Modern management of non-chemotherapy drug-induced agranulocytosis: a monocentric cohort study of 90 cases and review of the literature

Ceftriaxone-Induced Reversible Agranulocytosis: A Case Report and Review of Drug-Induced Agranulocytosis

In the modern era of medicine, agranulocytosis is a rare occurrence. Despite significant improvement in patient survival, it still carries significant mortality. Agranulocytosis is most commonly caused by chemotherapeutic agents and numerous non-chemo drugs. As it can develop anytime during treatment and patients can remain asymptomatic, frequent cell count monitoring is an essential tool to make a timely diagnosis. An appropriate drug switch, work up to rule out infection and granulocyte colony-stimulating factor (G-CSF) injection in high-risk cases is the management. The patient should be kept under observation till the resolution of agranulocytosis. We present a case of ceftriaxone-induced agranulocytosis which was completely reversible upon stoppage of drug and granulocyte colony-stimulating factor administration. The pathogenesis of ceftriaxone-induced agranulocytosis is unknown. It is suggested to occur either by an immunologic mechanism or because of direct drug toxicity.

Clopidogrel-induced neutropenia in an 80-year-old patient with chronic kidney disease who underwent percutaneous coronary intervention: a case report and literature review

BACKGROUND

Clopidogrel is a widely-used antiplatelet and acts as an adenosine diphosphate receptor inhibitor. Neutropenia is a rare but serious adverse effect of clopidogrel. It is unknown whether this adverse effect has any association with impaired kidney function.

CASE PRESENTATION

An 80-year-old male with chronic kidney disease was diagnosed with non-ST elevation myocardial infarction and underwent percutaneous coronary intervention. During hospitalization, the patient was diagnosed with contrast-induced nephropathy, treated symptomatically, and discharged with a back-to-baseline creatinine level. Two weeks later, the patient presented to the emergency department with fever and chills. Complete blood count showed leukopenia (0.84 × 10³/mm³) and severe neutropenia (0.13 × 10³/mm³). Blood cultures were positive for Pseudomonas aeruginosa. Clopidogrel was stopped immediately and switched into ticagrelor. Imipenem and granulocyte colony-stimulating factor were administered to the patient. The patient's white blood cell and absolute neutrophil count were within the normal range after four days of treatment. The patient was discharged after a 10-day hospitalization, and his complete blood counts were normal during further follow-ups.

CONCLUSIONS

Clopidogrel was the most likely primary cause of neutropenia in our case. The incidence of clopidogrel-induced neutropenia is low and the exact mechanism is not fully explained. We provide suggestions on the management of clopidogrel-associated neutropenia, and summarize all five cases of clopidogrel-induced neutropenia in patients with impaired kidney function.

Acute antibiotically induced neutropenia: A systematic review of case reports

AIMS

Acute neutropenia induced by antibiotics is a rare side effect of this frequently prescribed class of drugs. We aim to find similarities and differences between reported cases.

METHODS

Through a database search (PubMed, 1968-2020), we identified published case reports and extracted, among other data, patient demographics, duration of treatment with the respective agent, and duration of recovery.

RESULTS

Overall, 83 cases were included. Neutropenia developed after a median (min-max) of 21 (17.5-28.5) days of treatment and was resolved after a median (min-max) of 6 (3.0-8.75) days. Vancomycin and ceftaroline emerged as the two most commonly described antibiotics. In 51.8% of cases, the suspected antibiotic was discontinued; in 37.4% of cases, it was substituted by another agent. Only three case reports mentioned death as a result of neutropenia. The use of granulocyte colony-stimulating growth factors (CSFs) shortened the duration of neutropenia and improved outcome for patients' health.

CONCLUSION

Neutropenia induced by antibiotics remains a rare or rarely reported side effect. Long-term and high-dose treatment regimens expose a higher risk of development. Thus, regular full blood counts are advised during therapy.

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.

