Drug-induced agranulocytosis in the Berlin case–control surveillance study

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.

Neutropenia in Childhood-A Narrative Review and Practical Diagnostic Approach

Neutropenia refers to a decrease in the absolute neutrophil count according to age and race norms and poses a common concern in pediatric practice. Neutrophils serve as host defenders and act crucially in acute inflammation procedures. In this narrative review, we systematically present causes of neutropenia in childhood, mainly adopting the pathophysiological classification of Frater, thereby studying (1) neutropenia with reduced bone marrow reserve, (2) secondary neutropenia with reduced bone marrow reserve, and (3) neutropenia with normal bone marrow reserve. Different conditions in each category are thoroughly discussed and practically approached from the clinician's point of view. Secondary mild to moderate neutropenia is usually benign due to childhood viral infections and is expected to resolve in 2-4 weeks. Bacterial and fungal agents are also associated with transient neutropenia, although fever with severe neutropenia constitutes a medical emergency. Drug-induced and immune neutropenias should be suspected following a careful history and a detailed clinical examination. Cytotoxic chemotherapies treating malignancies are responsible for severe neutropenia and neutropenic shock. Rare genetic neutropenias usually manifest with major infections early in life. Our review of taxonomies clinical findings and associates them to specific neutropenia disorders. We consequently propose a practical diagnostic algorithm for managing neutropenic children.

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.

Facts and trends in dental antibiotic and analgesic prescriptions in Germany, 2012-2021

OBJECTIVES

The study aims to overview German dentists' development of antibiotic and analgesic prescriptions from 2012 to 2021.

MATERIALS AND METHODS

A longitudinal database analysis was performed based on the annual reports of the "Research Institute for Local Health Care Systems" (WIdO, Berlin).

RESULTS

From 2012 until 2021, dental antibiotic prescriptions fell by 17.9%. In contrast, the dental proportion of antibiotic prescriptions compared to all antibiotic prescriptions in Germany increased from 9.1 to 13.6%. Aminopenicillins enhanced their share from 35.6 to 49.4%, while clindamycin prescriptions declined from 37.8 to 23.4%. The proportion of ibuprofen prescriptions significantly increased from 60.4% in 2012 to 79.0% in 2021.

CONCLUSIONS

Since 2013, the most frequently prescribed antibiotic by German dentists has been amoxicillin reaching nearly half of all dental antibiotic prescriptions in 2021. Simultaneously, the proportion of clindamycin has steadily decreased, but the level is still high compared to international data. During the past decade, ibuprofen as a first-line analgesic in German dentistry was continuously gaining in importance.

CLINICAL RELEVANCE

Aminopenicillins have the best risk-benefit balance in dentistry, but the use of antibiotics generally must be limited only to cases of severe infections or compromised patients. Pre-existing diseases or permanent medications should always be considered when choosing an analgesic.

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.

Does ibuprofen, prednisolone, or amoxicillin reduce post-tonsillectomy pain in children? A prospective randomized controlled trial

OBJECTIVE

To evaluate whether the use of anti-inflammatory or antibiotic in the postoperative period modifies pain in children undergoing tonsillectomy.

METHODS

225 children who underwent cold knife tonsillectomy ± adenoidectomy were randomized into five groups, receiving #1 metamizole/acetaminophen, #2 amoxicillin, #3 ibuprofen, #4 prednisolone, or #5 amoxicillin plus prednisolone. All groups received oral analgesics (metamizole/acetaminophen) to use as needed. Pain was monitored during the 7 days following surgery using the Parents' Postoperative Pain Measurement (PPPM) and the Faces Pain Scale - Revised (FPS-R). Pain was also indirectly evaluated by the dose of analgesics administered on each day and by the time needed to return to a solid diet.

RESULTS

After losses (24%), 170 individuals were submitted for analysis. Multiple comparisons demonstrated that the evolution of pain between the different groups, as matched day-per-day, was not significantly different by either PPPM or FPS-R (p > 0.05). The instances of analgesic intake were also similar in all the groups (p > 0.05), as was the return to solid food ingestion (p = 0.41). All groups presented a similar standard of clinical improvement at intervals of 2 days (p < 0.01). Independent of postoperative pain management, patients developed significant pain up to the day 4 following surgery.

CONCLUSION

The addition of amoxicillin, ibuprofen, prednisolone, or amoxicillin and prednisolone does not modify postoperative pain in children undergoing cold-knife tonsillectomy. Special pain control should be performed on the first 4 days following tonsillectomy in children.

Rare case of pancrelipase therapy-induced neutropaenia

A 61-year-old man was transferred to our facility from an outside hospital due to refractory neutropaenia of unknown aetiology. The patient presented to the referring hospital with a 5-day history of worsening diarrhoea and abdominal pain. Initial lab results at presentation showed severe neutropaenia with an absolute neutrophil count of 0. Investigations included a bone marrow biopsy which showed slightly hypocellular marrow with near absence of granulocytic precursors. A CT without contrast showed evidence of chronic pancreatitis and acute colitis. The patient's neutropaenia persisted despite granulocyte colony-stimulating factor therapy. The patient was, thus, transferred to our facility for a higher level of care. At our facility, the patient had rapid correction of neutropaenia after discontinuation of pancrelipase therapy. The patient's abdominal pain and diarrhoea also improved while off pancrelipase. Neutropaenia has completely resolved 6 weeks after discharge without any further therapy.

[Recommendations for the perioperative use of dipyrone : Expert recommendation of the working group on acute pain of the German Pain Society, the scientific working group on pain medicine of the German Society for Anesthesiology and Intensive Care Medicine and the surgical working group on acute pain of the German Society for Surgery with participation of representatives of the Drug Commission of the German Medical Association]

BACKGROUND

Dipyrone (metamizole) is widely used for perioperative pain management in countries where it is marketed; however, uncertainty exists concerning the safe use of this drug, specifically considering the rare adverse event of an agranulocytosis.

