Metamizole-induced agranulocytosis revisited: results from the prospective Berlin Case-Control Surveillance Study

A novel synthetic oxazolidinone derivative BS-153 attenuated LPS-induced inflammation via inhibiting NF-κB/pkcθ signaling pathway

BS-153, a new derivative of oxazolidinone, was firstly found having potent anti-inflammatory effects both in vitro and in vivo. Our study aimed to study its potential molecular mechanisms. Firstly, BS-153 significantly inhibited the expression levels of inflammatory mediators (iNOS and COX-2) and pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) on LPS-stimulated RAW264.7 cells in a dose-dependent manner. Subsequently, NF-κB nuclear translocation was blocked by 10 nM BS-153 after LPS-activated, and the phosphorylation of IκB, which could bind NF-κB and limit NF-κB nuclear translocation, was notably downregulated. The mechanistic investigation was followed the NF-κB-ikkα-TLR4/PKCθ pathway. The kinase panel screen and WB result revealed that BS-153 inhibited PKCθ phosphorylation on thr538 and ser643/676 site, and the expression of IL-17ɑ, instead of TLR4/myd88. Similarly in vivo anti-inflammatory activity was assessed by LPS-stimulation and tail-amputation in zebrafish and the results indicated that macrophages migration and infiltration were significantly inhibited by BS-153. In addition, RT-PCR results discovered that BS-153 can reduce the level of TNF-α, IL-1b and COX-2. In summary, we established BS-153 and evaluated anti-inflammatory effect for the first time. The mechanism analysis showed that BS-153 possesses anti-inflammatory activities by inhibiting the phosphorylation of PKCθ, and then leading to the inactivation of NF-κB pathway. These findings implied that BS-153 is a potential candidate for the treatment of inflammatory-related diseases.

A brief overview of chikungunya-related pain

Pain is an important symptom associated with the arboviral disease caused by the Chikungunya virus (CHIKV). For a significant number of patients, this symptom can persist for months or even years, negatively affecting their quality of life. Unfortunately, pharmacological options for this condition are limited and only partially effective, as the underlying mechanisms associated with CHIKV-induced pain are still poorly understood. The re-emergence of CHIKV has led to new outbreaks, and the expected high prevalence of pain in these global events requires new scientific advances to find more effective solutions. Here we review the main aspects of pain caused by CHIKV infection, such as the anatomy of the affected sites, the prevalence and management of this symptom, the diversity of possible cellular and molecular mechanisms, and finally highlight a promising meningeal pathway to elucidate the mechanisms involved in the unsolved problem of CHIKV-associated pain.

Methotrexate - Safe Backbone for the Treatment of Rheumatoid Arthritis

Methotrexate (MTX) is the primarily used disease-modifying antirheumatic drug (DMARD) for the treatment of Rheumatoid Arthritis (RA). MTX is a safe agent, even when used for years - provided that treatment is regularly monitored and prescribers follow some simple rules, such as prescribing tablets of a single strength only. Proper patient education contributes greatly to safe treatment. The knowledge of important pharmacologic facts, possible interactions, and clinical warning signs also helps to prevent or recognize intoxications early. Therefore, this review addresses key aspects regarding the safety of MTX. In this respect, it includes adverse events, possible interactions with frequently used drugs and details on the rare but life-threatening intoxication, e.g., due to erroneous daily intake.

Impact of analgesic regimen on patient outcome following subarachnoid hemorrhage: positive adjuvant effects of metamizole

INTRODUCTION

Various analgesics are used to control intense headaches in patients following subarachnoid hemorrhage. In addition to pain control, it has been shown that some analgesics can affect various pathophysiological cascades. Therefore, we devised a study to assess whether the use of metamizole has a significant impact on the development of ischemic complications, hydrocephalus, and the overall outcome in patients following aneurysmal subarachnoid hemorrhage in the context of the other non-opioids and opioids effects.

METHODS

In our retrospective, single-center cohort study, we enrolled 192 patients diagnosed with subarachnoid hemorrhage. We recorded their initial clinical status, comorbidities, and the daily dosage of analgesics over 14 days of hospitalization after the onset of subarachnoid hemorrhage. Using univariate and subsequent multivariate logistic regression analysis, we assessed the influence of various factors, including analgesics, on the development of delayed cerebral ischemia and hydrocephalus, as well as on 2-week and 6-month outcomes.

RESULTS

Although the administration of non-opioids, in general, had no effect on the development of delayed cerebral ischemia or hydrocephalus, the use of metamizole as the main analgesic was associated with a significantly lower chance of poor outcome at both 2-weeks and 6-months, as well as the development of delayed cerebral ischemia. As opioids were indicated primarily for analgosedation in mechanically ventilated patients with poor clinical status, their usage was associated with a significantly higher chance of poor outcome, delayed cerebral ischemia, and hydrocephalus.

CONCLUSION

Our results suggest that the prescription of metamizole may be associated with better outcomes and a lower chance of delayed cerebral ischemia development in patients after subarachnoid hemorrhage. Considering the retrospective nature of our study and the limited worldwide availability of metamizole due to its prohibition in some countries, our results do not demonstrate a clear benefit but rather justify the need for subsequent prospective studies.

Prescribing pattern insights from a longitudinal study of older adult inpatients with polypharmacy and chronic non-cancer pain

BACKGROUND

The present study sought to determine the prevalence of chronic non-cancer pain (CNCP) among older adult inpatients with polypharmacy. It also aimed to analyse prescription patterns and assess the therapy adequacy and patient complexity for those with and without CNCP.

METHODS

This 4-year longitudinal study examined data from an exhaustive acute care hospital register on home-dwelling older adult patients (≥65) with polypharmacy. Commonly known combinations of potentially inappropriate medications were used to estimate therapy adequacy. Patient complexity was evaluated by comparing number of comorbidities and investigating physical and cognitive deficits.

RESULTS

We determined a prevalence of CNCP of 9.7% among all older adult inpatients with polypharmacy, rising to 11.3% for those aged ≥85. Overall, CNCP patients were prescribed more drugs and had more comorbidities and physical and cognitive deficits than patients without CNCP. Older adult patients with CNCP received more analgesics, greater quantities of opioids, paracetamol and co-analgesics and elevated opioid dosages. Older adult patients with CNCP aged ≥85 received fewer analgesics, opioids, non-steroidal anti-inflammatory drugs and co-analgesics but more paracetamol. Older adult patients with CNCP were prescribed more potentially inappropriate medications involving opioids. In particular, 24.5% received an opioid and a hypnotic (benzodiazepine or Z-drug), and 8.6% received an opioid and a gabapentinoid.

CONCLUSION

Observed differences in medication use between older adult inpatients with or without CNCP may be relevant for clinical practice. Potentially inadequate co-prescribing (such as hypnotics and opioids) affects a higher proportion of patients with CNCP and may have serious unintended consequences.

SIGNIFICANCE STATEMENT

This study describes differences in prescription patterns between people with and without chronic non-cancer pain in a large dataset of 20,422 discharges. The differences found may be relevant to clinical practice. In particular, high co-prescribing of opioids and hypnotics may have serious unintended consequences. Greater physical and cognitive deficits may indicate greater patient complexity, and appropriate interventions need to be developed to improve the management of this vulnerable patient group.

