Who gets dipyrone (metamizole) in Germany? Prescribing by age, sex and region

Increased Use and Large Variation in Strong Opioids and Metamizole (Dipyrone) for Minor and Major Musculoskeletal Injuries Between 2008 and 2018: An Analysis of a Representative Sample of Swiss Workers

PURPOSE

Musculoskeletal (MSK) injuries are a major contributing factor for chronic pain. To date, little is known how pain medication use in MSK injuries has changed over time. We assessed pain medication prescription for MSK injuries in a representative sample of Swiss workers between 2008 and 2018.

METHODS

Retrospective analysis of the Swiss Accident Insurance Fund (Suva) data. We calculated annual pain medication use, treatment days, and costs associated with pain medication use in minor and major MSK injuries.

RESULTS

In total, 1,921,382 cases with MSK injuries with ≥ 1 pain medication were analyzed. Whereas MSK injuries with ≥ 1 pain medication increased by 9.4%, we observed a larger increase in metamizole (+ 254%), strong opioids (+ 88.4%), coxibs (+ 85.8%), and paracetamol (+ 28.1%). Strong opioids were increasingly used in minor (+ 91.4%) and major (+ 88.3%) injuries. The increase in metamizole (+ 390.6%) and coxibs (+ 115.5%) was larger in minor injuries compared to major injuries (+ 238.7% and + 80.6%, respectively). Medical expenses decreased in all medications except for strong opioids where a substantial increase was observed (+ 192.4% in minor; + 34% in major injuries).

CONCLUSIONS

We observed a disproportionate increase in metamizole, strong opioids, coxibs, and paracetamol prescriptions even in minor MSK injuries between 2008 and 2018. Whereas treatment costs decreased for all pain medications, there was a substantial increase in strong opioids. A more liberal prescription practice of opioids conflict with current evidence-based practice recommendations and need to be addressed by physicians and policy makers.

Medicinal Treatment of Elderly Psoriasis Patients before and after Entering a Nursing Home

Psoriasis (PS) is a chronic inflammatory skin disease, and it increasingly appears also in the elderly population. There is a rising interest in drug therapy for PS, especially for people receiving care in nursing homes (NH). Which PS-related drugs are prescribed in the time before nursing home admission (NHA), and to what extent does the supply of drugs change after NHA? Which specialties prescribe PS-related drugs? Statutory health insurance data were examined for people with PS, aged ≥ 65 years, who were newly admitted to a NH in the period 2011-2014 and observed for one year before and after NHA. Changes in prescription prevalence (pre-post comparison) were examined for significant differences. Prescriptions of PS-relevant drugs were measured by defined daily dose and stratified according to the prescribing specialist group. The analysis included 718 insured persons with PS (76.2% female, mean age 83.3 years). Systemic therapeutics played a minor role (pre: 2.6% vs. post: 2.1%) in drug therapy. Topical steroids had a high share of about 40% in the pre-post comparison. Overall, the proportion of people with PS who received treatment remained at a comparable level before and after NHA. A structured assessment of the skin is crucial, specifically in people with cognitive impairment.

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

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.

Uterotrophic and in vitro screening for (anti)estrogenic activity of dipyrone

Dipyrone is a commonly used analgesic in many countries and there is limited data on its possible endocrine disrupting effects. We performed a screening for in vivo and in vitro anti(estrogenic) activity of dipyrone. For the in vivo uterotrophic assay, immature female rats (22-days-old) were treated daily by oral gavage for three days with different doses of dipyrone alone (50, 100, 200 mg/kg/day) and associated with three ethynylestradiol (EE) doses (1, 3 and 10 μg/kg/day), which were based on a dose-response curve experiment. The uterine weight was used as a biomarker for estrogenicity. In a parallel in vitro approach, we used a yeast-based transcriptional activation reporter gene assay (Yeast Estrogen Screening - YES) for assessment of estrogenic agonistic and antagonistic effects of dipyrone and its main metabolites 4-methylaminoantipyrine (MAA) and 4-aminoantipyrine (AA). In the uterotrophic assay, animals that received EE at 1, 3 and 10 μg/kg/day showed an increase in relative uterine weight compared with vehicle-only rats (canola oil). Dipyrone did not increase uterine weight at any dose tested (50, 100 and 200 mg/kg/day) in relation to vehicle control, indicating absence of estrogenic activity. Furthermore, co-administration of dipyrone (50 and 200 mg/kg/day) and EE (1, 3 or 10 μg/kg/day) was unable to block EE estrogenic action in comparison to the groups treated with EE alone, indicating absence of antiestrogenic activity. In the YES assay dipyrone and its metabolites did not demonstrate estrogen agonistic or antagonistic properties in the yeast cells. These results suggest that dipyrone and its metabolites do not produce (anti)estrogenic effects in vivo or in vitro.