METHODS

As evidence from published studies was lacking, an expert panel developed recommendations for the perioperative use of dipyrone. After a formal, structured consensus process, the recommendations were approved by the involved medical societies.

RESULTS

The panel agreed that blood cell counts shall not be standard for short-term perioperative use in patients unless they are at risk for neutropenia. The medical staff shall be aware of the symptoms and course of action when agranulocytosis is suspected. Patients shall be informed about the risks and benefits of dipyrone and about potential alternatives. The expert group concluded that dipyrone has a relatively positive risk-benefit ratio compared to other nonopioid analgesics. The group strongly recommended educating patients about the symptoms of agranulocytosis if they have received dipyrone over several days and/or treatment is to be continued after discharge, because agranulocytosis can occur several days after discontinuation of metamizole. Further recommendations refer to the information of the physician taking over the patient's care after discharge and the avoidance of re-exposure in patients having previously suffered from dipyrone-induced agranulocytosis.

CONCLUSION

The group's recommendations shall be communicated in order to raise medical staff's and patients' awareness of the appropriate use of dipyrone in the perioperative period.

Idiosyncratic Drug-Induced Neutropenia and Agranulocytosis in Elderly Patients

Agranulocytosis is a rare, but serious and life-threatening hematologic disorder in elderly patients. Idiosyncratic drug-induced agranulocytosis (IDIA) has been classically defined by a neutrophil count below 0.5 × 10⁹/L. The annual incidence of IDIA in Europe is about 1.6–9.2 cases per million inhabitants. Increasing age and female sex have been considered as risk factors for the development of this condition. Besides, it is well known that older people take on average more drugs than younger people. This condition is most often associated with the intake of antibacterial agents, antiplatelets, antithyroids, antipsychotics, antiepileptics and nonsteroidal anti-inflammatory drugs (NSAIDs). Initially, agranulocytosis may present without symptoms, but may quickly progress to a severe infection and sepsis. The causative drug should be immediately stopped. In febrile patients, blood cultures and where indicated, site-specific cultures should be obtained and early treatment with empirical broad-spectrum antibiotics started. Even with adequate treatment, the mortality rate is higher in elderly patients reaching up to 20%. Hematopoietic growth factors have proven to be useful as they shorten the duration of neutropenia. However, data on neutropenia and agranulocytosis in the elderly meeting the criteria of evidence-based medicine are still poor in the literature. This review analyzes the results of our experience as well as other published studies of the universal literature.

Clozapine and hematologic adverse reactions: Impact of the Risk Evaluation and Mitigation Strategy program

Introduction

In October 2015, the Food and Drug Administration (FDA) instituted an update to the mandatory Risk Evaluation and Mitigation Strategy (REMS) program for clozapine to improve safety monitoring of hematologic events. However, the impact of the clozapine REMS program on reporting of hematologic adverse events has not been quantified.

Methods

We assessed adverse event reports for agranulocytosis, granulocytopenia, leukopenia, and neutropenia from the FDA Adverse Event Reporting System (FAERS) for a 1-year time period before (October 2014 to September 2015, pre-REMS) and after (October 2015 to September 2016, post-REMS) the implementation of the clozapine REMS program. The AERSMine platform was used to capture historical effect estimates (October 2004 to September 2014). Reporting odds ratios (ROR), proportional reporting ratios (PRR), and corresponding Taylor series 95% confidence intervals (CIs) were calculated for hematologic events with clozapine compared with all other medications using OpenEpi.

Results

Reporting rates for agranulocytosis, granulocytopenia, leukopenia, and neutropenia with clozapine all increased from the pre-REMS to post-REMS time frames, ranging from a 2-fold increase with leukopenia to a 40-fold increase with neutropenia; the composite measure of all hematologic reports had a 12-fold increase. During the post-REMS time frame, the ROR increased by 1691% (111.4, 95% CI 100.6-123.4) compared with the pre-REMS time frame (7.1, 95% CI 5.2-9.6), and the PRR increased by 1280% (83.1, 95% CI 76.8-90.0 vs 6.9, 95% CI 5.1-9.4) for the composite outcome.

Discussion

We observed significant increases in reports of hematologic adverse events with clozapine after the introduction of the clozapine REMS program. Future research should explore the impact of the less stringent exclusionary and discontinuation criteria on utilization (eg, expanded access) and clinical outcomes (eg, treatment effectiveness and adverse events).

Drug interactions in the treatment of rheumatoid arthritis and psoriatic arthritis

BACKGROUND

Treating patients with inflammatory joint diseases (rheumatoid arthritis, psoriatic arthritis) according to established treatment algorithms often requires the simultaneous use of three or more medications to relieve symptoms and prevent long-term joint damage as well as disability.

OBJECTIVE

To assess and give an overview on drug-drug interactions in the pharmacotherapy of inflammatory joint diseases with regards to their clinical relevance.

METHODS

All possible drug combinations were evaluated using three commercially available drug interaction programs. In those cases where only limited/no data were found, a comprehensive hand search of Pubmed was carried out. Finally, the drug-drug interactions of all possible combinations were classified according to evidence-based medicine and a specifically generated relevance-based system.

RESULTS

All three interaction software programs showed consistent results. All detected interactions were combined in clearly structured tables.

CONCLUSION

A concise overview on drug-drug interactions is given. Especially in more sophisticated cases extensive knowledge of drug interactions supports optimisation of therapy and results in improved patient safety.