Risk of agranulocytosis with metamizole in comparison with alternative medications based on health records in Spain

PURPOSE

We aimed to estimate the absolute (incidence) and relative (hazard ratio; HR) risk of agranulocytosis associated with metamizole in comparison with non-steroidal antiinflammatory drugs (NSAIDs).

METHODS

A cohort study of new users of metamizole versus NSAIDs was performed with BIFAP (Pharmacoepidemiologic Research Database in Public Health Systems; Spain). Patients aged ≥ 2 years in 2005-2022 were followed up from the day after their first metamizole or NSAID dispensation till the end of the treatment period to identify patients hospitalized due to idiosyncratic agranulocytosis. Incidence rate (IR) and adjusted HR of agranulocytosis with metamizole versus NSAID were estimated assuming the onset date of agranulocytosis was the date of hospitalization sensitivity analysis or 7 days before (main analysis). In secondary analyses, we used (1) opioids-paracetamol as negative control and (2) any hospitalized neutropenia as outcome (assuming the onset was 7 days before).

RESULTS

The cohorts included 444,972 new users of metamizole, 3,814,367 NSAID, and 3,129,221 opioids-paracetamol on continuous treatment during a median of 37-40 days. Overall, 26 hospitalized agranulocytosis occurred, 5 in the first week (and so removed in main analysis) and 21 thereafter. IR of agranulocytosis was 14.20 (N = 5 cases) and 8.52 (N = 3), 1.95 (N = 6) and 1.62 (N = 5), and 4.29 (N = 15) and 3.72 (N = 13)/107 person-weeks of continuous treatment using the date of hospitalization or 7 days before, respectively. Two, 0 and 2 of cases identified in both analyses had neoplasia in every cohort, respectively. HR of agranulocytosis associated with metamizole was 7.20 [95% CI: 1.92-26.99] and 4.40 [0.90-21.57] versus NSAID, and 3.31 [1.17-9.34] and 2.45 [0.68-8.83] versus opioid-paracetamol, respectively. HR of neutropenia with metamizole was 2.98 [1.57-5.65] versus NSAID.

CONCLUSIONS

Agranulocytosis was very rare but more common (above 4 times more) with metamizole than other analgesics. The impact of the drug-induced agranulocytosis was less precise with metamizole than the comparators due to its lower use, which precluded to find statistical differences in main analysis. The increased risk of hospitalized neutropenias with metamizole supports the link with its severity although triggers unavailable during the follow-up (ex. cytotoxic medication) can not be discarded.

Isolated Severe Neutropenia in Adults, Evaluation of Underlying Causes and Outcomes, Real-World Data Collected over a 5-Year Period in a Tertiary Referral Hospital

Background and Objectives: In clinical practice, neutropenia is frequently accompanied by other cytopenia; isolated non-chemotherapy-induced severe neutropenia is less frequent and its differential diagnosis can be challenging. In this real-world study with data collected over a 5-year period in a tertiary referral hospital, we primarily sought to identify underlying causes of isolated severe neutropenia (<0.5 × 109/L). Secondly, we aimed to analyze its management and outcomes. Materials and Methods: From 444,926 screened patients, after exclusion of patients with chemotherapy, radiotherapy, hematological neoplasms, additional cytopenia, and benign ethnic neutropenia, we identified and analyzed data from 70 patients (0.015%) with isolated severe neutropenia. We thus confirmed that the occurrence of isolated severe neutropenia is a rare event, even in a tertiary hospital. Results: The median age at diagnosis was 34 years (range 1-81) and 65% were female. Acute neutropenia was more frequently observed (n = 46/70, 65.7%); the main underlying causes in this group were drugs (n = 36/46, 78%) followed by infections (n = 10/46, 21.7%). We identified 24 (34.3%) patients with chronic neutropenia. The majority of them (n = 12/24, 50%) had an idiopathic form (CIN), 8/24 (33%) were autoimmune (AIN), and 4/24 (17%) were congenital. Conclusions: This study demonstrates the rarity and heterogeneity of isolated severe neutropenia and the steps to consider in its diagnostic work-up and management. Epidemiological characteristics, diagnostic work-up, and management including hospitalizations are described. Due to the high frequency of metamizole-induced neutropenia observed in this study, we want to raise awareness about its use, since this complication generates frequent hospitalizations even in young, otherwise healthy patients. Furthermore, recurrent infections in chronic forms of idiopathic neutropenia were quite common, suggesting a difference in phenotypes and need for therapy consideration depending on the clinical course.

Use of metamizole and other non-opioid analgesics in Switzerland between 2014 and 2019: an observational study using a large health insurance claims database

OBJECTIVE

To investigate claims patterns for metamizole and other non-opioid analgesics in Switzerland. To characterise users of these non-opioid analgesics regarding sex, age, comedications and canton of residence.

METHODS

We conducted a retrospective descriptive study using administrative claims data of outpatient prescribed non-opioid analgesics of the Swiss health insurance company Helsana between January 2014 and December 2019. First, we evaluated the number of claims and defined daily doses  per year of metamizole, ibuprofen, diclofenac and paracetamol in adults aged 18 years or over. Second, we characterised new users of these non-opioid analgesics in terms of sex, age, claimed comedications and canton of residence.

RESULTS

From 2014 to 2019, among the investigated non-opioid analgesics, metamizole showed the highest increase in claims (+9545 claims, +50%) and defined daily doses (+86,869 defined daily doses, +84%) per 100,000 adults. Metamizole users had the highest median age (62 years [IQR: 44-77]) compared to ibuprofen (47 years [IQR: 33-62]), diclofenac (57 years [IQR: 43-71]) and paracetamol (58 years [IQR: 39-75]) users. Metamizole users also more frequently claimed proton pump inhibitors, anticoagulants, platelet aggregation inhibitors and antihypertensive drugs than users of other non-opioid analgesics. While metamizole was most frequently claimed in German-speaking regions of Switzerland, ibuprofen and paracetamol were most frequently claimed in the French-speaking regions and diclofenac in German- and Italian-speaking regions.

CONCLUSION

In Switzerland, metamizole was increasingly claimed between 2014 and 2019. Metamizole was most frequently claimed by older adults and patients with comedications suggestive of underlying conditions, which can be worsened or caused by use of nonsteroidal anti-inflammatory drugs. The lack of studies regarding the effectiveness and safety of metamizole in this population warrants further investigation.

Case Report: Simultaneously Induced Neutropenia and Hemolysis After a Single Metamizole Dose

BACKGROUND AND OBJECTIVE

Metamizole is a non-opioid ampyrone sulfonate compound with potent analgesic, antipyretic, and spasmolytic effects. Agranulocytosis is a rare life-threatening complication of metamizole.

CASE

Here, we present the case of a 62-year-old patient who developed agranulocytosis as well as hemolysis after a single administration of metamizole.

CONCLUSION

This case illustrates the inherent allergic potential of metamizole and its effects on different hematopoietic cell types.

