Chronic use of metamizole: not so safe after all?

Metamizole can be used in both short- and long-term pain relief therapies and has a relatively favourable safety profile compared with classic NSAIDs. Metamizole is also infamous because of its potential fatal adverse drug reaction, agranulocytosis. Although this risk varies, it is estimated to occur in less than one million metamizole prescriptions. We describe a case of a 68-year-old patient who developed leukopenia after using metamizole.