Introduction:
Acute postoperative pain is the pain present in surgical patients
following the procedure1. Pre-emptive analgesia
describes the attempt to control pain in the pre-incisional period. It
aims to prevent central hyperexcitability, which tends to amplify in the
postoperative period2. A recent review of systematic
reviews concluded that evidence for the efficacy of various drugs and
strategies for managing postoperative pain in children is still
inconclusive3. Dipyrone, however, was not evaluated in
this review.
Dipyrone is effective in postoperative pain in children. There are 8
clinical trials that have used it alone or in combination with other
medications4-11. It is one of the most widely-used
analgesics in the postoperative period in several
European12-13, African14 and Latin
American countries15. However, there is concern about
its potential for associated anaphylaxis and
agranulocytosis16. Its use is banned in more than 20
countries.
The real incidence of these adverse effects, however, is low. In a
multicentre study involving more than 1,177 children treated with
dipyrone in the postoperative period, the incidence of serious adverse
effects was less than 0.3%, with no case of
agranulocytosis17. Two studies, one involving several
European countries (Germany, Italy and Spain)18 and
another only in the city of Berlin19, estimated an
incidence of agranulocytosis of 1.1 per million inhabitants/year and
0.96 cases per million inhabitants/year, respectively. In the city of
Barcelona, the estimate was 0.56 cases per million
inhabitants/year20. The risk of severe complications
and the availability of alternatives continue to contraindicate its use
in the opinion of some21. Despite the ban in several
countries, dipyrone is the most widely used painkiller in the
postoperative period for children in Brazil, perhaps due to its low cost
and the lack of an injectable form of paracetamol, at least until April
202022. In terms of oral analgesic medication, in
contrast with the preference for paracetamol in different regions of the
world23, in our country it is the most widely-used
self-medication, as it is sold as an over-the-counter
medicine24.
Dipyrone has been used for decades in children in the postoperative
period of tonsillectomy. This surgery is the 2nd most common outpatient
procedure in the USA25,26. Its main complication is
pain that can lead to a reduction in oral intake, dehydration and weight
loss27. The latest North-American Clinical Practice
Guideline on Tonsillectomy contains 2 strong recommendations about
analgesia: 1. to use analgesics in the post-operative period and 2. the
contraindication in the use of opioids, especially in children under
1227. This latter recommendation is based on the FDA’s
warning of the risk of respiratory depression and death using
codeine28. In context of tonsillectomy, intravenous
dipyrone could represent an alternative to opioids, where odynophagia
with consequent difficulty in swallowing is almost universal.
The aim of this study was to review the analgesic use of dipyrone in the
postoperative period of tonsillectomy in children.