Agranulocytosis after use of metamizol – can this frequently underestimated risk be reduced by improved documentation?

Introduction:

Metamizole was the third most common drug prescribed in Germany in 2017 in spite of the known risk of agranulocytosis and the strict indication.

Although mandatory according to the prescribing information of metamizole, regular blood cell counts are not performed in up to 50% of the patients with long-term use of this drug.

Methods:

Retrospective analysis of three cases metamizole-induced agranulocytosis over a period of three years (2016 – 2018) in a universitary ENT department. Two patients were men (age of diagnosis 25 and 71 years) and one patient was an 85-years-old-woman.

Results:

Agranulocytosis after use of metamizole is a serious adverse drug reaction that may affect patients of all ages. Frequently, only distinct clinical symptoms such as temperature of unknown origin in combination with abscesses result in the detection of a metamizole-induced agranulocytosis. Possible reasons could be both a lack of awareness of the physician to this drug reaction and/or missing documentation after metamizole administration independent of the duration.

Conclusions:

Agranulocytosis is a dangerous or even deadly adverse drug reaction after use of metamizole. Although the risk of agranulocytosis appears to increase with duration of use, we would recommend the documentation of even a single administration of metamizole. This may facilitate early diagnosis of metamizole-induced agranulocytosis and thus prevent the onset of severe complications with possible lethal outcome.

Publication History

Publication Date:
23 April 2019 (online)