Advantages and Problems with Non-Opioids in Pain Management: Vancouver, Canada, August 19, 1996

17 Pages·1997·0.467 MB·English

by  Michael J. Parnham (auth.)

Advantages and Problems
with Non-Opioids in Pain
Managelllent
Vancouver, Canada, August 19, 1996
Springer Basel AG
A CIP catalogue record for this book is available from the Library of Congress, Washington,
D.C., USA
Deutsche Bibliothek - Cataloging-in-Publication Data
Advantages and problems with non-opioids in pain management: Vancouver, Canada, August
19th, 1996 -Springer Basel AG, 1997
ISBN 978-3-7643-5678-1 ISBN 978-3-0348-8865-3 (eBook)
DOI 10.1007/978-3-0348-8865-3
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1997 Springer Basel AG
Originally published by Birkhauser Verlag, Basel, Switzerland in 1997
Printed on acid-free paper produced from chlorine-free pulp. TCF oc
ISBN 978-3-7643-5678-1
987654321
Contents
Introduction ..................................................................................................... 7
Dipyrone in pain management ...................................................................... 9
K. Lehmann
Treatment of post-operative pain without opioids? ................................. 11
N Rawal
Non-opioids in cancer pain management .................................................. 13
s.A. Schug
Comparative safety of non-opioids ............................................................. 17
C. Martinez
Concluding remarks ...................................................................................... 20
7
Introduction
Effective though they are in the treatment of a wide variety of painful con
ditions, opioids are not always the most suitable analgesic therapy. Tried
and tested non-opioid analgesics are frequently preferable, especially for
the treatment of mild to moderate pain, because of their lower incidence of
side-effects or more relevant sites of action.
"Th more we under tand th etiology of pain th more we know that
there ar other drug which might b b tt r than opioid ." (K. Leh
mann)
Many non-opioid drugs are sold in different parts of the world, but not all
are equally available or known to the practising physician.
The place of dipyrone and other non-opioid analgesics in the treat
ment of pain was the topic of an associated symposium held on August 19,
1996, during the 8th World Congress on Pain in Vancouver, Canada. The
highlights of this Hoechst symposium emphasize that dipyrone and other
non-opioid drugs are effective and well tolerated therapies for both acute
and chronic pain.
9
Dipyrone in pain management
Professor K. Lehmann, M.D.
Cologne, Germany
Dipyrone and paracetamol represent the small family of non-acidic, non
opioid analgesics which do not exhibit anti-inflammatory activity. The an
algesic efficacy of dipyrone is broad and comparable to that of the non
steroidal anti-inflammatory drugs (NSAIDs) and tramadol. Because dipy
rone is a weak cyclo-oxygenase inhibitor, its use is not associated with gas
tric irritation, an important advantage for long-term administration.
Uniquely, dipyrone has intrinsic spasmolytic activity. This makes the drug
particularly useful in renal colic pain.
Some 20 years ago, isolated reports linking dipyrone with agranulocy
tosis resulted in its withdrawal from clinical use in the United States and
Sweden. Recent epidemiological studies, however, have shown that the in
cidence of agranulocytosis with dipyrone given for one week is lower than
1 per million users and the drug was reinstated by the Swedish authorities
in 1995. It is recommended that regular blood checks should be made
when using dipyrone on a prolonged basis and that intravenous adminis
tration of dipyrone should be given by slow injection or infusion. On the
other hand, dipyrone represents a positive therapeutic option for patients
at risk for gastric or renal intolerance or respiratory depression. Its avail
ability for oral, intravenous, intramuscular or rectal administration offers
flexibility in clinical use.
In double-blind, placebo-controlled studies in 550 patients, a single 1 g
oral dose of dipyrone has been shown to be more effective than 1 g of
paracetamol in the treatment of post-episiotomy pain or pain following
surgery for removal of a molar tooth.
Advantages of dipyrone have also been observed in comparison to
NSAIDs in the treatment of post-operative pain. For instance, in a recent
double-blind study in 100 patients with post-operative pain, 2.5 g dipyrone
i.m. was equally effective as 30 mg ketorolac i.m. but produced signifi
cantly fewer side-effects.
10 Advantages and Problems with Non-Opioids in Pain Management