[Idiosyncratic drug-induced agranulocytosis: 7 year-analysis in a French university hospital]

INTRODUCTION

Idiosyncratic drug-induced agranulocytosis is a rare but potentially serious haematological disorder. The pathophysiological mechanisms are complex and poorly understood. We aimed at investigating agranulocytosis drug related causes from the myelograms with "myeloid maturation arrest" performed in our university hospital over the last seven years.

METHODS

A retrospective analysis of myelograms collected for agranulocytosis was performed from 1st January 2010 to 31th December 2016. We used the method of Bégaud et al. for drug causality assessment.

RESULTS

Among the 104 myelograms analysed, 41 agranulocytosis were drug-induced, whose 28 were idiosyncratic. Among these 28 cases, 26 different drugs were involved. Agranulocytosis was a known adverse reaction in the summary of the product characteristics for 24 drugs, mainly associated with undetermined frequency (n=7). Mean onset latency was 38.1 days after starting the drug (calculated for n=23 cases) and granulocyte growth factors were used in 50% of cases without shortening the mean delay of blood count recovery. Bone marrow presented hypereosinophilia in 29% of cases. Pharmacovigilance reporting rate was 48%.

CONCLUSION

A "maturation arrest" in the myelogram is not pathognomonic for idiosyncratic drug-induced agranulocytosis. This rare event require multidisciplinary care involving haematologists, biologists and pharmacovigilance experts. Agranulocytosis reporting rate was high compared with usual adverse drug reaction reporting rate (5 to 10%), probably related to the potential severity of this event.

[Recommendations for the perioperative use of dipyrone : Expert recommendation of the working group on acute pain of the German Pain Society, the scientific working group on pain medicine of the German Society for Anesthesiology and Intensive Care Medicine and the surgical working group on acute pain of the German Society for Surgery with participation of representatives of the Drug Commission of the German Medical Association]

BACKGROUND

Dipyrone (metamizole) is widely used for perioperative pain management in countries where it is marketed; however, uncertainty exists concerning the safe use of this drug, specifically considering the rare adverse event of an agranulocytosis.

METHODS

As evidence from published studies was lacking, an expert panel developed recommendations for the perioperative use of dipyrone. After a formal, structured consensus process, the recommendations were approved by the involved medical societies.

RESULTS

The panel agreed that blood cell counts shall not be standard for short-term perioperative use in patients unless they are at risk for neutropenia. The medical staff shall be aware of the symptoms and course of action when agranulocytosis is suspected. Patients shall be informed about the risks and benefits of dipyrone and about potential alternatives. The expert group concluded that dipyrone has a relatively positive risk-benefit ratio compared to other nonopioid analgesics. The group strongly recommended educating patients about the symptoms of agranulocytosis if they have received dipyrone over several days and/or treatment is to be continued after discharge, because agranulocytosis can occur several days after discontinuation of metamizole. Further recommendations refer to the information of the physician taking over the patient's care after discharge and the avoidance of re-exposure in patients having previously suffered from dipyrone-induced agranulocytosis.

CONCLUSION

The group's recommendations shall be communicated in order to raise medical staff's and patients' awareness of the appropriate use of dipyrone in the perioperative period.

[Recommendations for the perioperative use of dipyrone : Expert recommendation of the working group on acute pain of the German Pain Society, the scientific working group on pain medicine of the German Society for Anesthesiology and Intensive Care Medicine and the surgical working group on acute pain of the German Society for Surgery with participation of representatives of the Drug Commission of the German Medical Association]

BACKGROUND

Dipyrone (metamizole) is widely used for perioperative pain management in countries where it is marketed; however, uncertainty exists concerning the safe use of this drug, specifically considering the rare adverse event of an agranulocytosis.

METHODS

As evidence from published studies was lacking, an expert panel developed recommendations for the perioperative use of dipyrone. After a formal, structured consensus process, the recommendations were approved by the involved medical societies.

RESULTS

The panel agreed that blood cell counts shall not be standard for short-term perioperative use in patients unless they are at risk for neutropenia. The medical staff shall be aware of the symptoms and course of action when agranulocytosis is suspected. Patients shall be informed about the risks and benefits of dipyrone and about potential alternatives. The expert group concluded that dipyrone has a relatively positive risk-benefit ratio compared to other nonopioid analgesics. The group strongly recommended educating patients about the symptoms of agranulocytosis if they have received dipyrone over several days and/or treatment is to be continued after discharge, because agranulocytosis can occur several days after discontinuation of metamizole. Further recommendations refer to the information of the physician taking over the patient's care after discharge and the avoidance of re-exposure in patients having previously suffered from dipyrone-induced agranulocytosis.

CONCLUSION

The group's recommendations shall be communicated in order to raise medical staff's and patients' awareness of the appropriate use of dipyrone in the perioperative period.

[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.

Beta-lactam-induced severe neutropaenia: a descriptive study

The objectives of this study were to describe the characteristics and natural history of beta-lactam-induced severe neutropaenia and to evaluate the risk of recurrences after another beta-lactam readministration. Reports of pure agranulocytosis associated with a beta-lactam exposure within the 10 days preceding the neutropaenia were extracted from the French Pharmacovigilance Database over the year 2010. Cases with another evident cause or more likely attributable to another drug were excluded. Data were analyzed for demographics, clinical and biological features, prognosis factors, granulocyte colony stimulating factors administration and outcome. Sixty-two cases were included (median age: 65 years). The median duration of treatment before neutropaenia was 16 days. In 47% of cases, the diagnosis was made on a systematic blood cell count. The median neutrophil count at nadir was 0.125 × 10⁹ /L, and bone marrow examination evidenced features of neutrophilic maturation arrest or aplasia in 21 patients, hyperplasia of granulopoietic cells in three and normal findings in five. Three patients developed severe sepsis. All but one recovered a normal blood cell count within 2-56 days after beta-lactam discontinuation. The last patient died from recurrent severe septic shock. No significant effect of granulocyte colony stimulating factor on the mean duration of haematological recovery was found. Among the 21 patients who later received another beta-lactam, two experienced recurrence of the neutropaenia after receiving a beta-lactam from another subfamily. Beta-lactam-induced agranulocytosis was usually observed after prolonged treatment, and severe complications are uncommon. In most patients, a subsequent treatment with another beta-lactam was well tolerated.