Additive or synergistic analgesic effect of metamizole on standard pain treatment at home after arthroscopic shoulder surgery: A randomised controlled superiority trial

BACKGROUND

There is growing evidence that the analgesic effect of metamizole is mediated at least partly by central mechanisms, including the endocannabinoid/endovanilloid system. Consequently, metamizole may have additive or even synergistic analgesic effects with paracetamol and nonsteroidal anti-inflammatory drugs (NSAID).

OBJECTIVE

This study aimed to assess if triple therapy with metamizole, ibuprofen and paracetamol (MIP) is superior to double therapy with ibuprofen and paracetamol (i.p.) in treating pain at home after ambulatory arthroscopic shoulder surgery.

DESIGN/SETTING/PATIENTS/INTERVENTION

In this double-blind, controlled, high-volume single centre, superiority trial, 110 patients undergoing elective ambulatory arthroscopic shoulder surgery were randomised to receive either MIP ( n  = 55) or i.p. ( n  = 55) orally for 4 days between December 2019 and November 2021. Pain intensity at movement and rest, using a numeric rating scale (NRS), perceived pain relief, use of rescue medication and adverse effects of study medication were recorded at the post-anaesthesia care unit (PACU) and on postoperative day (POD) 1 to 4 and 7. Quality of Recovery (QoR) and satisfaction with study medication were measured at POD 7 with telephone follow-up.

MAIN OUTCOME MEASURE

The primary outcome measure was postoperative pain intensity on movement measured by an 11-point NRS (where 0 = no pain and 10 = worst pain imaginable) on POD 1.

RESULTS

For the primary outcome, superiority of MIP in reducing postoperative pain at movement on POD 1 was not confirmed: mean difference NRS [95% confidence interval (CI), -0.08 (-1.00 to 0.84)]. For pain on movement and at rest, no significant differences were found between groups in the PACU nor on POD 1 to 4 or day 7. Nausea was reported significantly more frequently in the metamizole group (22.6 vs. 58.5; P  < 0.001). Other adverse effects of study medication, rescue opioid consumption, perceived pain relief, QoR at POD 7, and overall patient satisfaction were similar in both groups.

CONCLUSION

Clinically, triple oral treatment with metamizole, paracetamol and ibuprofen is not superior to oral paracetamol and ibuprofen in multimodal pain treatment at home after ambulatory arthroscopic shoulder surgery.

TRIAL REGISTRATION

European Union Clinical Trials Register 2019-002801-23 and Clinicaltrials.gov NCT04082728.

A Case Report on Metamizole-Induced Agranulocytosis: Is the Benefit Worth the Risk?

Metamizole is a drug with analgesic and antipyretic properties widely available in Portugal. Its use is highly controversial because of the risk of agranulocytosis, a rare but serious adverse event. A 70-year-old female patient with a recent history of treatment with metamizole for post-surgery fever and pain presented to the ED with sustained fever, diarrhea, and painful mouth ulcers. Laboratory tests revealed agranulocytosis. The patient was placed under protective isolation and started treatment with granulocyte-colony stimulating factor (G-CSF) and empiric antibiotic therapy with piperacillin/tazobactam and vancomycin for neutropenic fever. After an extensive workup, no source of infection was identified. During hospitalization, infectious and neoplastic causes of agranulocytosis were investigated, but the results were negative. Metamizole-induced agranulocytosis was suspected. The patient completed a total of three days of G-CSF and eight days of empiric antibiotic therapy with sustained clinical improvement. She was discharged completely asymptomatic and remained clinically stable during follow-up without a resurgence of agranulocytosis. This case report is intended to increase awareness of metamizole-induced agranulocytosis. While this is a well-known side effect, it is also often overlooked. It is paramount that both physicians and patients know how to correctly manage metamizole to prevent and promptly treat agranulocytosis.

Self-Medication in Rural Northeastern Romania: Patients' Attitudes and Habits

In recent years, many healthcare systems, along with healthcare professionals, have provided services in a patient-centered manner, in which patients are key actors in the care process. Encouraging self-care creates responsible patients, but it must be practiced responsibly. This study aims to analyze the tendency towards self-medication for patients from a rural area in Northeastern Romania. Data were collected using a questionnaire, which consisted of 25 questions, that has been developed by the research team. Student's T test or one-way ANOVA was used, and the reliability of the questionnaire was calculated using Cronbach's alpha coefficient. Fifty-eight patients agreed to participate and were interviewed. The results of the study suggest that respondents practice self-medication, which they resort to when their condition cannot be treated with natural remedies or herbs and when it impairs their ability to do their daily activities. Self-medication could be explained by the lack of self-care services as well as the trust patients have in the specific treatment. Patients prefer asking the pharmacist for drugs instead of visiting a physician, which could be due to higher accessibility and time-efficiency, while also being prone to stock up on certain medications due to limited access to healthcare.

Liver Transplantation and the Use of Metamizole to Treat Drug-induced Liver Injury

Metamizole, or dipyrone, is a frequently prescribed analgetic drug that can cause drug-induced liver injury (DILI). Still, there are only a few metamizole-associated DILI cases (n = 61, including our study) described in the literature. So far liver transplantation has been reported in 6 patients with metamizole-induced acute liver failure. In 2020, a German group described a bigger cohort (n = 23) of metamizole-related DILI. Shortly thereafter, this issue gained wider attention as the German Federal Institute for Drugs and Medical Devices published a Direct Healthcare Professional Communication, emphasizing DILI as a potential adverse event caused by metamizole. We herein report 2 patients that were admitted to our liver transplant center due to acute liver failure (ALF) in April and May 2021. Both patients reported intake of metamizole as pain medication over a few weeks. After ruling out alternative reasons for ALF and fulfilling the King's College criteria both patients received emergency liver transplantations in our center. Pathology assessment of both explants were consistent with metamizole-associated DILI. As illustrated by our 2 cases of metamizole-induced liver failure with subsequent liver transplantation, this rare but presumably often overlooked adverse drug effect of metamizole should be considered as differential diagnosis in cases of cryptogenic liver failure.

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.

Cytochrome P450 1A2 is the most important enzyme for hepatic metabolism of the metamizole metabolite 4-methylaminoantipyrine

Aims

Metamizole (dipyrone) is a prodrug not detectable in serum or urine after oral ingestion. The primary metabolite, 4‐methylaminoantipyrine (4‐MAA), can be N‐demethylated to 4‐aminoantipyrine (4‐AA) or oxidized to 4‐formylaminoantipyrine (4‐FAA) by cytochrome P450 (CYP)‐dependent reactions. We aimed to identify the CYPs involved in 4‐MAA metabolism and to quantify the effect of CYP inhibition on 4‐MAA metabolism.

Methods

We investigated the metabolism of 4‐MAA in vitro using CYP expressing supersomes and the pharmacokinetics of metamizole in the presence of CYP inhibitors in male subjects.