Efficacy of metamizole versus ibuprofen and a short educational intervention versus standard care in acute and subacute low back pain: a study protocol of a randomised, multicentre, factorial trial (EMISI trial)

INTRODUCTION

Low back pain (LBP) is among the top three most common diseases worldwide, resulting in a life with pain-related disability. To date, no study has assessed the efficacy of metamizole (dipyrone), a non-opioid analgesic and antipyretic prodrug compared with the conventional non-steroidal anti-inflammatory drug ibuprofen, in patients with an acute LBP episode. Further, it is unclear, whether a short educational intervention is superior to usual care alone.

OBJECTIVES

The objective of this study is to assess first, whether metamizole is non-inferior to ibuprofen in a new episode of acute or subacute LBP. Second, we aim to assess whether a short educational intervention including evidence-based patient information on the nature of LBP is superior to usual care alone.

METHODS AND ANALYSIS

An investigator-initiated multicentre, randomised, double blind trial using a factorial design will be performed. A total of 120 participants with a new episode of LBP will be recruited from GP practices, outpatient clinics and from emergency departments, and randomised into four different treatment groups: ibuprofen alone, ibuprofen and short intervention, metamizole alone, metamizole and short intervention. The primary endpoint for the medical treatment will be change in pain assessed on an 11-point Numeric Rating Scale after 14 days. The primary outcome for the short intervention will be change in the Core Outcome Measures Index assessed after 42 days.

ETHICS, DISSEMINATION AND FUNDING

This study has been approved by the responsible Ethics Board (Ethikkommission Bern/2018-01986) and the Swiss Agency for Therapeutic Products (Swissmedic/2019DR4002). Results will be published in open access policy peer-reviewed journals. The study is funded by the Swiss National Science Foundation (grant number 32 003B-179346).

TRIAL REGISTRATION NUMBER

NCT04111315.

Metamizole is a Moderate Cytochrome P450 Inducer Via the Constitutive Androstane Receptor and a Weak Inhibitor of CYP1A2

Metamizole is an analgesic and antipyretic drug used intensively in certain countries. Previous studies have shown that metamizole induces cytochrome (CYP) 2B6 and possibly CYP3A4. So far, it is unknown whether metamizole induces additional CYPs and by which mechanism. Therefore, we assessed the activity of 6 different CYPs in 12 healthy male subjects before and after treatment with 3 g of metamizole per day for 1 week using a phenotyping cocktail approach. In addition, we investigated whether metamizole induces CYPs by an interaction with the constitutive androstane receptor (CAR) or the pregnane X receptor (PXR) in HepaRG cells. In the clinical study, we confirmed a moderate induction of CYP2B6 (decrease in the efavirenz area under the plasma concentration time curve (AUC) by 79%) and 3A4 (decrease in the midazolam AUC by 68%) by metamizole. In addition, metamizole weakly induced CYP2C9 (decrease in the flurbiprofen AUC by 22%) and moderately CYP2C19 (decrease in the omeprazole AUC by 66%) but did not alter CYP2D6 activity. In addition, metamizole weakly inhibited CYP1A2 activity (1.79‐fold increase in the caffeine AUC). We confirmed these results in HepaRG cells, where 4‐MAA, the principal metabolite of metamizole, induced the mRNA expression of CYP2B6, 2C9, 2C19, and 3A4. In HepaRG cells with a stable knockout of PXR or CAR, we could demonstrate that CYP induction by 4‐MAA depends on CAR and not on PXR. In conclusion, metamizole is a broad CYP inducer by an interaction with CAR and an inhibitor of CYP1A2. Regarding the widespread use of metamizole, these findings are of substantial clinical relevance.