Severe Neutropenia and Agranulocytosis Related to Antithyroid Drugs: A Study of 30 Cases Managed in A Single Reference Center

BACKGROUND

The most important series devoted to antithyroid drug-induced severe neutropenia and agranulocytosis are Japanese studies, almost specifically in relation to the intake of methimazole. The clinical data of 30 Caucasian patients followed up for antithyroid drug-induced neutropenia at a third-level hospital are reported. Methods: The data of 30 patients with idiosyncratic antithyroid drug-induced neutropenia and agranulocytosis from a cohort study on drug-induced neutropenia and agranulocytosis conducted at the University Hospital of Strasbourg (France) were retrospectively reviewed. Results: The mean patient age was 61.7 years old (range: 20-87), and the gender ratio (F/M) was 4. Several comorbidities were reported in 23 patients (76.7%), with the mean Charlson comorbidity index of 1. The causative drugs were carbimazole and benzylthiouracil, in 28 (93.3%) and 2 cases, respectively, prescribed primarily for multi-hetero-nodular goiter or thyroid nodule to 18 patients (60%). Sore throat and acute tonsillitis (40%), isolated fever (20%), septicemia (13.3%), documented pneumonia (6.7%), and septic shock (6.7%) were the main clinical features upon admission. The mean neutrophil count at nadir was 0.02 and 0 × 109/L (range: 0-0.3). Regarding the patients' hospital course: 13 cases (43.3%) worsened during hospitalization, severe sepsis was found in 26.7%, systemic inflammatory response syndrome-in 13.3%, and septic shock-in 3.3% of the cases, respectively. Broad-spectrum antibiotics were indicated for all the patients, and 21 (73.3%) of them received hematopoietic growth factors. Hematological recovery (neutrophil count ≥ 1.5 × 109/L) was seen at 8.3 days (range: 2-24), but faster in those receiving hematopoietic growth factors (4.9 days, p = 0.046). Two patients died during hospitalization, and the rest had a favorable clinical outcome. Conclusions: Antithyroid drug-induced neutropenia represents a serious complication resulting from the rates of severe infections especially in those cases severe neutropenia. In this setting, an established procedure for the management of patients seems useful or even indispensable in view of potential mortality.

State of Art of Idiosyncratic Drug-Induced Neutropenia or Agranulocytosis, with a Focus on Biotherapies

INTRODUCTION

Idiosyncratic drug-induced neutropenia and agranulocytosis is seldom discussed in the literature, especially for new drugs such as biotherapies outside the context of oncology. In the present paper, we report and discuss the clinical data and management of this relatively rare disorder, with a focus on biotherapies used in autoimmune and auto-inflammatory diseases.

MATERIALS AND METHODS

A review of the literature was carried out using the PubMed database of the US National Library of Medicine. We searched for articles published between January 2010 and May 2019 using the following key words or associations: "drug-induced neutropenia", "drug-induced agranulocytosis", and "idiosyncratic agranulocytosis". We included specific searches on several biotherapies used outside the context of oncology, including: tumor necrosis factor (TNF)-alpha inhibitors, anti-CD20 agents, anti-C52 agents, interleukin (IL) 6 inhibitors, IL 1 inhibitors, and B-cell activating factor inhibitor.

RESULTS

Idiosyncratic neutropenia remains a potentially serious adverse event due to the frequency of severe sepsis with severe deep tissue infections (e.g., pneumonia), septicemia, and septic shock in approximately two-thirds of all hospitalized patients with grade 3 or 4 neutropenia (neutrophil count (NC) ≤ 0.5 × 109/L and ≤ 0.1 × 109/L, respectively). Over the last 20 years, several drugs have been strongly associated with the occurrence of idiosyncratic neutropenia, including antithyroid drugs, ticlopidine, clozapine, sulfasalazine, antibiotics such as trimethoprim-sulfamethoxazole, and deferiprone. Transient grade 1-2 neutropenia (absolute blood NC between 1.5 and 0.5 × 109/L) related to biotherapy is relatively common with these drugs. An approximate 10% prevalence of such neutropenia has been reported with several of these biotherapies (e.g., TNF-alpha inhibitors, IL6 inhibitors, and anti-CD52 agents). Grade 3-4 neutropenia or agranulocytosis and clinical manifestations related to sepsis are less common, with only a few case reports to date for most biotherapies. Special mention should be made of late onset and potentially severe neutropenia, especially following anti-CD52 agent therapy. During drug therapy, several prognostic factors have been identified that may be helpful when identifying 'susceptible' patients. Older age (>65 years), septicemia or shock, renal failure, and a neutrophil count ≤0.1 × 109/L have been identified as poor prognostic factors. Idiosyncratic neutropenia should be managed depending on clinical severity, with permanent/transient discontinuation or a lower dose of the drug, switching from one drug to another of the same or another class, broad-spectrum antibiotics in cases of sepsis, and hematopoietic growth factors (particularly G-CSF).