Results

The experiments in supersomes revealed CYP1A2 as the major CYP for 4‐MAA N‐demethylation and 4‐FAA formation with CYP2C19 and CYP2D6 contributing to N‐demethylation. In the clinical study, we investigated the influence of ciprofloxacin (CYP1A2 inhibitor), fluconazole (CYP2C19 inhibitor) and the combination ciprofloxacin/fluconazole on the pharmacokinetics of metamizole in n = 12 male subjects in a randomized, placebo‐controlled, double‐blind study. The geometric mean ratios for the area under the concentration–time curve of 4‐MAA after/before treatment were 1.17 (90% CI 1.09–1.25) for fluconazole, 1.51 (90% CI 1.42–1.60) for ciprofloxacin and 1.92 (90% CI 1.81–2.03) for ciprofloxacin/fluconazole. Fluconazole increased the half‐life of 4‐MAA from 3.22 hours by 0.47 hours (95% CI 0.13–0.81, P < .05), ciprofloxacin by 0.69 hours (95% CI 0.44–0.94, P < .001) and fluconazole/ciprofloxacin by 2.85 hours (95% CI 2.48–3.22, P < .001).

Conclusion

CYP1A2 is the major CYP for the conversion of 4‐MAA to 4‐AA and 4‐FAA. The increase in 4‐MAA exposure by the inhibition of CYP1A2 and by the combination CYP1A2/CYP2C19 may be relevant for dose‐dependent adverse reactions of 4‐MAA.

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.

Drug-Induced Idiosyncratic Agranulocytosis - Infrequent but Dangerous

Drug-induced agranulocytosis is a life-threatening side effect that usually manifests as a severe form of neutropenia associated with fever or signs of sepsis. It can occur as a problem in the context of therapy with a wide variety of drug classes. Numerous drugs are capable of triggering the rare idiosyncratic form of agranulocytosis, which, unlike agranulocytosis induced by cytotoxic drugs in cancer chemotherapy, is characterised by “bizzare” type B or hypersensitivity reactions, poor predictability and a mainly low incidence. The idiosyncratic reactions are thought to be initiated by chemically reactive drugs or reactive metabolites that react with proteins and may subsequently elicit an immune response, particularly directed against neutrophils and their precursors. Cells or organs that exhibit specific metabolic and biotransformation activity are therefore frequently affected. In this review, we provide an update on the understanding of drug-induced idiosyncratic agranulocytosis. Using important triggering drugs as examples, we will summarise and discuss the chemical, the biotransformation-related, the mechanistic and the therapeutic basis of this clinically relevant and undesirable side effect.

Risikostratifizierung in der Rheumatologie: Analgetika-Therapie

Auch im Biologika-Zeitalter ist Schmerz ein häufiges Symptom bei Patienten mit rheumatischen Erkrankungen. NSAR sind dabei unverändert meist Mittel der ersten Wahl. Insbesondere aufgrund ihres gastrointestinalen, kardiovaskulären und renalen Nebenwirkungspotenzials erfordert ihr Einsatz eine individuelle Risikostratifizierung beim Patienten in Abhänggigkeit von der zugrundeliegenden Erkrankung, den Komorbiditäten und der Komedikation.

Bei NSAR-Versagen oder -Unverträglichkeit stehen nur wenige Nichtopioid-Analgetika als Alternative zur Verfügung. Paracetamol ist häufig nicht ausreichend effektiv und bedarf eines hepatischen Monitorings. Beim Einsatz von Metamizol ist bei meist guter Wirksamkeit und allgemein guter Verträglichkeit über die sehr seltene Möglichkeit einer Agranulozytose und deren Symptome aufzuklären. Sofern auch hiermit keine zufriedenstellende Schmerzkontrolle möglich ist, können Opioide zum Einsatz kommen. Die Risikostratifizierung erfordert hier ein leitliniengerechtes Abwägen des zu erwartenden Nutzens in Abhängigkeit von der Grunderkrankung einerseits und den Risiken andererseits, wobei v. a. psychische Effekte einschl. Missbrauchs- und Abhängigkeitspotenzial, Übelkeit, Obstipation und erhöhtes Sturzrisiko im Fokus stehen.

Für die nahe Zukunft sind keine wesentlichen Neuentwicklungen bei den Analgetika zu erwarten, sodass die individuelle Risikostratifizierung für die derzeit verfügbaren Präparate langfristig entscheidend für eine optimale Therapie des einzelnen Patienten bleiben wird.

Dipyrone as pre-emptive measure in postoperative analgesia after tonsillectomy in children: a systematic review

INTRODUCTION

Tonsillectomy is the 2nd most common outpatient surgery performed on children in the United States of America. Its main complication is pain, which varies in intensity from moderate to severe. Dipyrone is one of the most widely used painkillers in the postoperative period in children. Its use, however, is controversial in the literature, to the point that it is banned in many countries due to its potential severe adverse effects. Because of this controversy, reviewing the analgesic use of dipyrone in the postoperative period of tonsillectomy in children is essential.

OBJECTIVE

The aim of this study was to review the analgesic use of dipyrone in the postoperative period of tonsillectomy in children.

METHODS

Systematic review of the literature, involving an evaluation of the quality of articles in the databases MEDLINE/Pubmed, EMBASE and Virtual Health Library, selected with a preestablished search strategy. Only studies with a randomised clinical trial design evaluating the use of dipyrone in the postoperative period of tonsillectomy in children were included.

RESULTS AND CONCLUSION

Only 2 randomised clinical trials were found. Both compared dipyrone, paracetamol, and placebo. We were unable to carry out a metanalysis because the studies were too heterogenous (dipyrone was used as pre-emptive analgesic in one and only postoperatively in another). The analgesic effect of dipyrone, measured by validated pain scales in childhood, was shown to be superior to placebo and similar to paracetamol. It appears that dipyrone exhibits a profile suitable for use in children. However, the scarcity of randomised clinical trials evaluating its analgesic effect in this age group leads to the conclusion that more well-designed studies are still needed to establish the role of dipyrone in the postoperative period of tonsillectomy in children.

Liver Injury Associated with Metamizole Exposure: Features of an Underestimated Adverse Event

INTRODUCTION AND OBJECTIVE

The potential of metamizole to cause drug-induced liver injury (DILI) has received increasing attention. We investigated the distinguishing features of a case series comprising 32 patients with suspected metamizole-induced DILI.

METHODS

For the current analysis, 32 of 238 patients with DILI included in our prospective study on drugs potentially causing DILI were included. Diagnosis of DILI was based on expert opinion and RUCAM (Roussel Uclaf Causality Assessment Method) score and supported by an in vitro test using monocyte-derived hepatocyte-like cells.

RESULTS

Suspected metamizole-DILI was characterised by a female predominance, hepatocellular pattern of injury, high proportion of antinuclear antibody positivity, and predominance of eosinophilic cell infiltration and necrosis in the histopathological analysis. With 22%, a high proportion of these metamizole-associated liver injury cases developed acute liver failure, which was characterised by a longer latency of metamizole use and more pronounced liver biochemistry abnormalities at onset and peak levels. Furthermore, jaundice was a common finding in the metamizole-associated liver injury cases with 66% presenting with peak bilirubin levels of 3 mg/dL or higher, which was associated with a worse outcome and a higher frequency of acute liver failure.

CONCLUSIONS

Our analysis of a well-characterised DILI cohort further supports the potential of metamizole causing DILI and provides important features for the establishment of a signature pattern of liver injury observed in patients treated with metamizole.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02353455.