Metamizole but not ibuprofen reduces the plasma concentration of sertraline: Implications for the concurrent treatment of pain and depression/anxiety disorders

AIM

Comorbidity of pain and depression or anxiety is a challenging clinical phenomenon, often requiring the concurrent application of antidepressant and analgesic drugs. Growing evidence suggests that the analgesic metamizole exhibits cytochrome P450 inducing properties. In the present study, we assessed the impact of metamizole and ibuprofen on plasma concentrations of the selective serotonin reuptake inhibitor sertraline.

METHODS

Out of a therapeutic drug monitoring (TDM) database, three groups of patients were compared: patients receiving sertraline and metamizole (n = 15), patients receiving sertraline and ibuprofen (n = 19), and a matched control group without one of the analgesics (n = 19).

RESULTS

Metamizole was associated with 67% lower median sertraline plasma concentrations compared to the control group (14 vs 42 ng/mL, P < 0.001). In contrast, differences between the ibuprofen group and the control group did not reach statistical significance (31 vs 42 ng/mL, P = 0.128). Moreover, the metamizole group demonstrated lower dose-adjusted drug concentrations than the ibuprofen group (0.10 vs 0.26 (ng/mL)/(mg/day), P = 0.008). Finally, the metamizole group exhibited a higher proportion of patients whose sertraline concentrations were below the therapeutic reference range (40% in the metamizole group, 5% in the ibuprofen group, 0% in the control group, P = 0.005) indicating therapeutically insufficient drug concentrations.

CONCLUSION

Our findings support preliminary evidence that metamizole acts as a potent inductor of cytochrome P450 isoenzymes CYP2B6 and CYP3A4. We observed a clinically meaningful pharmacokinetic interaction between metamizole and sertraline, leading to insufficiently low sertraline drug concentrations. Clinicians should therefore consider alternative drug combinations or apply TDM-guided dose adjustment of sertraline.

Pain severity and analgesics use in the community-dwelling older population: a drug utilization study from Germany

Purpose

Chronic pain is common in the older population and a significant public health concern. However, comprehensive studies on analgesics use in this age group from Germany are scarce. This study aims to give a comprehensive overview on the use of the most common therapeutic groups of analgesics in community-dwelling older adults from Germany.

Methods

A cross-sectional study was carried out using data from a German cohort of 2038 community-dwelling adults aged 63–89 years. Descriptive statistics and logistic regression models were applied to assess the utilization of analgesics by age, sex, pain severity, pain duration, and locations.

Results

One out of four study participants was suffering from high-intensity or disabling pain. Approximately half of those taking analgesics still reported to suffer from high-intensity or disabling pain. Among analgesics users, occasional non-steroidal anti-inflammatory drugs (NSAIDs) use was the most frequent pain therapy (in 43.6% of users), followed by metamizole (dipyrone) use (16.1%), regular NSAIDs use (12.9%), strong opioids use (12.7%), and weak opioids use (12.0%). In multivariate logistic regression models, higher age, higher pain severity, longer pain duration, abdominal pain, and back pain were statistically significantly associated with opioids use. Metamizole use was also statistically significantly associated with higher pain severity but inversely associated with pain duration.

Conclusions

A significant number of older German adults are affected by high-intensity and disabling chronic pain despite receiving analgesics. Long-term studies are needed to compare the effectiveness and safety of different treatments for chronic pain in older adults.

Electronic supplementary material

The online version of this article (10.1007/s00228-020-02954-5) contains supplementary material, which is available to authorized users.

Regional Differences in Prescribing Patterns of Metamizole in Germany Based on Data from 70 Million Persons

The non-opioid analgesic metamizole (dipyrone) is commonly used in Germany despite its narrow indications and market withdrawal from several countries. In this study we analyzed prescribing patterns of metamizole focusing on regional differences. The source of data was the “Information system for health care data” which includes data from the statutory health insurance funds for about 70 million Germans. We received aggregated data of individuals with at least one metamizole prescription in 2010 as well as the number of prescribed packages by age, sex, state and district along with the number of insured persons in each stratum. We calculated prescription prevalence stratified by age, sex, state and district. Among 68.4 million insured persons (mean age: 43.6 years; 53.0% female) 5.5 million received at least one metamizole prescription (8.1%, overall 12.2 million packages). Prevalence increased with age, and women received metamizole more often than men. In adults (total prevalence: 9.4%), levels varied between 7.0% (Saxony) and 11.1% (Schleswig-Holstein), whereas on a district level use ranged from 4.3% to 14.3%. In 2010, one of 12 individuals received metamizole at least once. Noticeable were the large regional variations which certainly cannot be explained by patient-related factors.