Dipyrone is the preferred nonopioid analgesic for the treatment of acute and chronic pain. A survey of clinical practice in German-speaking countries

PURPOSE

Nonopioid analgesics are frequently used for the treatment of acute and chronic pain. Dipyrone is an alternative to NSAIDs and paracetamol, however, data on the frequency of its usage by anaesthesiologists in the perioperative and chronic pain setting are lacking and its adverse reactions are a matter of debate.

METHODS

The link to a questionnaire on the use of nonopioid analgesics (NSAIDs, COX-2 inhibitors, paracetamol, dipyrone) and the safety of dipyrone in the perioperative and chronic pain setting was mailed to anaesthesiologists and pain physicians.

RESULTS

A total of 2237 responses were analysed. About 97.4% of the respondents used nonopioid analgesics for the treatment of acute pain, with 93.8% administering dipyrone, 54.0% NSAIDs, 41.8% COX-2 inhibitors and 49.2% paracetamol. Nonopioid analgesics were administered preoperatively by 22.3%, intraoperatively by 86.1% and postoperatively by 73.0% of the respondents. For chronic pain management, 76.7% of the respondents prescribed oral dipyrone in combination with other nonopioid analgesics; 19.9% used dipyrone as sole nonopioid, whereas 2.9% denied its use. Cases of dipyrone-associated agranulocytosis were observed by 3.5% of the respondents of the acute and 1.5% of the chronic pain questionnaire, respectively. The majority of respondents (acute pain: 73.0%, chronic pain 59.3%) performed no blood cell counts to monitor dipyrone therapy. Patients were rarely informed about possible adverse drug reactions.

CONCLUSIONS

Dipyrone is the preferred nonopioid analgesic in the perioperative and chronic pain setting. Although cases of agranulocytosis occur, benefits apparently outweigh the risks according to anaesthesiologists. Measures like patient information may improve safety.

SIGNIFICANCE

A survey of anaesthesiologist in German-speaking countries revealed dipyrone as preferred nonopioid analgesic for the treatment of acute and chronic pain. Benefits seem to outweigh the risks, specifically the risk of agranulocytosis. Information of medical staff and patients on adverse drug reactions and symptoms of agranulocytosis should be implemented.

[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.

Non-chemotherapy drug-induced neutropenia: key points to manage the challenges

Non-chemotherapy idiosyncratic drug-induced neutropenia (IDIN) is a relatively rare but potentially fatal disorder that occurs in susceptible individuals, with an incidence of 2.4 to 15.4 cases per million population. Affected patients typically experience severe neutropenia within several weeks to several months after first exposure to a drug, and mortality is ∼5%. The drugs most frequently associated with IDIN include metamizole, clozapine, sulfasalazine, thiamazole, carbimazole, amoxicillin, cotrimoxazole, ticlopidine, and valganciclovir. The idiosyncratic nature of IDIN, the lack of mouse models and diagnostic testing, and its low overall incidence make rigorous studies to elucidate possible mechanisms exceptionally difficult. An immune mechanism for IDIN involving neutrophil destruction by hapten (drug)-specific antibodies and drug-induced autoantibodies is frequently suggested, but strong supporting evidence is lacking. Although laboratory testing for neutrophil drug-dependent antibodies is rarely performed because of the complexity and low sensitivity of tests currently in use, these assays could possibly be enhanced by using reactive drug metabolites in place of the parent drug. Patients typically experience acute, severe neutropenia, or agranulocytosis (<0.5 × 10⁹ neutrophils/L) and symptoms of fever, chills, sore throat, and muscle and joint pain. Diagnosis can be difficult, but timely recognition is critical because if left untreated, there is an increase in mortality. Expanded studies of the production and mechanistic role of reactive drug metabolites, genetic associations, and improved animal models of IDIN are essential to further our understanding of this important disorder.

Sulfasalazine-Induced Agranulocytosis Is Associated With the Human Leukocyte Antigen Locus

Agranulocytosis is a serious, although rare, adverse reaction to sulfasalazine, which is used to treat inflammatory joint and bowel disease. We performed a genome-wide association study comprising 9,380,034 polymorphisms and 180 HLA alleles in 36 cases of sulfasalazine-induced agranulocytosis and 5,170 population controls. Sulfasalazine-induced agranulocytosis was significantly associated with the HLA region on chromosome 6. The top hit (rs9266634) was located close to HLA-B, odds ratio (OR) 5.36 (95% confidence interval (CI) (2.97, 9.69) P = 2.55 × 10^-8 ). We HLA-sequenced a second cohort consisting of 40 cases and 142 treated controls, and confirmed significant associations with HLA-B*08:01, OR = 2.25 (95% CI (1.02, 4.97) P = 0.0439), in particular the HLA-B*08:01 haplotype HLA-DQB1*02:01-DRB1*03:01-B*08:01-C*07:01, OR = 3.79 (95% CI (1.63, 8.80) P = 0.0019), and with HLA-A*31:01, OR = 4.81 (95% CI (1.52, 15.26) P = 0.0077). The number needed to test for HLA-B*08:01 and HLA-A*31:01 to avoid one case was estimated to be 1,500. We suggest that intensified monitoring or alternative treatment should be considered for known carriers of HLA-B*08:01 or HLA-A*31:01.

