(51) The Use of Metamizol and Other Non-Opioid Analgesics in Switzerland Between 2014 and 2019: A Descriptive Study

Friday, August 26, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 382

Presenting Author(s)

Stephan Gut
– University of Basel, Basel, Basel-Stadt, Switzerland

Co-Author(s)

Marlene Rauch
– Basel Pharmacoepidemiology Unit, Division of Clinical Pharmacy and Epidemiology, Department of Pharmaceutical Sciences, University of Basel, Switzerland
Carola A Huber
– Department of Health Sciences, Helsana Insurance Group, Zürich, Switzerland, Switzerland
Manuel Haschke
– University Hospital Bern, Switzerland
Jan Gärtner
– Palliative care center Hildegard, Basel, Switzerland
Christoph Meier, Prof Dr
– Basel Pharmacoepidemiology Unit, Division of Clinical Pharmacy and Epidemiology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland, Switzerland
Julia Spoendlin
– Basel Pharmacoepidemiology Unit, Division of Clinical Pharmacy and Epidemiology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland, Switzerland

Background: Metamizol has been withdrawn or withheld from the market in many countries (e.g. France, USA, UK) due the risk of agranulocytosis. In Switzerland, metamizol is among the most frequently prescribed non-opioid analgesic drugs (NOADs).

Objectives: To investigate the use of metamizol and other NOADs in Switzerland over time, and to characterize users of different NOADs with regard to age and co-medications.

Methods: We conducted a retrospective descriptive study using the claims database of the largest Swiss health insurance company (Helsana). We identified all claims (ATC-codes) of metamizol, ibuprofen, diclofenac, and paracetamol in patients aged 18 years or older. We evaluated the number of dispensed defined daily doses (DDD) of each NOAD from 2014 to 2019. To characterize users of different NOADs, we identified the first claim of each NOAD of interest (metamizol, ibuprofen, diclofenac and paracetamol) per patient in 2019. Among four resulting cohorts, we excluded patients with < 180 days of enrollment prior to this first claim. We captured patients’ age and whether they had claimed (yes/no) oral anticoagulants (OA), platelet inhibitors (PI), antihypertensives (AH) or glucose lowering drugs (GL) within 180 days prior to this first NOAD claim.

Results: Paracetamol was the most frequently claimed NOAD (792’553 DDD/100’000 patients in 2014), without relevant change until 2019 (+4%). We quantified 13’945 claimed DDD of metamizol per 100’000 patients in 2014, with the largest increase of 80% to 20’136/100’000 in 2019 (4th most frequently claimed NOAD in 2019). The number of claimed DDD (/100’000) of ibuprofen steadily increased by 23% between 2014 (375'075) and 2019 (457'982), whereas those of diclofenac decreased by 21% from 421'266 in 2014 to 335'492 in 2019. Metamizol users had the highest median age of 57 years (y), interquartile range (IQR) 41y-73y, followed by diclofenac users (55y, 41y-68y), paracetamol users (54y, 37y-71y), and ibuprofen users (46y, 33y-60y). Metamizol users more frequently claimed OA (13%) compared to users of other NOADs (5% ibuprofen, 6% diclofenac, 10% paracetamol), PI (18%) (8% ibuprofen, 13% diclofenac, 16% paracetamol), AH (40%) (22% ibuprofen, 32% diclofenac, 36% paracetamol) and GL (11%) (6% ibuprofen, 8% diclofenac, 10% paracetamol) in the 180 days before the first NOAD claim in 2019.

Conclusions: Metamizol is a popular and increasingly used NOAD in Switzerland, which seems to be preferentially prescribed to elderly patients with cardiovascular/metabolic comorbidities and/or undergoing anticoagulant pharmacotherapy. Given its incompletely understood safety profile, safety studies for metamizol are needed.