Agranulocytosis and anaphylaxis on metamizol (NOVALGIN, generics): A 71-year old woman with rheumatoid arthritis and chronic treatment refractory pain syndrome is admitted to hospital for faintness accompanied by tachycardia and hypoglycaemia. Severe pancytopenia and markedly elevated C-reactive protein are detected in hospital. The patient is taking metamizol (NOVALGIN, generics) regularly and has been taking methotrexat (LANTAREL, generics) for 15 years up to a week prior to admission. Despite discontinuation of metamizol and administration of granulocyte colony-stimulating factors, folinic acid and antibiotics as well as transfusion of platelet concentrate, blood cells remain reduced and the patient dies a few days later with the signs and symptoms of sepsis (NETWORK report 15.877). The Institute for Clinical Pharmacology in Bremen currently reports on two other female patients with impaired haematopoiesis including agranulocytosis on metamizol, which have been recorded since the end of 2009 (NETWORK reports 15.875, 15.876). In parallel to the constantly increasing prescriptions in recent years, there has also been a rise in the number of reports of suspected agranulocytosis on metamizol acquired at the Drug Commission of the German Medical Association (DCGMA) (see figure: STAMMSCHULTE, T., DCGMA 2010). In addition, there are reports on two men with life-threatening anaphylaxis/anaphylactoid reaction accompanied by hypotension on intravenous administration or ingestion of metamizol (NETWORK reports 15.878, 15.879). These occur more frequently particularly in cases of pre-existing hypotension, hypovolaemia or high fever and with increasing dose and rapid intravenous injection (SCHOTT-SEIDENSCHWANZ, I., et al.: Bremer Ärztejournal [Bremer Medical Journal] 2011; 64: 20). The strict restrictions of indication in Germany clearly do not prevent the extensive use of this high-risk agent. Countries such as Sweden or the USA (a-t 2003; 34: 38) show that pain therapy and reduction of fever are still possible without metamizol, - ed.

Figure: Metamizol - reports (DCGMA) of suspected
agranulocytosis and growth in prescribing figures