[Considerations concerning the perioperative use of metamizole]

BACKGROUND

The non-opioid analgesic metamizole (dipyrone) is approved for the treatment of severe pain and is often used in the perioperative period. As it can cause agranulocytosis, a severe adverse event, its perioperative administration is controversially discussed.

OBJECTIVE

Is there enough evidence for a high risk of metamizol-induced agranulocytosis (MIA)? What are the consequences of its perioperative use with respect to the risk profiles of alternative analgesics?

MATERIAL AND METHODS

Rapid review of the literature on the risk of MIA and adverse effects of non-opioid analgesics.

RESULTS

The incidence of MIA is estimated to be one case per million inhabitants per year. The risk seems low compared to other drugs associated with a risk of agranulocytosis, such as antithyroid drugs and ticlopidine. The risk profile of metamizole concerning hepatotoxicity, nephrotoxicity, bleeding and cardiovascular adverse effects is favorable compared to other non-opioid analgesics. None of the non-opioid analgesics are licensed to be administered intraoperatively.

CONCLUSION

The perioperative use of metamizole is possible after a thorough evaluation of the indications as it provides good analgesia with a generally favorable side effect profile and is administered intravenously. The risk of agranulocytosis is small but needs to be mentioned during patient informed consent in order to optimize early recognition. Intraoperative administration aims at reducing the expected severe postoperative pain. A documentation and justification for the evaluation of the indications are recommended.

Spezielle Schmerztherapie bei rheumatischen Erkrankungen

Schmerz als Hauptsymptom vieler chronisch-entzündlicher Erkrankungen stellt für den Patienten, aber auch für den behandelnden Arzt besonders in seiner chronifizierten Form eine große Herausforderung dar. Es gibt leider keine „Wunderpille“ mit der man Schmerzen für jeden gleich zuverlässig beseitigen kann. Es gibt aber viele Ansätze pharmakologischer als auch nicht-pharmakologischer Art und deren Kombination, um für den einzelnen Patienten wirksame Behandlungsstrategien zu finden. Um diese Strategien für jeden Patienten individuell optimal festzulegen, bedarf es zum einen eines fundamentierten Wissens über das Spektrum zur Verfügung stehender Mittel, zum anderen aber auch Erkenntnis darüber, wie diese sinnvoll nach Art der vorliegenden Schmerzformen einzusetzen sind. In dieser Übersicht wird beides behandelt, mit einem Fokus auf die medikamentöse Therapie von Schmerzen bei entzündlich-rheumatischen Erkrankungen. Dabei wird herausgearbeitet, dass es für die in diesem Zusammenhang relevantesten Formen des Schmerzes, akut-entzündlich nozizeptiv, neuropathisch und durch periphere und zentrale Sensibilisierung chronifizierte Schmerzen, jeweils andere wirksame Konzepte gibt.

Fungal Periprosthetic Knee Joint Infection in a Patient with Metamizole-Induced Agranulocytosis

We present the case of a 55-year-old female patient with metamizole-induced agranulocytosis after total knee arthroplasty, leading to septic periprosthetic joint infections (PJIs). Owing to metamizole-induced agranulocytosis, the synovial leukocyte count was negative. Here, we discuss the diagnostic challenges evolving from sepsis and neutropenia in patients with suspected PJIs. We suggest an urgent surgical approach, mainly focusing on the clinical presentation preoperatively. Later, our patient developed candidemia and periprosthetic tissue samples were positive for Candida albicans. For fungal PJIs, long-term follow-up studies are lacking and therapeutic recommendations differ. Here, we present our therapeutic approach, including staged revision and 12 weeks of systemic antifungal therapy, and discuss recent findings regarding the therapy of fungal PJIs.

Intra-operative methadone effect on quality of recovery compared with morphine following laparoscopic gastroplasty: a randomised controlled trial

The effect of intra-operative intravenous methadone on quality of postoperative recovery was compared with morphine after laparoscopic gastroplasty. We included 137 adult patients with a body mass index > 35 kg.m^-2 who underwent bariatric surgery. Patients were allocated at random to receive either intra-operative methadone (n = 69) or morphine (n = 68). All patients received the same postoperative care and analgesia. The primary outcome of postoperative quality of recovery was assessed using the Quality of Recovery-40 questionnaire total score 24 h after surgery. Secondary outcomes were assessed in the post-anaesthesia care unit the night of the day of surgery (T1), in the morning after surgery (T2); and at night on the day following surgery (T3). The median (IQR [range]) total Quality of Recovery-40 questionnaire score of 194 (190-197 [165-200]) was higher (p < 0.0001) in the methadone group compared with the score of 181 (174-185.5 [121-200]) in the morphine group. In the post-anaesthesia care unit, the pain burden; incidence of nausea and vomiting; rescue morphine dose; and time to discharge, were significantly lower in the methadone group. On the ward, the methadone group had a lower: incidence of rescue morphine requests at T1 (5.8 vs. 54.4%, p < 0.0001) and T2 (0 vs. 20.1%, p < 0.0001); and incidence of nausea (21.7 vs. 41.2%, p = 0.014), compared with the morphine group. We conclude that intra-operative intravenous methadone improved quality of recovery in patients who underwent laparoscopic gastroplasty, compared with intra-operative morphine. Methadone also reduced postoperative pain, postoperative opioid consumption and the incidence of opioid-related adverse events.

Reactive Metamizole Metabolites Enhance the Toxicity of Hemin on the ATP Pool in HL60 Cells by Inhibition of Glycolysis

Metamizole is an analgesic, whose pharmacological and toxicological properties are attributed to N-methyl-aminoantipyrine (MAA), its major metabolite. In the presence of heme iron, MAA forms reactive metabolites, which are toxic for granulocyte precursors. Since decreased cellular ATP is characteristic for MAA-associated toxicity, we studied the effect of MAA with and without hemin on energy metabolism of HL60 cells, a granulocyte precursor cell line. The combination MAA/hemin depleted the cellular ATP stronger than hemin alone, whereas MAA alone was not toxic. This decrease in cellular ATP was observed before plasma membrane integrity impairment. MAA/hemin and hemin did not affect the proton leak but increased the maximal oxygen consumption by HL60 cells. This effect was reversed by addition of the radical scavenger N-acetylcysteine. The mitochondrial copy number was not affected by MAA/hemin or hemin. Hemin increased mitochondrial superoxide generation, which was not accentuated by MAA. MAA decreased cellular ROS accumulation in the presence of hemin. In cells cultured in galactose (favoring mitochondrial ATP generation), MAA/hemin had less effect on the cellular ATP and plasma membrane integrity than in glucose. MAA/hemin impaired glycolysis more than hemin or MAA alone, and N-acetylcysteine blunted this effect of MAA/hemin. MAA/hemin decreased protein expression of pyruvate kinase more than hemin or MAA alone. In conclusion, cellular ATP depletion appears to be an important mechanism of MAA/hemin toxicity on HL60 cells. MAA itself is not toxic on HL60 cells up to 100 µM but boosts the inhibitory effect of hemin on glycolysis through the formation of reactive metabolites.