CONCLUSION

Significant progress has been made in recent years in the field of idiosyncratic drug-induced neutropenia, leading to an improvement in their prognosis (currently, mortality rate between 5 and 10%). Clinicians must continue their efforts to improve their knowledge of these adverse events with new drugs as biotherapies.

Non-immunological toxicological mechanisms of metamizole-associated neutropenia in HL60 cells

Metamizole is an analgesic and antipyretic, but can cause neutropenia and agranulocytosis. We investigated the toxicity of the metabolites N-methyl-4-aminoantipyrine (MAA), 4-aminoantipyrine (AA), N-formyl-4-aminoantipyrine (FAA) and N-acetyl-4-aminoantipyrine (AAA) on neutrophil granulocytes and on HL60 cells (granulocyte precursor cell line). MAA, FAA, AA, and AAA (up to 100 µM) alone were not toxic for HL60 cells or granulocytes. In the presence of the myeloperoxidase substrate H₂O₂, MAA reduced cytotoxicity for HL60 cells at low concentrations (<50 µM), but increased cytotoxicity at 100 µM H₂O₂. Neutrophil granulocytes were resistant to H₂O₂ and MAA. Fe²⁺ and Fe³⁺ were not toxic to HL60 cells, irrespective of the presence of H₂O₂ and MAA. Similarly, MAA did not increase the toxicity of lactoferrin, hemoglobin or methemoglobin for HL60 cells. Hemin (hemoglobin degradation product containing a porphyrin ring and Fe³⁺) was toxic on HL60 cells and cytotoxicity was increased by MAA. EDTA, N-acetylcystein and glutathione prevented the toxicity of hemin and hemin/MAA. The absorption spectrum of hemin changed concentration-dependently after addition of MAA, suggesting an interaction between Fe³⁺ and MAA. NMR revealed the formation of a stable MAA reaction product with a reaction pathway involving the formation of an electrophilic intermediate. In conclusion, MAA, the principle metabolite of metamizole, increased cytotoxicity of hemin by a reaction involving the formation of an electrophilic metabolite. Accordingly, cytotoxicity of MAA/hemin could be prevented by the iron chelator EDTA and by the electron donors NAC and glutathione. Situations with increased production of hemin may represent a risk factor for metamizole-associated granulocytopenia.

History and Outcome of Febrile Neutropenia Outside the Oncology Setting: A Retrospective Study of 76 Cases Related to Non-Chemotherapy Drugs

BACKGROUND

Despite major advances in its prevention and treatment, febrile neutropenia remains a most concerning complication of cancer chemotherapy. Outside the oncology setting, however, only few data are currently available on febrile neutropenia related to non-chemotherapy drugs. We report here data on 76 patients with febrile neutropenia related to non-chemotherapy drugs, followed up in a referral center within a university hospital.

PATIENTS AND METHODS

Data from 76 patients with idiosyncratic drug-induced febrile neutropenia were retrospectively reviewed. All cases were extracted from a cohort study on agranulocytosis conducted at the Strasbourg University Hospital (Strasbourg, France).