Agranulocytosis attributed to metamizole: An analysis of spontaneous reports in EudraVigilance 1985-2017

Despite ongoing debates about its safety, the use of metamizole (dipyrone) is still increasing in many countries. In this study, we analysed spontaneous reports of suspected metamizole-associated agranulocytosis recorded in EudraVigilance database from 1985 to 2017 with regard to patient and treatment characteristics as well as fatal vs non-fatal outcomes and compared these findings among countries. A total of 1448 reports from 31 different countries were included (Germany 42.0%; Spain 29.6%; Switzerland 13.1%; other countries 15.3%). Mean age of patients was 53.6 years (63.4% females). Differences among countries were observed, for example with respect to patient age, route of administration and daily doses. Overall, median time between starting metamizole and developing an agranulocytosis was 13 days with 34.7% of cases occurring up to 7 days. This time was much shorter in patients who had already received metamizole before (median: 6 vs 15 days). About 16% of cases ended fatally. Patients with fatal outcomes were older and more often had also received methotrexate compared to those with non-fatal outcomes. When adjusting for age and sex in a multivariable logistic regression, methotrexate was associated with an increased risk of fatal outcomes (odds ratio: 5.18; 95% confidence interval: 3.06-8.78). In conclusion, metamizole-associated agranulocytosis is still a life-threatening condition, especially in the elderly and those also receiving methotrexate. As agranulocytosis can develop weeks after last administration and independently of dose and duration of treatment, prescribers and patients should be aware of its signs and symptoms.

Prevalence and treatment of hip and knee osteoarthritis in people aged 60 years or older in Germany: an analysis based on health insurance claims data

Objective

Osteoarthritis (OA) is highly prevalent throughout the world, especially in the elderly population, and is strongly associated with patients’ frailty. However, little is known about the prevalence and treatment of OA in elderly patients in routine clinical care in Germany.

Materials and methods

As a part of Linking Patient-Reported Outcomes with CLAIms Data for Health Services Research in Rheumatology (PROCLAIR), a cross-sectional study using claims data from a large Germany statutory health insurance (BARMER) was conducted. We included people aged 60 years or older and assessed the prevalence of OA of the hip or knee, defined as having outpatient diagnoses (ICD: M16 or M17) in at least two quarters of 2014. The use of conservative treatment, including analgesics and physical therapy, and total joint replacement was studied. Analyses were stratified by age, sex, comorbidities, and level of care dependency defined by social law.

Results

A total of 595,754 patients (mean age: 74.9 years; 69.8% female) were diagnosed with OA (21.8%), with the highest prevalence in those between 80 and 89 years (31.0%) and in females compared to males (23.9% vs 18.3%). Prevalence decreased with increasing level of care dependency from 30.5% in patients with a low level (0/1) to 18.7% in the highest level of care dependency. A total of 63.4% of the patients with OA received analgesics, with higher use with increasing age. Physical therapy was prescribed to 43.1% of the patients, but use decreased with age. In all, 5.3% of the patients received total joint replacement in 2014.

Conclusion

The lower frequency of coded OA with increasing level of care dependency may reflect underdiagnosis, and patients with many other medical problems seem to be at risk for inadequate recognition and treatment of their OA.

[Dipyrone (metamizole) : Considerations on monitoring for early detection of agranulocytosis]

BACKGROUND

Dipyrone (metamizole) is a non-opioid analgesic commonly used in Germany, which can, in very rare cases, cause life-threatening agranulocytosis. The prescribing information calls for regular monitoring of the differential blood count in cases of long-term treatment. However, there is uncertainty about how this testing should be handled in practice.

OBJECTIVES

Which recommendations can be derived from the published literature for evaluating blood cell counts during treatment with metamizole and which other options for monitoring exist?