[Psychopharmacotherapy during the COVID-19 pandemic]

Im Rahmen der aktuellen coronavirus disease 2019(COVID-19)-Pandemie müssen sich viele Bereiche der Medizin umstrukturieren. Dies betrifft auch die Versorgung von Patienten mit psychischen Erkrankungen. Die Therapie psychischer Erkrankungen umfasst psychotherapeutische und psychopharmakologische Interventionen. Letztere können mit einer Vielzahl an unerwünschten Arzneimittelwirkungen (UAW) assoziiert sein, stellen aber in der aktuellen Situation mit Kontakt- und Ausgangsbeschränkungen die präferierte Therapieoption dar. Da der direkte Patientenkontakt zugunsten des Telefonats oder der Videokonferenz reduziert ist, müssen angepasste diagnostische und therapeutische Optionen gefunden werden, um eine ausreichende Patientensicherheit zu gewährleisten. Bedeutend sind hierbei die ausführliche Aufklärung der Patienten sowie eine aktive Abfrage von Symptomen zur rechtzeitigen Erkennung von UAW. Unter der Behandlung mit Psychopharmaka sind UAW zu befürchten, die besonders ungünstig sind, wenn sie im Rahmen einer akuten Infektion auftreten oder ein erhöhtes Infektionsrisiko begünstigen. Hierzu gehören Atemdepression, Agranulozytose, Intoxikation durch Hemmung des Arzneistoffmetabolismus und venöse Thromboembolien, die jeweils mit potenziell lebensbedrohlichen Folgen einhergehen. Gleichzeitig sollte auf eine ausreichende Wirksamkeit der Medikation geachtet werden, da die gegenwärtige Krise zu einer Exazerbation vorbestehender psychischer Erkrankungen führen bzw. deren Erstmanifestation begünstigen kann.

[Agranulocytosis after use of metamizole - an underestimated risk?]

OBJECTIVE

Metamizole was the second most common drug prescribed in Germany in 2018 despite the known risk of agranulocytosis and the strict indication. According to Stammschulte et al. up to 25 % of all prescriptions are off-label use. 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.

MATERIAL AND METHODS

Retrospective analysis of eight cases metamizole-induced agranulocytosis over a period of five years (2016-2020) in the university ENT department in Erlangen. Five patients were men and three women. Mean age of diagnosis was 52,4 years (± 25,6).

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, dysphagia and tonsillitis in combination with abscesses in the head and neck area result in the detection of a metamizole-induced agranulocytosis. An agranulocytosis provokes partially radical surgery and/ or intensive-care measures and could lead to sepsis with organ failure or even to death.

CONCLUSIONS

These patient cases show that 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 patient education as well as 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.

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.

Challenges in diagnosis and management of neutropenia upon exposure to immune-checkpoint inhibitors: meta-analysis of a rare immune-related adverse side effect

BACKGROUND

Cancer immunotherapy via immune-checkpoint inhibition (ICI) by antibodies against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and cell death protein 1 (PD-1) have significantly improved the outcome of metastasized melanoma and of a rapidly increasing number of other cancer types. The anti-tumor effect is often accompanied by immune-related adverse events (irAE). Hematological irAE, specifically neutropenia, are rarely observed. However, neutropenia is associated with high morbidity and mortality due to infection complications. Thus, early detection and treatment is crucial.

METHODS

We present the clinical course of two patients with severe neutropenia after ICI therapy and demonstrate the difficulty of the diagnosis when a comedication of metamizole, a well-known analgesic drug used to treat cancer pain, is present. Further, we provide a comprehensive descriptive and statistical analysis of published data on diagnostics, treatment and infection complication in patients with at least grade 4 neutropenia by a systematic database search.

RESULTS

Finally, 34 patients were analyzed, including the two case reports from our cohort. The median onset of neutropenia was 10.5 weeks after first ICI administration (interquartile range: 6 weeks). In 76% (N = 26), a normalization of the neutrophil count was achieved after a median duration of neutropenia of 13 days. In a subsample of 22 patients with detailed data, the infection rate was 13%, proven by positive blood culture in 3 cases, but 68% (N = 15) presented with fever > 38 °C. Treatment regime differed relevantly, but mainly included G-CSF and intravenous corticosteroids. Death was reported in 14 patients (41%), 3 of whom (9%) were associated with hematological irAE but only two directly associated with neutropenia.

CONCLUSION

With an increasing number of cancer patients eligible to ICI therapy, the incidence of severe hematological toxicities may rise substantially over the next years. Clinicians working in the field of cancer immune therapies should be aware of neutropenia as irAE to provide immediate treatment.

Metamizole: An underrated agent causing severe idiosyncratic drug-induced liver injury

Aims

Drug‐induced liver injury (DILI) is a heterogenous entity leading to liver damage. We have analysed the frequency, biochemical and histological patterns and clinical courses of DILI cases due to metamizole at our tertiary care centre in Hamburg, Germany.

Methods

Consecutive patients with DILI who presented to our clinic were analysed retrospectively. Causes of acute hepatitis other than DILI were excluded.

Results

In total, 154 DILI cases were admitted to our centre from 2008 to 2017. After phenprocoumon, metamizole was the second most frequent putative agent causing DILI (23 of all 154 DILI cases, 14,9%). The biochemical pattern on admission of metamizole‐induced DILI cases was hepatocellular with median levels of alanine transaminase (779 U/L, 64–3532 U/L) by far exceeding median alkaline phosphatase levels (131 U/L, 42–578 U/L). In 17 of the 23 cases (74%) liver biopsy was performed. Moderate to severe inflammatory histological activity and severe centrilobular necrosis (>30%) was present in 76.5 and 35.3%, respectively. Metamizole was involved in 2 DILI cases progressing to acute liver failure, then receiving liver transplantation and still alive at time of assessment. Our data were supported by re‐exposure in 4 patients. Furthermore, a database search for metamizole‐induced liver injury in the European Medicines Agency's database identified about 300 reports on suspected metamizole‐induced DILI in Europe.

Conclusion

Elevation of liver enzymes or acute liver failure are not mentioned in the German drug label of metamizole as potential side effects. Our study reveals that in Germany and Europe, metamizole is a frequent and underrated agent causing DILI.

Metamizole and the risk of drug-induced agranulocytosis and neutropenia in statutory health insurance data

The non-opioid analgesic metamizole (dipyrone) is used for the treatment of acute and chronic pain and fever. Agranulocytosis is known as a serious adverse drug reaction of metamizole with potentially fatal outcome. However, its frequency is controversially discussed. The aim of our study was to determine the risk of metamizole-associated agranulocytosis and neutropenia using statutory health insurance data. We analyzed data from a large German health insurance fund in the period from 2010 to 2013. Metamizole-exposed subjects were identified and compared to a propensity score-matched control cohort. A total of 630,285 metamizole-treated subjects and 390,830 matched control subjects were included. In the metamizole cohort, ICD codes for agranulocytosis and neutropenia appeared more often than in non-users. The relative risk for drug-induced agranulocytosis and neutropenia (D70.1) was 3.03 (95% confidence interval, 2.49 to 3.69). The risk for developing drug-induced agranulocytosis and neutropenia after metamizole prescription was 1: 1602 (CI 95%, 1:1926 to 1:1371). Our results confirm the risk estimation of previous studies. However, the outcome of our study may be confounded by an association of metamizole treatment and chemotherapy. Therefore, consequences for treatment have to be drawn with care.

