[e-drug] dipyrone obituiry

[lo@euronet.nl]

E-DRUG: dipyrone obituiry
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[dipyrone or metamizole has been a controversial analgesic since 1970's,
when it was found to cause agranulocytosis and irreversible shock. The
famous "Boston" study of 1986 had conflicting data about the risk for
agranulocytosis, and the manufacturer (Hoechst) claimed it was safe.
Germany first made it a prescription-only drug, but later banned all
combination products as doctors were unaware that dipyrone was "hiding" in
them. Unfortunately drug companies continued to manufacture and sell
dipyrone combinations in Eastern Europe and developing countries. Some
countries kept the single ingredient for "severe pain in cancer" as a last
resort.
The final study about dipyrone's unsafety has now appeared in Sweden, and
shows that it causes agranulocytosis in 1 per 1439 prescriptions. This is
obviously unacceptable for an analgesic! Let us hope this is enough
evidence to bury this unsafe drug once and for all. WB]

dear E-druggers,

Dipyrone (metamizol or noramidopyrine) is a controversial analgesic,
related to the group of NSAIDs. Like the parent compound amidopyrine
(aminopyrine, "Pyramidon") it fell in disrepute in the late sixties because
it caused serious bone marrow dyscrasias with a relatively high mortality.
For that reason it was never registered in the USA and in the UK, and in
1974 it was withdrawn from the Scandinavian market.



However, the incidence of this complication was hotly disputed by the two
main German producers, Hoechst and Boehringer-Mannheim, who organized a
large worldwide trial, published in 1986. From these data an incidence of
agranulocytosis of 1:1.500.000 users was calculated.

A number of papers contested the data because of a number of errors in data
collection and inadequate supervision.



Because the drug was an effective, cheap, and seemingly rather harmless
analgesic it was again released on the Swedish market under strict
conditions of surveillance of adverse reactions in 1995, and four years
later suspended for the second time because of the high incidence of bone
marrow dyscrasia.



The full results have now been published by the Swedish Medicinal Products
Agency (Hedenmalm K, Spigset O: Agranulocytosis and other blood dyscrasias
associated with dipyrone (metamizole). Eur J Clin Pharmacol
2002;58:265-274), and the full results will shortly be summarized by the
WHO Pharmaceutical Newsletter in order to correct the wrong impression
recently given by the inadvertent publication of a Brazilian review by
Wong.



The Swedish authors conclude that dipyrone causes serious bone marrow
disorders with an incidence of at least 1:1439 users, a total of 15 with
fatal and a further 37 with non-fatal outcome: Agranulocytosis only in
resp. 10 and 33. Data are very similar to those obtained in the fifties
with aminopyrine.


Best wishes,

Dr.L.Offerhaus
Koedijklaan 1a
NL-1406 KW Bussum
The Netherlands
Phone +31-35-6923288 Fax +31-35-6923277
lo@euronet.nl



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