E-DRUG: Dipyrone revisited (2)
---------------------------------------------
I've not much knowledge about the safety of paracetamol injection for an antipyretic effect. It is not common and there are not much pharmaceutical forms for this purpose.
However I want to comment on the decision of Nigerian regulatory authorities. It is hard to understand what may be a reason for such a decision. We have read a lot on the safety issue of dipyrone (metamizol) from e-drug contributors and as well as from the literature. Some were in favor of dipyrone usage, some absolutely not.
The discussion is running for a long time and there are still concerns about the risk of agranulocytosis during dipyrone treatment. However, my question is "Is there any new information which is not published in the literature or is it the same background we know from the Swedish study report (Eur J Clin Pharmacol. 2002 Jul;58(4):265-74. Agranulocytosis and other blood dyscrasias associated with dipyrone (metamizole). Hedenmalm K, Spigset O.)?"
In my opinion the risk of agranulocytosis during dipyrone treatment is very rare. Recently published reports investigating the risk of agranulocytosis in different countries are good evidences for the safety of dipyrone:
Arch Intern Med. 2005 Apr 25;165(8):869-74. Population-based drug-induced agranulocytosis. Ibanez L, Vidal X, Ballarin E, Laporte JR.
Eur J Clin Pharmacol. 2005 Jan;60(11):821-9. Agranulocytosis associated with dipyrone (metamizol). Ibanez L, Vidal X, Ballarin E, Laporte JR.
Med Sci Monit. 2004 Sep;10(9):PI93-5. A prospective study of the incidence of agranulocytosis and aplastic anemia associated with the oral use of metamizole sodium in Poland. Maj S, Centkowski P.
Since we know that some population are more susceptible to dipyrone, I wonder if there is any evidence on, whether Nigerian population belongs to the susceptible population one or not?
My opinion is that a very safe and strong medicine is going to be lost just because it is no more protected by patent as well as the pharmaceutical industry. Dipyrone has many generic preparations and consequently became a cheap and orphan drug from the pharmaceutical companies point of view.
We have alternative analgesic, antipyretic drugs on the market. What is being intensively discussed is "Do we still need them" and this is written as editorial comments in Clin Pediatr. 2001 Jun;40(6):325-6, by Berlin "Are we losing good drugs?" and Sao Paulo Med J. 2005 May 2;123(3):99-100, by Bensenor "Dipyrone and blood dyscrasia revisited: "non-evidence based medicine".
I urge the E-drug readers to have a look on these papers.
Especially in countries that have low income are more interested to ban pharmaceuticals from the market. The same had happened before and the reason is always safety issues. However I'm concerned about these procedures. My suggestion is that the main issue is the need of keeping room for new drugs which are safer (?) or more expensive. Please notice the recent "coxibs" issue.
We are talking about a drug which is introduced in clinical practice in 1922. We know a lot about it and we learn more and more about its beneficial effects. Since there is no more protection by its producers, it is our business to improve the knowledge of the population about dipyrone and similar other drugs which have the same fate.
I would be very much interested about the pharmacoeconomic analysis of changing the practice from parenteral dipyrone to parenteral paracetamol treatment.
Greetings to all colleagues of E-drug.
Hakan Ergün
(Associate Professor)
Ankara University Faculty of Medicine
Department of Pharmacology and Clinical Pharmacology
Ankara, Turkey
E-mail: hergun@medicine.ankara.edu.tr