Metamizole vs. ibuprofen at home after day case surgery: A double-blind randomised controlled noninferiority trial

BACKGROUND

NSAIDs and paracetamol are the cornerstones of pain treatment after day case surgery. However, NSAIDs have numerous contraindications and consequently are not suitable in up to 25% of patients. Metamizole is a non-opioid compound with a favourable gastro-intestinal and cardiovascular profile compared with NSAIDs.

OBJECTIVES

The study aimed to assess if a combination of metamizole and paracetamol is noninferior to a combination of ibuprofen and paracetamol in treating pain at home after painful day case surgery.

DESIGN

A double-blind randomised controlled trial.

SETTING

Single centre.

PATIENTS

Two hundred patients undergoing elective ambulatory haemorrhoid surgery, arthroscopic shoulder or knee surgery, or inguinal hernia repair.

INTERVENTION

Patients were randomly allocated to receive either metamizole and paracetamol (n = 100) or ibuprofen and paracetamol (n = 100) orally for four days.

MAIN OUTCOME MEASURES

Average postoperative pain intensity using a numerical rating scale and use of rescue medication were measured in the postanaesthesia care unit (PACU) and on postoperative days (POD) 1 to 3. A difference in mean numerical rating scale score of 1 point or less was considered noninferior. Adverse effects of study medication and satisfaction with study medication were measured on PODs 1 to 3 by telephone follow-up.

RESULTS

In the PACU, the difference in mean ± SD pain score between metamizole and paracetamol and ibuprofen and paracetamol was 0.85 ± 0.78. From POD 1 to 3, this difference was lower than 1, resulting in noninferiority. Rescue opioid consumption in the PACU and on PODs 1 and 3 was not significantly different between treatment groups. Rescue opioid consumption on POD2 was significantly higher in the ibuprofen and paracetamol group (P = 0.042). Adverse effects of study medication and overall patient satisfaction were similar in both groups.

CONCLUSION

Paracetamol/metamizole and paracetamol/ibuprofen are equally effective in treatment of acute postoperative pain at home after ambulatory surgery with comparable patient satisfaction levels.

TRIAL REGISTRATION

European Union Clinical Trials Register 2015-003987-35.

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.

Metamizole-associated neutropenia: Comparison of patients with neutropenia and metamizole-tolerant patients

Reports of metamizole-induced neutropenia have increased in Switzerland and Germany over the last decades, most likely reflecting increased use of metamizole. To date, there are no effective strategies to identify patients at increased risk of metamizole-induced neutropenia. In this observational, multi-center comparative study, characteristics of patients with metamizole-associated neutropenia were compared with patients treated with metamizole without developing adverse hematological reactions. Patients with metamizole-induced neutropenia treated at the University Hospitals Basel and Bern between 2005 and 2017 were included. Tolerant comparison patients with continuous metamizole treatment (≥500 mg/day for at least 28 days) were recruited from GP offices and community pharmacies. Forty-eight patients with metamizole-induced neutropenia, consisting of 23 and 25 cases with inpatient-acquired and outpatient-acquired neutropenia, respectively, were compared to 39 metamizole tolerant comparison patients. Median latency until first diagnosis of neutropenia was 6 days (1-61 days) in inpatient cases and 19 days (2-204 days) in outpatient cases. There was no association between non-myelotoxic and non-immunosuppressive co-medication (p = .6627), history of drug allergy (p = .1304), and preexisting auto-immune diseases (p = .2313) and the development of metamizole-induced neutropenia. Our results suggest that autoimmune diseases, history of drug allergy, and concomitant treatment with non-myelotoxic and non-immunosuppressive drugs are likely not individual risk factors for metamizole-associated neutropenia.

Acute Liver Failure in a Patient Treated With Metamizole

We report on a patient who developed acute liver failure while being treated with metamizole. After liver transplantation, the patient recovered rapidly. Liver biopsy showed massive necrosis and lobular infiltration of lymphocytes. A lymphocyte transformation test performed 20 months after transplantation was positive for metamizole. In vitro investigations with N-methyl-4-aminoantipyrine (MAA) and 4-aminoantipyrine (AA), the two active metabolites of metamizole, did not reveal relevant toxicity in HepG2 and HepaRG cells. The demonstration of activated lymphocytes by the lymphocyte transformation test and the absence of relevant cytotoxicity by MAA and AA in hepatocyte cell lines suggest an immunological mechanism of metamizole-associated hepatotoxicity.

[Fatal Outcome of Agranulocytosis after Re-Exposure to Metamizole and Cefepime-Induced Encephalopathy]

Fatal Outcome of Agranulocytosis after Re-Exposure to Metamizole and Cefepime-Induced Encephalopathy Abstract. We present the case of an 83-year-old female patient who died as a result of likely drug-induced complications, namely agranulocytosis caused by metamizole and cefepime-induced encephalopathy. Agranulocytosis precipitated a cascade of events that eventually led to death. As prescription of metamizole has increased over the past decades, it is important to keep in mind its serious adverse drug reactions. Metamizole must be stopped immediately at the onset of symptoms such as fever, mucositis and sore throat, and re-exposure in patients who have previously developed leukopenia under metamizole must be avoided. This can be achieved by meticulous documentation in the medical records and the use of an emergency or allergy alert card which the patient carries at all times. When using cefepime, renal function should be closely monitored, especially in multimorbid geriatric patients, and the dose should be adjusted accordingly.

Non-steroidal anti-inflammatory drug effects on renal and cardiovascular function: from physiology to clinical practice

Excessive or inappropriate use of non-steroidal anti-inflammatory drugs can affect cardiovascular and renal function. Non-steroidal anti-inflammatory drugs, both non-selective and selective cyclooxygenase 2 inhibitors, are among the most widely used drugs, especially in the elderly, with multiple comorbidities. Exposition to a polypharmacy burden represents a favourable substrate for the onset of non-steroidal anti-inflammatory drug-induced deleterious effects. Cardiovascular and renal issues concerning the occurrence of myocardial infarction, atrial fibrillation, heart failure and arterial hypertension, as well as acute or chronic kidney damage, become critical for clinicians in their daily practice. We discuss current available knowledge regarding prostanoid physiology in vascular, cardiac and renal systems, pointing out potential negative non-steroidal anti-inflammatory drug-related issues in clinical practice.

Pain-Prescription Differences - An Analysis of 500,000 Discharge Summaries

BACKGROUND

Pain-relief prescriptions have led to an alarming increase in drug-related abuse.

OBJECTIVE

In this study, we estimate the pain reliever prescription rates at a major German academic hospital center and compare with the nationwide trends from Germany and prescription reports from the USA.