[Non-opioid pain medication in the elderly]

Non-opioid analgesics are frequently used to control chronic pain in elderly patients; however some of these drugs show high rates of adverse drug reactions. Among these are significant clinical problems which impede an effective and safe pain control. This review provides recent data concerning non-steroidal anti-inflammatory drugs (NSAID), acetaminophen, metamizol and flupirtin. Due to their risk profile NSAIDs are less appropriate due to high incidence rates and drug-related risk patterns. Acetaminophen, metamizol and flupirtin may be recommended instead; however a shortcoming of acetaminophen in comparison to NSAIDs is its weaker action to control pain. Metamizol is still banned in some countries due to rare but potentially severe hematological side effects and flupirtin frequently causes unfavorable sedation.

[Pain medication in nursing home residents with and without cancer. Most frequently with metamizole]

BACKGROUND

Pain is a highly prevalent symptom in nursing home residents. The analgesic pharmacotherapy of older adults is associated with challenges; however, studies from Germany examining the prescription pattern of analgesics in nursing home residents are rare.

OBJECTIVES

This study was carried out to examine the prescription of analgesics in nursing home residents with and without the diagnosis of cancer.

MATERIAL AND METHODS

Using health insurance claims data persons aged ≥ 65 years who were newly admitted to a nursing home between 2004 and 2009 and who survived at least the first 90 days after admission were included in the study. Cancer was identified by outpatient diagnoses of malignant neoplasms (ICD-10: C00-C97). Prescription drugs within the first 90 days after admission to a nursing home were analyzed which means that aspirin and acetaminophen were not taken into account.

RESULTS

A total of 5549 nursing home residents were included, who were on average 81.5 years old (56.8 % females). More than half (53.5 %) were assigned to care level I and 781 (14.1 %) were diagnosed with cancer. The study cohort received on average 7.8 different medications (with vs. without cancer: 8.6 vs. 7.6, respectively) and 43.8 % had prescriptions for analgesics (with vs. without cancer: 52.5 vs. 42.3 %, respectively). A total of 37.1 % were taking WHO step 1 analgesics (step 2: 11.4 % and step 3: 9.2 %). The proportion of persons receiving metamizole (dipyrone) was 28.3 % (with vs. without cancer: 35.6 vs. 27.1 %, respectively). Regarding all prescriptions, metamizole was by far the most frequently prescribed medication in nursing homes followed by melperone and omeprazole.

CONCLUSION

Approximately one third of nursing home residents received metamizole and most were long-term prescriptions. Considering that metamizole is associated with potentially life-threatening adverse effects, caution is indicated particularly when prescribed over long periods.

Safety of metamizole: a systematic review of the literature

WHAT IS KNOWN AND OBJECTIVE

Metamizole was withdrawn from the market in the United States and several European countries following reports of fatal agranulocytosis among users, but is still available in many countries in Europe, South America and Asia. Over the past several decades, a number of epidemiologic studies have been conducted to quantify the risk of agranulocytosis and other adverse effects associated with metamizole and other non-narcotic analgesics. The objective of this study was to perform a systematic review of the safety of metamizole.

METHODS

Epidemiologic studies published between 1 January 1980 and 15 December 2014 were identified through systematic searches of PubMed and Google Scholar; the reference sections of selected articles were also reviewed to identify potentially relevant studies. Studies included in this review focused on the safety of metamizole, that is on outcomes such as haematologic abnormalities, gastrointestinal bleeding, anaphylaxis and hepatotoxicity. Two study investigators independently reviewed the abstracts and articles to determine relevant studies according to prespecified criteria.

RESULTS AND DISCUSSION

A total of 22 articles met the criteria for evaluation. The majority of studies that evaluated agranulocytosis indicated an increased risk associated with metamizole, with relative risk (RR) estimates ranging from 1·5 (95% CI, 0·8-2·7) to 40·2 (95% CI, 14·7-113·3). Findings of three case-control studies do not suggest an association between metamizole and aplastic anaemia. Of the five case-control studies that evaluated the risk of upper gastrointestinal bleeding, four found a statistically significant increased risk associated with metamizole (RR estimates ranging from 1·4 to 2·7). There is insufficient evidence to determine whether metamizole increases the risk of other outcomes (e.g. hepatic effects, anaphylaxis, congenital anomalies). Few studies evaluated the effects of dose, route of administration or duration of therapy.

WHAT IS NEW AND CONCLUSION

Published studies reported differences in the magnitude of risk of adverse outcomes associated with metamizole use and often had small sample sizes and a number of other limitations that may have biased the results. Further research is needed to better quantify the potential risks associated with metamizole compared to other non-narcotic analgesics.

Genetic variants associated with antithyroid drug-induced agranulocytosis: a genome-wide association study in a European population

BACKGROUND

Drug-induced agranulocytosis is a potentially life-threatening adverse reaction. Genome-wide association studies (GWASs) in ethnic Chinese people in Taiwan and Hong Kong have shown an association between agranulocytosis induced by antithyroid drugs and the HLA alleles HLA-B*38:02 and HLA-DRB1*08:03. We aimed to identify genetic variants associated with antithyroid drug-induced agranulocytosis in a white European population.

METHODS

We did a GWAS in 234 European adults with any non-chemotherapy drug-induced agranulocytosis (absolute neutrophil count ≤0·5 × 10(9)/L [≤500/μL]) and 5170 population controls. 39 of the 234 patients had agranulocytosis that was induced by antithyroid drugs (thiamazole [methimazole], carbimazole, or propylthiouracil). After imputation and HLA allele prediction, 9 380 034 single nucleotide polymorphisms (SNPs) and 180 HLA alleles were tested for association. The genome-wide significance threshold was p<5 × 10(-8).