RESULTS

Mean patient age was 52.2 years old (range: 18-93) and gender ratio (F/M) 1.6, with several comorbidities present in 86.8% of patients. The most common causative drugs were: antibiotics (37.4%), antithyroid drugs (17.2%), neuroleptic and anti-epileptic agents (13.1%), non-steroidal anti-inflammatory agents and analgesics (8%), and platelet aggregation inhibitors (8%). Main clinical presentations upon hospitalization included isolated fever (30%), sore throat, acute tonsillitis and sinusitis (18.4%), documented pneumonia (18.4%), septicemia (14.5%), and septic shock (6.6%). Mean neutrophil count at nadir was 0.13 × 10(9)/L (range: 0-0.48). While in hospital, 22 patients (28.9%) worsened clinically and required intensive care unit placement. All patients were promptly treated with broad-spectrum antibiotics, and 45 (59.2%) with hematopoietic growth factors. Mean duration of hematological recovery (neutrophil count ≥1.5 × 10(9)/L) was 7.5 days (range: 2-21), which was reduced to 0.7 days (range: 2-16) (p = 0.089) with hematopoietic growth factors. Outcome was favorable in 89.5% of patients, whereas eight died.

CONCLUSIONS

Like in oncology and myelosuppressive chemotherapy settings, idiosyncratic febrile neutropenia is typically serious, about 40% of patients exhibiting severe pneumonia, septicemia, and septic shock, with a mortality rate of 10%. Like in febrile, chemotherapy-related neutropenia, modern and timely management (immediate broad spectrum antibiotherapy, hematopoietic growth factors) may reduce infection-related mortality. All practitioners should be aware of this potential side-effect that may even occur in the event of "daily medication" exposure.

Non-chemotherapy drug-induced neutropenia - an update

INTRODUCTION

To date, non-chemotherapy drug-induced severe neutropenia (neutrophil count of ≤0.5 x 10⁹/L) also called idiosyncratic drug-induced agranulocytosis is little discussed in the literature. In the present paper, we report and discuss the clinical data and management of this rare disorder. Areas covered: To do this, we carried out a review of the literature using PubMed database of the US National Library of Medicine. We also used data from the American Society of Hematology educational books, textbooks of Hematology and Internal medicine, and information gleaned from international meetings. Expert opinion: Idiosyncratic agranulocytosis remains a potentially serious adverse event due to the frequency of severe sepsis with severe deep tissue infections (e.g., pneumonia), septicemia, and septic shock in approximately two-thirds of all hospitalized patients. In this context, several prognostic factors have been identified that may be helpful when identifying 'susceptible' patients. Old age (>65 years), septicemia or shock, renal failure, and a neutrophil count ≤0.1 × 10⁹/L have been consensually accepted as poor prognostic factors. In our experience, modern management with pre-established procedures, intravenous broad-spectrum antibiotics and hematopoietic growth factors (particularly G-CSF) is likely to improve the prognosis. Thus with appropriate management, the mortality rate is currently between 5 to 10%.

Idiosyncratic Drug-Induced Severe Neutropenia and Agranulocytosis in Elderly Patients (≥75 years): A Monocentric Cohort Study of 61 Cases

BACKGROUND

Little data is currently available in the literature on neutropenia and agranulocytosis in the elderly, and, to our knowledge, idiosyncratic drug-induced agranulocytosis is particularly poorly covered, or not at all.

OBJECTIVE

We herein describe the clinical picture and outcome of patients aged ≥75 years with established idiosyncratic drug-induced agranulocytosis.

PATIENTS AND METHODS

Data from 61 patients over 75 years old with idiosyncratic drug-induced agranulocytosis were retrospectively reviewed. All cases were extracted from a cohort study on agranulocytosis (n = 203) in the Strasbourg University Hospitals (Strasbourg, France), a referral center.

RESULTS

The mean age was 84.9 years (range 75-95), the gender ratio (F/M) was 2.4. Underlying diseases were present in 74 %. The most frequent causative drugs were antibiotics (43.8 %), antithyroid drugs (15.8 %), neuroleptic and anti-epileptic agents (12.3 %), and antiaggregant platelet agents (10.5 %). The primary clinical features during hospitalization included isolated fever (27.6 %), septicemia or septic shock (24.1 %), and pneumonia (20.7 %). The mean neutrophil count at nadir was 0.15 × 109/L (range 0-0.4). All febrile patients were treated with broad-spectrum antibiotics and 36 with hematopoietic growth factors. Outcome was favorable in 85.3 % of patients; nine patients died. Two elderly patients (3.3 %) died of uncontrolled septic shock relating to the depth of the neutropenia. Comparison of mortality between <75- and ≥75-year-old patients revealed a statistical difference: 4.2 % versus 14.8 % (p = 0.023).