Doctor (to whom dipyrone) i available, prefer it to other drugs for
patient who are at ri k of ga trointe tinal or r nal problem. '
This efficacy and better tolerance of dipyrone is also seen in comparison to
opioids. Again in patients with post-operative pain, 2.5 g dipyrone i.v. was
as effective as 100 mg pethidine i.v. or 100 mg tramadol i.v. in relieving
pain, but was preferred by patients because of the lower incidence of side
effects. A combination of 2.5-5 g dipyrone, 300-400 mg tramadol and 2 mg
haloperidol for emesis in a total volume of 500 ml is widely used for treat
ment of post-operative pain in Germany. There is some indication that
dipyrone, given as patient-controlled analgesia (PCA), can reduce opioid
requirements.
The particular value of dipyrone in patients with renal or biliary colic
is confirmed by studies in which it has been shown to be as efficacious as
diclofenac or indomethacin in reducing pain and at 2.5 g i.v. to be more
effective than tramadol or N-butylscopolamine. 2.5 g Dipyrone given i.m.
has also been found to be comparable to diclofenac in relieving sciatic
pain, but with fewer adverse events and a longer duration of action.
In keeping with the WHO ladder concept for the treatment of cancer
pain, it was recommended that dipyrone should be used in combination
with opioids, because the incidence of side-effects is lower than with a
combination of an NSAID and an opioid.
11
Treatment of post-operative pain without
opioids?
Professor N. Rawal, M.D., Ph.D.
Grebro, Sweden
Post-operative pain is still poorly managed. Pain after surgery was found in
80% of patients in a recent survey of 300 hospitals in the USA. Every third
patient undergoing day surgery in a Swedish survey suffered moderate to
severe pain on returning home.
Although opioids are considered to be essential for the post-operative
treatment of patients who have undergone major surgery, there are several
clinical situations in which non-opioids are usefuL
There are imple way of opioid- paring: pre-operative information, a
good ba al medication u e of non- teroidal and dipyrone (a well a )
wound infiltration. '
The main indication for non-opioid analgesics is minor surgery in which
they may be the sole or supplementary analgesics for mild-to-moderate or
even moderate-to-severe pain. Particularly in day-stay surgical patients,
non-opioids have morphine-sparing effects, but few studies have been per
formed to investigate whether opioid side-effects are actually reduced by
these combinations.
In Orebro, where 20,000 patients undergo surgery every year, all pa
tients receive basal non-opioid medication with paracetamoL (Dipyrone
has only recently become available in Sweden). The objective is to have a
painless, alert, feeding and mobile patient who can be sent home as early as
possible, preferably without opioids. Regional anesthesia avoids the haz
ards and discomfort of general anesthesia, but in anxious patients heavy
sedation removes many of the advantages of the regional techniques. In
Orebro, a local anesthetic is almost always infiltrated into the surgical
wound before closure.
12 Advantages and Problems with Non-Opioids in Pain Management
As far as pre-emptive analgesia is concerned, the available clinical data on
the different drugs tested are unconvincing and insufficient to draw mean
ingful conclusions as yet. Equally, the application of "multi-modal" bal
anced analgesia, in which mUltiple drugs and various routes of administra
tion are used, must be viewed with scepticism because of the lack of con
vincing evidence of a reduction of side-effects.
NSAIDs have no clear advantage over non-opioid analgesics such as
paracetamol in post-operative pain. There is no convincing evidence that
NSAIDs provide superior analgesia. Many NSAIDs (e.g. Ketorolac) are
far more expensive and are also associated with a greater risk of adverse
effects. Drugs such as paracetamol and dipyrone, therefore, can playa ma
jor role in our efforts to provide analgesia without opioids.
Psychological factors, such as anxiety and stress, can markedly affect
post-operative pain and in a recent double-blind study, patients who re
ceived specific instructions on how to deal with pain after major abdomi
nal surgery were able to leave hospital 1-2 days earlier than control pa
tients.
In summary, there are a variety of techniques which can be employed
to reduce opioid use in post-operative pain. These include pre-operative
information, good pre-medication, basal medication with paracetamol or
dipyrone, wound infiltration and peripheral nerve blocks.