FINDINGS

Agranulocytosis induced by non-chemotherapy drugs in general was significantly associated with the HLA region on chromosome 6, with odds ratios (ORs) of 3·24 (95% CI 2·31-4·55, p=1·20 × 10(-11)) for HLA-B*27:05 and 3·57 (2·61-4·90, p=2·32 × 10(-15)) for the top SNP (rs114291795). Drug-specific analysis showed that the association with HLA-B*27:05 was largely driven by cases induced by antithyroid drugs. In a multiple logistic regression model, the OR for HLA-B*27:05 was 7·30 (3·81-13·96) when antithyroid drug-induced agranulocytosis was compared with population controls (p=1·91 × 10(-9)) and 16·91 (3·44-83·17) when compared with a small group of hyperthyroid controls (p=5·04 × 10(-4)). Three SNPs were strongly associated with antithyroid drug-induced agranulocytosis: rs652888 (OR 4·73, 95% CI 3·00-7·44, p=1·92 × 10(-11)) and rs199564443 (17·42, 7·38-41·12, p=7·04 × 10(-11)), which were independent of HLA-B*27:05, and rs1071816 (5·27, 3·06-9·10, p=2·35 × 10(-9)) which was in moderate linkage disequilibrium with HLA-B*27:05. In heterozygous carriers of all three SNPs, the predicted probability of antithyroid drug-induced agranulocytosis was about 30% (OR 753, 95% CI 105-6812). To avoid one case of agranulocytosis, based on the possible risk reduction if all three SNPs are genotyped and carriers are treated or monitored differently from non-carriers, roughly 238 patients would need to be genotyped.

INTERPRETATION

In white European people, antithyroid drug-induced agranulocytosis was associated with HLA-B*27:05 and with other SNPs on chromosome 6. In the future, carriers of these variants could be placed under intensified monitoring or offered alternative treatment for hyperthyroidism.

FUNDING

Swedish Research Council, Swedish Heart and Lung Foundation, Clinical Research Support at Uppsala University, German Federal Institute for Drugs and Medical Devices, Carlos III Spanish Health Institute, European Regional Development Fund, UK National Institute for Health Research, The Selander's Foundation, Thuréus Foundation, European Commission, and Science for Life Laboratory.

Relation of the Allelic Variants of Multidrug Resistance Gene to Agranulocytosis Associated With Clozapine

Clozapine use is associated with leukopenia and more rarely agranulocytosis, which may be lethal. The drug and its metabolites are proposed to interact with the multidrug resistance transporter (ABCB1/MDR1) gene product, P-glycoprotein (P-gp). Among various P-glycoprotein genetic polymorphisms, nucleotide changes in exons 26 (C3435T), 21 (G2677T), and 12 (C1236T) have been implicated for changes in pharmacokinetics and pharmacodynamics of many substrate drugs. In this study, we aimed to investigate the association between these specific ABCB1 polymorphisms and clozapine-associated agranulocytosis (CAA). Ten patients with a history of CAA and 91 control patients without a history of CAA, despite 10 years of continuous clozapine use, were included. Patient recruitment and blood sample collection were conducted at the Hacettepe University Faculty of Medicine, Department of Psychiatry, in collaboration with the members of the Schizophrenia and Other Psychotic Disorders Section of the Psychiatric Association of Turkey, working in various psychiatry clinics. After DNA extraction from peripheral blood lymphocytes, genotyping was performed using polymerase chain reaction and endonuclease digestion. Patients with CAA had shorter duration of clozapine use but did not show any significant difference in other clinical, sociodemographic characteristics and in genotypic or allelic distributions of ABCB1 variants and haplotypes compared with control patients. Among the 10 patients with CAA, none carried the ABCB1 all-variant haplotype (TT-TT-TT), whereas the frequency of this haplotype was approximately 12% among the controls. Larger sample size studies and thorough genetic analyses may reveal both genetic risk and protective factors for this serious adverse event.

Single dose dipyrone (metamizole) for acute postoperative pain in adults

BACKGROUND

Dipyrone (metamizole) is a nonsteroidal anti-inflammatory drug used in some countries to treat pain (postoperative, colic, cancer, and migraine); it is banned in other countries because of an association with life-threatening blood disorders. This review replaces a 2010 Cochrane review that has been withdrawn.

OBJECTIVES

To assess the analgesic efficacy and associated adverse events of single dose dipyrone for moderate to severe acute postoperative pain using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and LILACS to 11 August 2015; the Oxford Pain Relief Database; two clinical trial registries; and the reference lists of articles.

SELECTION CRITERIA

We included randomised, double-blind, placebo-controlled trials of single dose dipyrone for relief of established moderate to severe postoperative pain in adults. We accepted oral, rectal, intramuscular, and intravenous routes of administration.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered studies for inclusion in the review, assessed risk of bias, and extracted data. We used summed total pain relief or pain intensity difference (TOTPAR or SPID) over four to six hours to calculate the number of participants achieving at least 50% pain relief. From derived results, we calculated the risk ratio and number needed to treat for an additional beneficial outcome (NNT), with 95% confidence intervals (CI), for one participant to experience at least 50% pain relief over four to six hours compared to placebo. We looked at use of rescue medication and time to use of rescue medication as additional measures of efficacy. We also looked for information on adverse events and withdrawals.

