Systematic Review of Piperacillin-Induced Neutropenia

Is the fluoroquinolone combination necessary for empirical antibiotic regimen in severe community-acquired pneumonia?

OBJECTIVES

This study aimed to assess whether superior clinical outcomes can be attained through piperacillin/tazobactam (TZP)+fluoroquinolone (FQ) combination therapy for severe community-acquired pneumonia (CAP) compared to TZP monotherapy.

METHODS

This retrospective study was conducted at a tertiary care hospital in Korea. Adult inpatients diagnosed with pneumonia within 48 hours of hospitalization were included. Severe CAP was defined as a CURB-65 score of ≥ 3 or based on the 2007 guidelines of the Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) definition. Only patients who received either TZP and FQ combination or TZP as initial empirical therapy were included.

RESULTS

The final analysis included 145 patients; 57.9% received combination therapy and 42.1% received monotherapy. In the combination therapy group, body mass index (20.67 ± 3.28 vs. 22.26 ± 4.80, p = 0.030) and asthma prevalence (0 vs. 8.3%, p = 0.022) were significantly higher; initial symptoms, clinical severity, and causative pathogens were not significantly different between groups. White blood cell counts (12,641.64 ± 6,544.66 vs. 12,491.67 ± 10,528.24, p = 0.008), and C-reactive protein levels (18.78 ± 11.47 vs. 26.58 ± 14.97, p < 0.001) were significantly higher in the combination therapy group. Clinical outcomes, including all-cause in-hospital mortality rate (26.2 vs. 33.3%, p = 0.358), were not significantly different between the groups. Multivariate analysis identified no significant association between FQ combination and all-cause in-hospital mortality.

CONCLUSION

In patients with severe CAP, there were no differences in the clinical outcomes, including mortality, between the TZP and FQ combination therapy and TZP monotherapy. FQ combination was not significantly associated with in-hospital mortality.

Drug-induced hypersensitivity syndrome related to piperacillin-tazobactam: a case report and review of the literature

Allergic reactions to drugs caused by piperacillin-tazobactam are common in clinical practice. However, we also found a few cases of drug-induced hypersensitivity syndrome (DiHS)/Drug reaction with eosinophilia and systemic symptoms (DRESS) caused by piperacillin-tazobactam in our clinical work. We report a case of a 60-year-old female patient who was treated with piperacillin-tazobactam anti-infective therapy after the diagnosis of hematogenous lung abscess, developed fever, rash, and blood abnormalities after 26 days of application, and was later diagnosed as DIHS, which was improved after the administration of glucocorticoid and anti-allergic drugs. In addition, we also retrospectively analyzed 17 cases of DiHS caused by piperacillin-tazobactam from the PubMed databases between March 1980 and September 2023. The majority of the patients had an incubation period of more than 14 days, and the common clinical features included elevated eosinophil count/percentage, fever, rash, liver damage, and lymph node enlargement. After treatment with topical or systemic glucocorticoids, 16 of the 17 patients improved and one died because of the underlying condition. The clinical features of DiHS were diverse and included a long incubation period, skin rash, elevated eosinophils, and impaired organ function. Since some patients have atypical clinical features, clinicians should raise awareness of the disease, recognize these features early, and treat them promptly.

Beta-Lactam Dose Optimisation in the Intensive Care Unit: Targets, Therapeutic Drug Monitoring and Toxicity

Beta-lactams are an important family of antibiotics used to treat infections and are commonly used in critically ill patients. Optimal use of these drugs in the intensive care unit (ICU) is important because of the serious complications from sepsis. Target beta-lactam antibiotic exposures may be chosen using fundamental principles of beta-lactam activity derived from pre-clinical and clinical studies, although the debate regarding optimal beta-lactam exposure targets is ongoing. Attainment of target exposures in the ICU requires overcoming significant pharmacokinetic (PK) and pharmacodynamic (PD) challenges. For beta-lactam drugs, the use of therapeutic drug monitoring (TDM) to confirm if the desired exposure targets are achieved has shown promise, but further data are required to determine if improvement in infection-related outcomes can be achieved. Additionally, beta-lactam TDM may be useful where a relationship exists between supratherapeutic antibiotic exposure and drug adverse effects. An ideal beta-lactam TDM service should endeavor to efficiently sample and report results in identified at-risk patients in a timely manner. Consensus beta-lactam PK/PD targets associated with optimal patient outcomes are lacking and should be a focus for future research.