CONCLUSIONS

Our study demonstrates that 30 % of idiosyncratic drug-induced agranulocytosis concerned elderly patients. Antibiotic, antithyroid, neuroleptic, anti-epileptic, and antiaggregant platelet agents are the primary causative drug classes. Idiosyncratic drug-induced agranulocytosis is typically serious in this frail population of elderly patients, with at least 50 % suffering from severe sepsis and with a mortality rate of approximately 15 %. Modern management of agranulocytosis may reduce the infection-related mortality (3.3 %).

Nonchemotherapy drug-induced agranulocytosis in children detected by a prospective pharmacovigilance program

OBJECTIVES

A prospective evaluation of nonchemotherapy drug-induced agranulocytosis (DIA) cases, which are infrequent in the pediatric population. We characterize agranulocytosis cases and assess lab test differences between drug- and nondrug-induced agranulocytosis.

METHODS

Through our Prospective Pharmacovigilance Program from Laboratory Signals at Hospital we detected pediatric agranulocytosis cases from July 2007 to December 2010. This program estimates the incidence, drug causality, clinical features, outcomes of DIA pediatric cases, and assesses laboratory differences with respect to non-DIA.

RESULTS

We detected 662 agranulocytosis in 308 pediatric patients, of which 14 were caused by nonchemotherapy drugs. The incidence rate of DIA for 10,000 pediatric patients was 3.92 (Poisson 95% confidence interval 1.09-8.77); 78.6% of DIA cases occurred in patients younger than 3 years. The final outcome was recovery without sequela in all cases. The pharmacologic group most frequently implicated was antimicrobial drugs (11 drugs), 7 of which were beta-lactams. The drugs most frequently suspected were cefotaxime and vancomycin (3 cases each). We found 3 drugs (cloperastine, codeine, and enoxaparin) not previously described to induce DIA. Automatic linear modeling (n = 56, R² = 45.2%) showed a significant inverse association with platelets (R² = 17.5%), hemoglobin, and alanine transaminase, and a direct association with red cell distribution (R² = 16.2%). A generalized linear model (Type III, n = 1188; DIA, n = 86; likelihood ratio chi-squared = 156.16) retained eosinophils (p <.001), platelets (p <.001), total serum proteins (p <.001), and hemoglobin (p =.039).

CONCLUSIONS

We found a higher incidence of DIA in children than previously described. Our findings also suggest an immune-mediated destruction or myeloid toxicity, possibly facilitated by an increase in drug exposure.

Benazepril-Induced Agranulocytosis: A Case Report and Review of the Literature

Patient: Male, 61

Final Diagnosis: Benazepril induced agranulocytosis

Symptoms: Sepsis

Medication: —

Clinical Procedure: None

Specialty: Critical Care Medicine

[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.

[Agranulocytosis related to fluindione: A case report]

INTRODUCTION

While in most countries warfarin is the preferred anti-vitamin K, fluindione, a molecule with a prolonged half-life remains largely prescribed in France. Some of its side effects, including immuno-allergic complications, remain poorly understood.

CASE REPORT

A 77-year-old woman presented with a febrile severe neutropenia of immunoallergic mechanism with a favourable outcome associated with fluindione, introduced 25 days earlier for the treatment of atrial fibrillation.

CONCLUSION

This rare side effect is a reminder of the importance of biological monitoring in the first weeks following the introduction of fluindione and key diagnostic elements and therapeutic aspects of iatrogenic agranulocytosis.

