acetominophen effects were related to the bright-"phasic"

quality.

Conclusions: Different analgesic drugs produce different profiles of analgesic effects. the

This may allow anal esic medication to be matched to

! ain experienced by patients. l? the data also indicate that

opia es have multiple mechanisms Furt ermore,

of action.

SLOW RELEASE MORPHINE IN CHRONIC PAIN. T. Houston*, [-~594 Poster A. Dingwall*, I.M.C. Clarke, Regional Pain Relief Centre, Wednesday Hope Hospital, Salford M6 8HD, England. (SPON: P. Lee) Stuart 2

A slow release form of morphine sulphate has been available in the United Kingdom for the last 5 years and is soon to be introduced in other parts of the world. This preparation appears to offer advantages over currently available narcotic analgesics in terms of ease of administration, enhanced patient compliance and freedom from adverse effects.

To assess this product sixty-four patients who required long term opioid analgesia and for whom complete records were available were studied from the time of presentation to the pain relief center until death (in the case of cancer pain) or plateau analgesia and rehabilitation.

Ten percent of the study group had chronic pain due to non-cancer organic pathology unresponsive to other forms of pain therapy.

Results are presented with special reference to incidence of side effects, patient acceptance, and efficacy compared to other analgesia regimes.

It is suggested that slow release morphine sulphate represents a major advance in narcotic analgesia for chronic pain especially where this is due to non-neoplastic disease.