MAIN RESULTS

We included eight studies, involving 809 participants, comparing oral dipyrone 500 mg (143 participants), oral dipyrone 1000 mg (57 participants), and intramuscular dipyrone 2000 mg (35 participants) with placebo (236 participants). In addition to placebo, all studies used active controls (ibuprofen, paracetamol, aspirin, flurbiprofen, ketoprofen; 338 participants). Seven studies used the oral route of administration, and one study used the intramuscular route. The mean age ranged from 23 to 62 years. Six studies included both men and women, and two studies included only women. All the studies were small, but were otherwise of moderate to good quality.Over 70% of participants experienced our primary outcome of at least 50% pain relief over four to six hours with oral dipyrone 500 mg compared to 30% with placebo (five studies, 288 participants; NNT 2.4 (95% CI 1.8 to 3.1)) (moderate quality evidence). There were insufficient data to assess other doses or routes of administration of dipyrone.Fewer participants needed rescue medication within four to six hours with dipyrone 500 mg than with placebo (7% with dipyrone versus 34% with placebo; four studies, 248 participants) (low quality evidence).The data on numbers of participants experiencing any adverse event was inconsistently reported and no analysis was possible. No serious adverse events or adverse event withdrawals were reported (very low quality evidence).There were too few data to compare dipyrone directly with other active treatments.

AUTHORS' CONCLUSIONS

Based on very limited information, a single dose of dipyrone 500 mg provides good pain relief to about 70% of people treated, compared to about 30% with placebo. For every five people given dipyrone 500 mg, two people would experience this level of pain relief over four to six hours who would not have done with placebo, and fewer people would need rescue medication.We were unable to compare dipyrone directly with other active treatments, or to assess the effects of different doses or routes of administration, or the number of participants experiencing adverse events, because of insufficient data and inadequate reporting.

The significance of different health institutions and their respective contributions of active pharmaceutical ingredients to wastewater

Active pharmaceutical ingredients (APIs) have been frequently found in the environment. It is, however, still not quite clear who is mainly responsible for API emissions. Hospitals have been considered to be the main contributing point sources for wastewater (WW) discharge of APIs. However, recent studies have shown that the contribution of hospitals to the input of APIs into the aquatic environment is quite low. Due to demographic change and the increase of psychiatric diseases, health institutions (HIs) such as psychiatric hospitals and nursing homes are likely to be important sources as well, but no data is available in this respect. This study aims to assess the impact of HIs and to provide a methodology to measure their respective contributions. Drawing on pharmaceutical consumption data for the years 2010, 2011, and 2012, this study identified API usage patterns for a psychiatric hospital (146 beds), a nursing home (286 inhabitants), and a general hospital (741 beds), the latter of which comprises three separate locations. All the HIs are located in two sub-regions of a county district with about 400,000 citizens in southwestern Germany. A selection of neurological drugs was quantified in the sewer of these facilities to evaluate the correlation between consumption and emission. The API contribution of HIs was assessed by comparing the specific consumption in the facilities with the consumption in households, expressed as the emission potential (IEP). The study shows that the usage patterns of APIs in the psychiatric hospital and the nursing home were different from the general hospital. Neurological drugs such as anticonvulsants, psycholeptics, and psychoanaleptics were mainly consumed in the psychiatric hospital and the nursing home (74% and 65%, respectively). Predicted and average measured concentrations in the effluent of the investigated HIs differed mostly by less than one order of magnitude. Therefore, the consumption-based approach is a useful method to assess usage patterns of APIs in HIs and to predict their respective contributions to WW. The national contribution of HIs on total WW discharge of APIs compared to households was very low. Only the results for the sedative clomethiazole in general hospitals as well as the antidepressant moclobemide and the antipsychotic quetiapine for the nursing homes were found to deserve some attention. The regional comparison showed that in sub-regions with a comparably higher density of HIs, the allocated facilities could be seen as point sources emitting particular APIs. However, in general, the bulk of the consumed pharmaceuticals to WW discharge has to be attributed to households.

[Clinical otorhinolaryngological symptoms of metamizole-induced agranulocytosis]

BACKGROUND

Despite the controversial international debate on the use of metamizole as a standard analgesic, the prescription figures for Germany have increased constantly during recent years. However, metamizole can lead to the rare and severe medical condition called agranulocytosis.

MATERIALS AND METHODS

Between January 2009 and January 2014, 5 patients with metamizole-induced agranulocytosis presented themselves at the Interdisciplinary Emergency Center of the University Clinic Bonn. According to their leading ENT symptoms, they were transferred to the otorhinolaryngological department. We retrospectively evaluated metamizole medication, all general patient data and previous diseases, as well as disease course and the respective therapies.

RESULTS

Within the scope of the different treatments--surgery after trauma (n=2), elective orthopedic surgery (n=2), tonsillitis treatment (n=1)--the patients (n=5; mean age 30 years) had made regular ambulant use of metamizole for several days or weeks (4-28 days, mean 16.8 days). Daily oral dose ranged from 625 to 2000 mg/d (mean 1500 mg/d). Subsequently, patients required treatment for clinical symptoms of agranulocytosis (e.g. tonsillitis with severe odynophagia and significantly reduced general condition). All patients were monitored in an intermediate or intensive care unit (3-14 days, mean 10 days). No patients died.

DISCUSSION

As our cases show, when using metamizole as a standard analgesic, the treating otolaryngologist should look for clinical symptoms of agranulocytosis and inform patients about possible adverse effects. We recommend strict indication setting, regular blood analyses during long-term medication and consideration of alternative analgesics (e.g. NSAR).

Metamizole (dipyrone)-associated agranulocytosis. An analysis of German spontaneous reports 1990-2012

PURPOSE

In 1986, the risk of agranulocytosis prompted German authorities to restrict the indications for metamizole use. After an initial decline, prescriptions increased from <20 million defined daily doses in 1990 to >140 million in 2012. Concurrently, spontaneous reports of agranulocytosis increased from about 10 in 1990 to >50 in 2012. In this study, reports were analyzed to identify targets for risk minimization measures.