Imatinib-induced agranulocytosis in patients with gastrointestinal stromal tumors

Agranulocytosis is a rare but serious side effect of imatinib in gastrointestinal stromal tumor (GIST) patients. Imatinib is an inhibitor of the proto-oncogene tyrosine kinase (c-kit) and the first-line agent in patients with locally advanced and metastatic GIST. Little evidence is available on the management of this adverse event, and consensus-based guidelines are lacking. In this article, we describe 4 patients with agranulocytosis after starting imatinib. In addition, an overview of the available literature concerning the underlying mechanisms is given, and therapeutic strategies for overcoming this adverse event are discussed. In our experience it appears safe to restart imatinib after normalization of neutrophil count. In case of relapse of agranulocytosis, reintroduction combined with prednisolone, with treatment with granulocyte colony-stimulating factor or dose reduction can be considered.

Nonchemotherapy drug-induced neutropenia and agranulocytosis: could medications be the culprit?

Drug-induced agranulocytosis is a severe complication that has been implicated with most classes of medications. Medications such as clozapine, trimethoprim-sulfamethoxazole and methimazole have been more commonly associated with agranulocytosis than other agents. Although the pathogenesis isn't fully elucidated, it appears to be two-fold with a direct toxicity to the myeloid cell line and immune-mediated destruction. Patients may be asymptomatic at the time neutropenia is discovered or may present with more severe complications such as sepsis. In approximately 5% of cases drug-induced agranulocytosis may be fatal. Management of drug-induced agranulocytosis includes the immediate discontinuation of the offending medication, initiation of broad-spectrum antibiotics and consideration of the use of granulocyte colony-stimulating factors in high-risk patients.

Thyroid disorders

All forms of thyroid diseases are much more frequently observed in women than men, although the reasons are still not completely elucidated.Hyperthyroidism is defined by elevated circulating free thyroid hormones. The prevalence is about 2 % in women and 0.2 % in men. The most frequent causes are various forms of thyroid autonomy in elderly women and Graves' disease, which occurs mostly in younger women.Hypothyroidism is defined by a lack of thyroid hormones. It is a common endocrine disorder caused by autoimmune thyroiditis (Hashimoto thyroiditis), iodine deficiency or following surgery or radioiodine therapy. Thyroxine requirements depend on fat-free mass and are, therefore, somewhat higher in males who are more often undersubstituted. In pregnancy lower TSH-reference ranges have to be considered and thyroid function should be monitored throughout pregnancy to avoid harm to the foetus caused by maternal thyroid dysfunctions. If overtreated women more often feature fractures, whereas males more often develop atrial fibrillation.

Clinical presentation and management of drug-induced agranulocytosis

OBJECTIVE

In this article, we report and discuss the clinical presentation and management of idiosyncratic drug-induced agranulocytosis (neutrophil count <0.5 × 10(9)/l).

RESULTS/CONCLUSIONS

Idiosyncratic drug-induced agranulocytosis remains a potentially serious adverse event owing to the frequency of severe sepsis with severe deep tissue infections (e.g., pneumonia), septicemia and septic shock in approximately two-thirds of all hospitalized patients. However, several prognostic factors have recently been identified that may be helpful in practice to identify 'susceptible' patients. Old age (>65 years), septicemia or shock, metabolic disorders such as renal failure and a neutrophil count below 0.1 × 10(9)/l are currently consensually accepted as poor prognostic factors. In this potentially life-threatening disorder, modern management with broad-spectrum antibiotics and hematopoietic growth factors (particularly granulocyte colony-stimulating factor) is likely to improve prognosis. Thus, with appropriate management, the mortality rate from idiosyncratic drug-induced agranulocytosis is currently approximately 5%.

Bone marrow suppression: a side effect of ciprofloxacin therapy

Ciprofloxacin is a commonly used antibiotic for gastrointestinal and genitourinary tract infections with a considerably good safety profile. However, occasionally it may cause life-threatening complications. Two case reports of bone marrow depression and 1 case of thrombocytopenia due to ciprofloxacin therapy have been reported in literature. We report a case of bone marrow depression due to ciprofloxacin therapy for urinary tract infection in an otherwise healthy woman.