METHODS

Data from recent epidemiological studies, reviews, and spontaneously reported cases were evaluated.

RESULTS

Agranulocytosis can emerge at highly variable intervals ranging from the first day of metamizole treatment to months after treatment has begun. As a result, there is no conclusive, evidence-based recommendation for the time intervals at which blood cell counts should be tested. Therefore, the onset of clinical symptoms should be used as trigger for monitoring blood cell counts to enable early diagnosis and avoid agranulocytosis-related complications. In addition to general symptoms like fever, sore throat, fatigue, and muscle pain, mucosal ulcerations, severe angina, and systemic infections leading to sepsis are typical of agranulocytosis.

CONCLUSIONS

Providing patients and medical staff with better information about early symptoms of agranulocytosis could be a sensible way to prevent complications. Any suspicion of agranulocytosis should immediately lead to a differential blood count and to the withdrawal of all drugs possibly associated with agranulocytosis. Patients should be monitored and treated according to the severity of their symptoms.

Post-marketing drug withdrawals: Pharmacovigilance success, regulatory problems

Modern pharmacovigilance began in the 1960s, since when the subject has grown markedly, interest having particularly increased since 2010. One index of its success is the increasing speed with which serious adverse drug reactions are discovered after marketing of a medicinal product. However, the speed with which products have subsequently been withdrawn as a result of the discovery of serious adverse reactions has not consistently changed. This highlights problems that regulators and manufacturers face when serious reactions are discovered, with difficulties in deciding which of several consequent actions to take: to add specific warnings (cautions) or contraindications to the product label; to issue a Direct Healthcare Professional Communication; to allow informed patients to decide whether they will take the drug; or, in the most serious cases, to withdraw the product or revoke the licence. Conflicts of interest may inhibit decision-making. Recommendations that arise from these observations are that: health professionals and patients should be more vigorously encouraged to report suspected adverse drug reactions; regulatory authorities and drug manufacturers should take quicker confirmatory action when serious suspected adverse drug reactions are reported, even anecdotally, with formal studies to test for causality conducted sooner rather than later, applying lower than usual thresholds for suspicion; temporary suspensions or restrictions could be considered during such assessments; universal guidelines are needed for determining when a drug should be withdrawn if serious adverse drug reactions are suspected; there should be more rigorous monitoring and verification of deaths and reporting of reasons for drop-outs during clinical trials, with more transparency in reporting adverse events and ready access to premarketing clinical study reports; post-marketing drug monitoring systems and medicines regulation in low-to-middle income economies, especially in Africa, where withdrawals are fewer than elsewhere, should be strengthened.

Changes over time in prescription practices of pain medications in Switzerland between 2006 and 2013: an analysis of insurance claims

BACKGROUND

In Europe, scant information is available about prescription practices for pain medications. The aim of this research was to assess changes in prescription rates of non-opioid, weak opioid, and strong opioid medications between 2006 and 2013 in the Swiss population.

METHODS

Using insurance claims data covering one-sixth of the Swiss population, we analyzed the numbers of reimbursed pain medications, the number of reimbursements per persons, and the cumulative dose in milligrams. For opioids, the morphine equivalent dose and treatment days were calculated. Data were extrapolated to the dose per day per 100'000 population stratified by age, gender, and canton.

RESULTS

In total, 4'746'942 paracetamol, 2'156'620 NSAIDs or Coxibs, 931'129 metamizole, 1'322'272 weak opioid, and 807'835 strong opioid claims were analyzed. Between 2006 and 2013, the increase in claims per 100'000 persons was 32% for paracetamol, 242% for metamizole, 107% for NSAIDS, 86% for Coxibs, 13% for weak opioids, and 121% for strong opioids. For strong opioids the total MED in mg /100'000 increased by 117%, the treatment days /100'000 by 101%. For strong opioids, fentanyl was most frequently used (increase between 2006 and 2013 by 91% for MED/100'000 persons and 94% treatment days / 100'000) followed by buprenorphine and oxycodone. The highest proportional increase in MED / 100'000 was observed for methadone (+1414%) and oxycodone (+313%). Marked geographical variation was detected in the use of metamizole, paracetamole, and strong opioids in different cantons.

