Metamizole Use in Children: Analysis of Drug Utilisation and Adverse Drug Reactions at a German University Hospital between 2015 and 2020

Abstract

Background Metamizole use is controversially discussed due to its potentially serious adverse drug reactions (ADRs). In Germany, however, it remains a popular analgesic and antipyretic drug. Objective The aim of this study was to discuss the safety profile of metamizole in children by analysing the inpatient prescription patterns and presenting the metamizole-related ADRs at a paediatric hospital between 2015 and 2020. Methods Metamizole utilisation data were retrospectively analysed from electronic medical records. ADRs were prospectively recorded via the hospital’s stimulated reporting system and analysed accordingly. Patients aged < 18 years admitted to one of the general wards of the department of paediatrics and adolescent medicine of a German university hospital between June 2015 and May 2020 who received at least one drug therapy within their inpatient stay were included in the analysis. Causality of ADRs was rated according to the World Health Organisation causality assessment. Results In 31.7% (3759/11,857) of the inpatient stays of 7809 patients, metamizole was administered. Metamizole exposure was highest in adolescents (37.9%) and lowest in newborns (9.9%). Overall, metamizole was administered parenterally in about 90%. Three cases of agranulocytosis, one allergic shock and one rash with possible or higher causality to metamizole treatment were reported. Three of these occurred prior to hospitalisation. All patients recovered without remaining harm. Discussion Metamizole is commonly used in paediatric inpatients in Germany. Serious ADRs occur but rarely. Continuous monitoring of drug therapy through, for example, stimulated reporting systems ensures that serious ADRs are detected, and appropriate interventions can be introduced.

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“…Metamizole has been introduced into our clinical practice as a rescue drug because, besides its excellent analgesic properties, it exhibits synergism with non-steroidal anti-inflammatory drugs, paracetamol, and opioids [ 29 ]. To minimize the risk of agranulocytosis, we have used this medicinal product for a short time [ 30 ]. The surveys conducted by Fieler et al [ 31 ] and Witschi et al [ 32 ] confirmed that metamizole is also frequently used by German anesthesiologists in children in the perioperative setting and cases of serious adverse drug reactions such as hemodynamic, anaphylactic, and respiratory reactions (0.3%) or agranulocytosis are very rare (0.14%).…”

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“…Metamizole inhibits prostaglandin synthesis, mainly by inhibiting cyclooxygenase 1 (COX-1) and COX-2; moreover, it modulates nociception induced by substance p. Additionally, it affects the cannabinoid system (analgesic and antipyretic action). its spasmolytic action results from inhibition of adenosine reuptake in the CNS and its influence on the cannabinoid system [85][86][87][88][89]. thanks to the relaxing smooth muscle effect, metamizole is particularly useful when pain is accompanied by a spastic component.…”

“…Additionally, it affects the cannabinoid system (analgesic and antipyretic action). its spasmolytic action results from inhibition of adenosine reuptake in the CNS and its influence on the cannabinoid system [ 85 – 89 ]. thanks to the relaxing smooth muscle effect, metamizole is particularly useful when pain is accompanied by a spastic component.…”

Sodium Metamizole: Regulatory Status around the World, Safety Problems and Medication Errors

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