The role of haematopoietic growth factors granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor in the management of drug-induced agranulocytosis

Drug-induced agranulocytosis (neutrophil count <0.5 x 10(9)/l) is a rare haematological complication with an incidence of no more than 10 cases per million inhabitants per year in Europe. Over the past few years there has been a steady decline in mortality rate, (currently at <5%), which can be partly explained by earlier recognition and the improved clinical management of associated intercurrent infections that may lead to severe sepsis if left untreated. The true impact of the use of haematopoietic growth factors, such as granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF), on the decreased mortality rate remains unknown. Yet, most studies show that these molecules, especially G-CSF, reduce the duration of agranulocytosis, antibiotic course and length of hospital stay. Their use is particularly recommended in patients with poor prognostic factors, such as a neutrophil count <0.1 x 10(9)/l, age over 65 years, severe infection or multiple co-morbidities. In all cases, the drug responsible for causing the agranulocytosis must be discontinued and remain permanently contraindicated. The appropriate Medicines Regulatory Agency must also be notified of the adverse event.

Adverse drug reactions affecting blood cells

Numerous medications and other xenobiotics are capable of producing adverse reactions (ADRs) affecting red cells, platelets or neutrophils. Occasionally, more than one blood element is affected simultaneously. As with all drug reactions, some side effects are a direct consequence of a known pharmacologic action of the drug and are dose-dependent; others occur sporadically and relatively independent of dose. The latter ("idiosyncratic") reactions are unpredictable and, in general, have no known underlying genetic basis. Many are antibody-mediated, as would be expected since cellular immune effector cells have little direct access to circulating blood cells. In this chapter, we will discuss idiosyncratic drug reactions affecting blood and blood forming tissues with an emphasis on those thought to be immune-mediated.

Azithromycin-related agranulocytosis in an elderly man with acute otitis media

Azithromycin (AZM) is widely used for respiratory tract infections and otitis media because of its activity against Haemophilus influenzae and atypical pathogens, and its ease of administration. Although leukopenia is the one of the most frequent AZM-related laboratory abnormalities in children, agranulocytosis has not been reported in adults. Here, we present the case of an 81-year-old man with agranulocytosis following AZM-treatment for acute otitis media. He developed febrile neutropenia and granulocyte colony-stimulating factor and cefepim were administered. All his symptoms and absolute neutrophil counts were recovered within 7 days after admission. Physicians must be vigilant in identifying drug-induced neutropenia in AZM-treated patients because early detection can decrease the severity and prevent mortality.

[Idiosyncratic drug-induced agranulocytosis]

Idiosyncratic drug-induced agranulocytosis is a potential adverse event of most drugs, rare but life-threatening. Its annual incidence does not exceed 10 cases per million population in Europe and has remained stable over the past two decades. Its pathogenesis is poorly understood. The principal drugs associated with it are antithyroid drugs, antibiotics including trimethoprim, sulfamethoxazole, and beta-lactamines, ticlopidine, sulfasalazine and dipyrone. Clinical presentation is highly variable but a severe infection is observed in more than one third of cases. Poor prognostic factors include a neutrophil count under 100/mm(3), age > 65 years, septicemia or shock, and severe comorbidity. Improvement in the management of infectious complications and the use of hematopoietic growth factors in severe cases helps explain that mortality rate has fallen to less than 5%.

Non-chemotherapy drug-induced agranulocytosis

Acute agranulocytosis is a rare, potentially life-threatening condition, which is attributable to drugs in > 70% of cases. Agranulocytosis is characterised by a peripheral neutrophil count < 0.5 x 10(9)/l. It often manifests with a severe sore throat, but isolated fever, pneumonia or septicaemia are not uncommon. Agranulocytosis may be caused by many drugs. High-risk drugs include antithyroid drugs, clozapine, ticlopidine, sulfasalazine, dipyrone, trimethoprim/sulfamethoxazole, carbamazepine and probably rituximab. Suspect drugs should be stopped immediately. In febrile patients, blood cultures and, where indicated, site-specific cultures should be obtained and treatment with empirical broad spectrum antibiotics started. Haematopoietic growth factors should be considered in patients with poor prognostic factors (e.g., a neutrophil count < 0.1 x 10(9)/l), severe clinical infection or severe underlying disease or comorbidity. Case fatality has decreased to ~ 5% in recent years, probably owing to improved intensive care treatment and increased alertness of physicians to this severe adverse reaction.