CONCLUSION

The analysis of insurance claims data provides evidence that the prescription rates for pain medications increased in Switzerland within the last ten years, in particular for metamizole and strong opioids. Furthermore, the prescription rates for metamizole, paracetamol, and strong opioids varied substantially between different cantons in Switzerland.

Metamizole/dipyrone for the relief of cancer pain: A systematic review and evidence-based recommendations for clinical practice

BACKGROUND

Dipyrone (metamizole) is one of the most widely used non-opioid analgesics for the treatment of cancer pain.

AIM

Because evidence-based recommendations are not yet available, a systematic review was conducted for the German Guideline Program in Oncology to provide recommendations for the use of dipyrone in cancer pain.

DESIGN

First, a systematic review for clinical trials assessing dipyrone in adult patients with cancer pain was conducted. Endpoints were pain intensity, opioid-sparing effects, safety, and quality of life.

DATA SOURCES

The search was performed in MedLine, Embase (via Ovid), and the Cochrane Library (1948-2013) and additional hand search was conducted. Finally, recommendations were developed and agreed in a formal structured consensus process by 53 representatives of scientific medical societies and 49 experts.

RESULTS

Of 177 retrieved studies, 4 could be included (3 randomized controlled trials and 1 cohort study, n = 252 patients): dipyrone significantly decreased pain intensity compared to placebo, even if low doses (1.5-2 g/day) were used. Higher doses (3 × 2 g/day) were more effective than low doses (3 × 1 g/day), but equally effective as 60 mg oral morphine/day. Pain reduction of dipyrone and non-steroidal anti-inflammatory drugs did not differ significantly. Compared to placebo, non-steroidal anti-inflammatory drugs, and morphine, the incidence of adverse effects was not increased.

CONCLUSION

Dipyrone can be recommended for the treatment of cancer pain as an alternative to other non-opioids either alone or in combination with opioids. It can be preferred over non-steroidal anti-inflammatory drugs due to the presumably favorable side effect profile in long-term use, but comparative studies are not available for long-term use.

Analgesic prescribing in care home residents: how epidemiological studies may inform clinical practice

Care home residents are often frail with multiple comorbidities and cognitive impairment, most commonly caused by dementia. This population is under-represented in clinical trials, leading to a lack of valid and reliable evidence to inform clinicians' prescribing practice. This paper summarizes how epidemiological research conducted in similar populations can inform pain management by describing pain prevalence, risk factors, typical features and functional consequences. This evidence can help overcome the numerous barriers to optimal pain management in care home residents.

Pain medication in German nursing homes: a whole lot of metamizole

PURPOSE

Prescribing of metamizole (dipyrone), an analgesic that has been withdrawn from the market or never approved in many countries owing to safety concerns, is high in elder persons in Germany. This study assessed the use of pain medications in German nursing homes with a special focus on prescribing patterns of metamizole.

METHODS

Using data of the 'Inappropriate Medication in Patients with Renal Insufficiency in Nursing Homes' (IMREN) study conducted between October 2014 and April 2015 in nursing homes in Bremen and Lower Saxony, we studied prescribing of analgesics including both scheduled and as-needed medications. For residents with scheduled medication, dosage and duration of use were analysed.

RESULTS

A total of 852 residents from 21 nursing homes were included. They were on average 83.5 years old, and 76.5% were women; 73.8% received at least one analgesic with 70.3% obtaining World Health Organization step I drugs. The most frequently prescribed substances were metamizole (for 40.6%) and paracetamol (acetaminophen; 35.6%), with paracetamol given mostly as-needed. The proportion of residents receiving metamizole increased with age (up to 47.4% in persons aged 90 years and over). Of 143 residents with scheduled metamizole (16.8%), the mean daily dosage was 1843 mg (interquartile range [IQR]: 1500-2250); 66.9% received metamizole for at least 90 days and 23.2% for at least 365 days (mean duration 276 days; IQR: 59-314).

DISCUSSION

There is a discrepancy between prescribing of metamizole for older persons, on the one hand, and evidence on comparative effectiveness and safety as well as approval and recommendations, on the other hand. Copyright © 2016 John Wiley & Sons, Ltd.