METHODS

We analysed >500,000 discharge summaries from Charité, encompassing the years 2006 to 2015, and extracted the medications and diagnoses from each discharge summary. Prescription reports from the USA and Germany were collected and compared with the trends at Charité to identify the frequently prescribed pain relievers and their world-wide utilization trends. The average costs of pain therapy were also calculated and compared between the three regions.

RESULTS

Metamizole (dipyrone), a non-opioid analgesic, was the most commonly prescribed pain reliever at Charité (59%) and in Germany (23%) while oxycodone (29%), a semi-synthetic opioid, was most commonly ordered in the USA. Surprisingly, metamizole was prescribed to nearly 20% of all patients at Charité, a drug that has been banned for safety reasons (agranulocytosis) in most developed countries including Canada, United Kingdom, and USA. A large number of prospective cases with high risk for agranulocytosis and other side effects were found. The average cost of pain therapy greatly varied between the USA (125.3 EUR) and Charité (17.2 EUR).

CONCLUSION

The choice of pain relievers varies regionally and is often in disagreement with approved indications and regulatory guidelines. A pronounced East-West gradient was observed with metamizole use and the opposite with prescription opioids.

The use of dipyrone in the ICU is associated with acute kidney injury: A retrospective cohort analysis

BACKGROUND

Use of dipyrone (metamizole) in perioperative and ICU pain therapy remains controversial due to a lack of solid evidence weighing dipyrone benefit against its potential life-threatening complications. Although dipyrone has known analgesic and antipyretic properties, its mechanisms of actions are incompletely understood. Although dipyrone effects on renal vasodilator prostaglandin synthesis are documented, little is known about its potential renal side effects, especially in the critical care environment.

OBJECTIVE

Investigation of the perioperative nephrotoxic potential of dipyrone in patients prone to acute kidney injury (AKI).

DESIGN

Retrospective cohort study.

SETTING

Single centre study in a tertiary referral hospital from January 2013 until June 2013.

PATIENTS

A total of 500 consecutive patients aged 18 years and older referred to the anaesthesia ICU. Patients were excluded if admitted from or discharged to other ICUs, if referred for post resuscitation care, or if repeatedly admitted to the ICU.

MAIN OUTCOME MEASURES

Incidence of AKI, as defined by the Kidney Disease: Improving Global Outcomes Acute Kidney Injury Work Group criteria, and duration of vasopressor therapy.

RESULTS

Use of dipyrone was associated with an increased incidence of AKI in a dose-dependent manner with a 1.6-fold increase in the incidence of AKI with each additional gram of intravenous dipyrone per day. Dipyrone dose of more than 2.5 g day was the best risk predictive cut-off for AKI. Patients receiving dipyrone on the ICU presented with a prolonged duration of vasopressor therapy.

CONCLUSION

Increasing dipyrone dosage is a potential independent risk factor for AKI in adult ICU patients and may prolong vasopressor therapy. Clinical evidence for a benefit of dipyrone therapy in the ICU is insufficient and needs further critical evaluation.

Drug use in the management of uncomplicated malaria in public health facilities in the Democratic Republic of the Congo

Background

Malaria the first causes of death from parasitic infection worldwide. Interventions to reduce the burden of malaria have produced a tremendous drop in malaria morbidity and mortality. However, progress is slower in DRC, which shares with Nigeria 39% of deaths related to malaria globally. Inappropriate use of drugs may be one of the factors of this below-average performance. The aim of this study was to describe the use of drugs in the management of uncomplicated malaria in public health facilities in DRC.

Methods

A drug use study was carried out in DRC from January to March 2014. In each of the former 11 provinces of DRC, one Rural Health Centre, one Urban Health Centre and one General Hospital were selected. In each of them, 100 patient’s files containing prescription of anti-malarials from January to December 2013 were randomly selected. Among them, all of the files with diagnosis of uncomplicated malaria were included in this study. Prescribed anti-malarials, co-prescribed drugs and their indications were collected. Descriptive analyses were performed.

Results

A total of 2300 files out of 3300 (69.7%) concerned uncomplicated malaria and were included in analysis. Malaria treatment was initiated after a positive RDT or microscopy in 51.5% of cases, upon suspicion without requesting biological confirmation in 37% and despite negative results in 11%. Twenty-nine (29) different treatment regimens were used. The drugs recommended by the National Malaria Control Programme were used in 54.3% of cases (artesunate–amodiaquine 37.4% or artemether–lumefantrine 16.9%). The second most used anti-malarial was quinine (32.4%). Apart from anti-malarials, an average of 3.1 drugs per patient were prescribed, among which antibiotics (67.9%), analgesics and non-steroidal anti-inflammatory (NSAIDs) (all abbreviations to be explicated on first use) (70.6%), vitamins (29.1%), anaemia drugs, including blood transfusion (9.1%) and corticosteroids (5.7%), In 51.4% of cases there was no indication for the concomitant medication.

Conclusion

Management of uncomplicated malaria in DRC is characterized by a low adherence to treatment policy, numerous treatment regimens, and abundant concomitant medication potentially harmful to the patient. This may contribute to the low performance of DRC in malaria control. Determinant of this irrational use of drugs need to be assessed in order to formulate and implement efficient corrective measures.

[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.

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 Drug Prescription Patterns on Five International Paediatric Wards

AIM

Analgesic and anti-inflammatory drugs are frequently prescribed in paediatrics. Prescribing and dosing patterns in hospitalised children are not well known. This study explores analgesic drug utilisation on five paediatric wards and discusses its findings in comparison with World Health Organization (WHO) guidelines.

METHOD

A sub-analysis of a prospective, multicentre, observational cohort study was undertaken. Prescription data of children aged up to ≤18 years were collected between October 2008 and December 2009 on paediatric general medical wards in five hospitals in Australia, Germany, the United Kingdom (UK), Hong Kong (HK) and Malaysia. Analgesic drug prescriptions were analysed for prescribing patterns in terms of dosing, frequency and route of administration. Dosing data were compared with local recommendations and WHO guidelines for children.

RESULTS

In the study cohort, 56.8 % (726/1278) of paediatric patients received at least one analgesic drug prescription (1227 prescriptions). The median age of patients with analgesics was 2.2 years [interquartile range (IQR) 0.8-7.3], and the median number of prescriptions per patient was one (IQR 1-2). The most commonly prescribed drugs were oral paracetamol (45.9 %, 563/1227) and oral ibuprofen (19.9 %, 244/1227). Daily doses of paracetamol ranged from 30 mg/kg/day in Germany to 67-68 mg/kg/day in the UK and HK (p < 0.05). For ibuprofen, single doses ranged from 5-6 mg/kg in HK and the UK to 10 mg/kg in Germany and Australia (p < 0.001). Opioid use prevalence was statistically different between the centres and ranged from 0 to 17.6 % (p < 0.001).

CONCLUSION

This study provides a comprehensive overview of analgesic drug use of hospitalised children. Similar to primary care data, paracetamol is the most commonly used analgesic. As recommended by WHO guidelines, oral medication was favoured and opioids used in addition to paracetamol and ibuprofen. Overall drug utilisation was in line with local recommendations and WHO guidelines. Differences in use of paracetamol and ibuprofen among countries were seen, indicating that safety concerns are perceived differently. More large-scale safety studies are needed.