METHODS

Reports of suspected metamizole-induced agranulocytosis (neutrophils < 0.5 × 10(9) cells/l) between 1990 and 2012 were identified in the German spontaneous reporting database. Cases for which original reporting documents were available were eligible for analysis. Patient characteristics, indication, clinical course, and outcome were assessed.

RESULTS

One hundred sixty-one reports were analyzed. The mean age of the patients was 56.8 years (11-93) and 64.6 % were female. Off-label use was identified in about 25 % of cases. Neutrophils fell below 100/μl in 63 and intercurrent infections developed in 109 cases. Thirty-eight patients (23.6 %) died. In two thirds of the cases, agranulocytosis occurred within 6 weeks of permanent or intermittent metamizole treatment, in 30.5 % within 7 days, including 18 cases of immediate onset after the first or second administration.

CONCLUSION

The reported cases show severe clinical courses and are, to some extent, a result of off-label use. Due to the absence of individual risk factors and presence of variable onset patterns, risk minimization measures should focus on restricting use to defined clinical situations and providing concise risk information for patients and healthcare professionals.

Genetic determinants of antithyroid drug-induced agranulocytosis by human leukocyte antigen genotyping and genome-wide association study

Graves' disease is the leading cause of hyperthyroidism affecting 1.0–1.6% of the population. Antithyroid drugs are the treatment cornerstone, but may cause life-threatening agranulocytosis. Here we conduct a two-stage association study on two separate subject sets (in total 42 agranulocytosis cases and 1,208 Graves' disease controls), using direct human leukocyte antigen genotyping and SNP-based genome-wide association study. We demonstrate HLA-B*38:02 (Armitage trend P_combined=6.75 × 10⁻³²) and HLA-DRB1*08:03 (P_combined=1.83 × 10⁻⁹) as independent susceptibility loci. The genome-wide association study identifies the same signals. Estimated odds ratios for these two loci comparing effective allele carriers to non-carriers are 21.48 (95% confidence interval=11.13–41.48) and 6.13 (95% confidence interval=3.28–11.46), respectively. Carrying both HLA-B*38:02 and HLA-DRB1*08:03 increases odds ratio to 48.41 (P_combined=3.32 × 10⁻²¹, 95% confidence interval=21.66–108.22). Our results could be useful for antithyroid-induced agranulocytosis and potentially for agranulocytosis caused by other chemicals.

Graves' disease is the leading cause of hyperthyroidism but treatment options can cause life-threatening complications. Chen et al. conduct two-stage direct HLA genotyping and genome-wide association studies to identify HLA-B*38:02 and HLA-DRB1*08:03 as major pharmacogenetic determinants.

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

WHAT IS KNOWN AND OBJECTIVE

Metamizole (dipyrone) is an analgesic that has been the focus of considerable controversy regarding its safety. Because of potentially life-threatening blood disorders such as agranulocytosis, it has been withdrawn in many countries but not in Germany, where prescribing even increased over recent years. We aimed to evaluate prescribing of metamizole in Germany with respect to age, sex and regional variations.

METHODS

Using data of a statutory health insurance, we analysed a cohort of 1·7 million persons who were insured at least 1 day in each quarter of 2009. Outcome of interest was the outpatient prescription prevalence, for example the proportion of persons receiving at least one prescription of metamizole.

RESULTS AND DISCUSSION

A total of 6·8% received metamizole with a higher prescribing prevalence in females (7·8% vs. 6·0%). The prevalence increased with age up to 26·7% in persons ≥85 years (men: 21·1%; and women: 30·4%). We found large regional variations with higher prevalences in the northern part of Germany. Most of the prescriptions were issued by general practitioners (78·9%). 58·3% were liquid oral formulations with considerable regional variations ranging between 32·3% in Mecklenburg-West Pomerania and 67·3% in North Rhine-Westphalia. Overall, liquid oral forms are much more often prescribed in the western than in the eastern part of Germany.

WHAT IS NEW AND CONCLUSION

Metamizole - a drug with a relatively narrow indication - is often prescribed in Germany with relevant differences by age, sex and region. Qualitative studies should clarify reasons for this. Further quantitative research should investigate small-area variations, indications and treatment durations.

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

PURPOSE

Treatment with metamizole (dipyrone) has steadily increased in Germany over the last decade. The consequences of this increase for metamizole-induced agranulocytosis (MIA) are unclear. The present study addressed this topic using data from the Berlin Case-Control Surveillance Study.

METHODS

Adult patients (≥18 years of age) with acute nonchemotherapy-induced agranulocytosis were identified by active surveillance in all 51 Berlin hospitals between 2000 and 2010. Cases related to metamizole were ascertained applying the drug causality criteria of the World Health Organization. The incidence rate of MIA was calculated and standardised by age and sex based on the German standard population in 2010.

RESULTS

Twenty-six MIA cases out of 88 (30 %) patients with validated agranulocytosis were ascertained. The incidence of MIA was 0.96 (95 % confidence interval (CI) 0.95-0.97) cases per million per year. The median age of MIA cases was 50 years (quartile (Q)1 31 years; Q3 68 years) and 19 (73 %) of them were women. In 17 (65 %) cases, neutrophil granulocytes dropped below the value of 0.1 × 10(9) cells/L with three patients suffering from sepsis. Headache and postoperative pain were the most frequent indications for metamizole in outpatients (n = 16) and inpatients (n = 10), respectively. The median treatment duration was 6 days (Q1 4 days; Q3 19 days).

CONCLUSIONS

MIA persists as a severe condition in current pharmacotherapy. The continuous increase of metamizole applications should be critically assessed, especially in regard to indications in the outpatient setting and with respect to metamizole treatment duration.