Idiosyncratic drug-induced agranulocytosis: Update of an old disorder

In this paper, we review the literature on idiosyncratic drug-induced agranulocytosis, a rare but life-threatening potential adverse event of most drugs. Articles were identified through MEDLINE searches (1966-2005). Additional references were localized through a review of textbooks on hematology and internal medicine, and information gleaned from international meetings. Additional unpublished data from our cohort with drug-induced agranulocytosis at the University Hospital of Strasbourg, France, were also considered. Searches were done using the following key words: "agranulocytosis", "drug-induced agranulocytosis", and "idiosyncratic agranulocytosis" and were restricted to: English- and French-language, human subjects, clinical trial, review, and guidelines. All of the papers and abstracts were reviewed by at least two senior researchers who selected the data used in the study. What we found is that, over the last 20 years, the incidence of idiosyncratic drug-induced agranulocytosis has remained stable - 2.4-15.4 cases per million - despite the emergence of new causative drugs, mainly antibiotics, antiplatelet agents, and antithyroid drugs. To date, drug-induced agranulocytosis remains a serious adverse event due to the frequency of severe sepsis with severe deep infections (such as pneumonia), septicemia, and septic shock in about two-thirds of all patients. In this setting, old age (>65 years), septicemia or shock, metabolic disorders such as renal failure, and a neutrophil count below 0.1x10(9)/L are poor prognostic factors. Nevertheless, with appropriate management using pre-established procedures, with intravenous broad-spectrum antibiotic therapy, and hematopoietic growth factors, the mortality rate is currently around 5%. Given the increased life expectancy and subsequent longer exposure to drugs, as well as the development of new agents, health care professionals should be aware of this adverse event and its management.

Agranulocytoses médicamenteuses idiosyncrasiques

BACKGROUND

Agranulocytosis is a life-threatening disorder that frequently occurs as an adverse reaction to drugs.

CURRENT DATA

Idiosyncratic drug-induced agranulocytosis is characterized by a neutrophil count <0.5x10(9)/l, in serious forms <0,1x10(9)/l that currently occurs especially in association with antibiotics, antithyroid drugs ant ticlopidine (>60% of the incriminated drugs). The overall incidence of idiosyncratic agranulocytosis ranges from 2.4 to 15.4 cases per million patients exposed to drugs per year. Although patients experiencing idiosyncratic agranulocytosis may be asymptomatic (50%), the severity of the neutropenia usually leads to severe sepsis: fever of unknown origin, septicemia, septic shock or localized documented infections such as sore throat, various cutaneous infections or pneumonia. Nevertheless, the mortality rate of idiosyncratic agranulocytosis is now around 5% with appropriate management.

PERSPECTIVES

In the future, management of drug-induced agranulocytosis may include pre-established procedures using in critically situations, broad-spectrum antibiotic therapy and hematopoietic growth factors (G-CSF).

Life-Threatening Idiosyncratic Drug-Induced Agranulocytosis in Elderly Patients

Agranulocytosis is a life-threatening disorder in any age, but particularly so in elderly patients who are receiving, on average, a larger number of drugs than younger patients. Drug-induced agranulocytosis still remains a rare event, with an annual incidence rate of approximately 3-12 cases per million population. This disorder frequently occurs as an adverse reaction to drugs, particularly antibacterials, antiplatelet agents, antithyroid drugs, antipsychotics or antiepileptic drugs, and NSAIDs. Although patients experiencing drug-induced agranulocytosis may initially be asymptomatic, the severity of the neutropenia usually translates into the onset of severe sepsis that requires intravenous broad-spectrum antibacterial therapy. In this setting, haematopoietic growth factors have been shown to shorten the duration of neutropenia. Thus, with appropriate management, the mortality rate of idiosyncratic drug-induced agranulocytosis is now 5-10%. However, given the increased life expectancy and subsequent longer exposure to drugs, as well as the development of new agents, physicians should be aware of this complication and its management.