Piperacillin/tazobactam and risk of acute kidney injury in adults hospitalized with infection without vancomycin: a multi-centre real-world data analysis

BACKGROUND

There is uncertainty about whether piperacillin/tazobactam (PT) increases the risk of acute kidney injury (AKI) in patients without concomitant use of vancomycin. This study compared the risk of hospital-acquired AKI (HA-AKI) among adults treated with PT or antipseudomonal β-lactams (meropenem, ceftazidime) without concomitant use of vancomycin.

METHODS

This real-world study analysed the data from China Renal Data System and assessed the risk of HA-AKI in adults hospitalized with infection after exposure to PT, meropenem or ceftazidime in the absence of concomitant vancomycin. The primary outcome was any stage of HA-AKI according to the Kidney Disease Improving Global Outcomes guidelines. A multi-variable Cox regression model and different propensity score (PS) matching models were used.

RESULTS

Among the 29,441 adults [mean (standard deviation) age 62.44 (16.84) years; 17,980 females (61.1%)] included in this study, 14,721 (50%) used PT, 9081 (31%) used meropenem and 5639 (19%) used ceftazidime. During a median follow-up period of 8 days, 2601 (8.8%) develped HA-AKI. The use of PT was not associated with significantly higher risk of HA-AKI compared with meropenem [adjusted hazard ratio (aHR) 1.07, 95% confidence interval (CI) 0.97-1.19], ceftazidime (aHR 1.09, 95% CI 0.92-1.30) or both agents (aHR 1.07, 95% CI 0.97-1.17) after adjusting for confounders. Results were consistent in stratified analyses, PS matching using logistic regression or random forest methods to generate a PS, and in an analysis restricting outcomes to AKI stage 2-3.

CONCLUSIONS

Without concomitant use of vancomycin, the risk of AKI following PT therapy is comparable with that of meropenem or ceftazidime among adults hospitalized with infection.

Clinical Pharmacokinetics and Pharmacodynamics of Cefepime

Cefepime is a broad-spectrum fourth-generation cephalosporin with activity against Gram-positive and Gram-negative pathogens. It is generally administered as an infusion over 30-60 min or as a prolonged infusion with infusion times from 3 h to continuous administration. Cefepime is widely distributed in biological fluids and tissues with an average volume of distribution of ~ 0.2 L/kg in healthy adults with normal renal function. Protein binding is relatively low (20%), and elimination is mainly renal. About 85% of the dose is excreted unchanged in the urine, with an elimination half-life of 2-2.3 h. The pharmacokinetics of cefepime is altered under certain pathophysiological conditions, resulting in high inter-individual variability in cefepime volume of distribution and clearance, which poses challenges for population dosing approaches. Consequently, therapeutic drug monitoring of cefepime may be beneficial in certain patients including those who are critically ill, have life-threatening infections, or are infected with more resistant pathogens. Cefepime is generally safe and efficacious, with a goal exposure target of 70% time of the free drug concentration over the minimum inhibitory concentration for clinical efficacy. In recent years, reports of neurotoxicity have increased, specifically in patients with impaired renal function. This review summarizes the pharmacokinetics, pharmacodynamics, and toxicodynamics of cefepime contemporarily in the setting of increasing cefepime exposures. We explore the potential benefits of extended or continuous infusions and therapeutic drug monitoring in special populations.

Broad-Spectrum Antibiotics for Breast Expander/Implant Infection: Treatment-Related Adverse Events and Outcomes

BACKGROUND

Despite best practices, infection remains the most common complication after breast reconstruction with expanders and implants, ranging from 2% to 29%. Empiric broad-spectrum antibiotics are frequently used in nonsurgical treatment of implant-associated infections in an effort to salvage the reconstruction. Pitfalls of antibiotherapy include adverse events, vascular access site complications, and drug resistance. Our goals were to describe management of implant infections with broad-spectrum antibiotics, review treatment related adverse events, and report on outcomes of therapy.

PATIENTS AND METHODS

A retrospective review was carried out to identify patients who were treated with intravenous (IV) antibiotics for periprosthetic infection. Patient characteristics, surgical details, and antibiotic therapy-related adverse events were collected. Eventual outcome related to expander/implant salvage was noted.

RESULTS

A total of 101 patients (111 treatment episodes) were identified. Mean duration of antibiotic treatment was 18 days (range, 1-40 days). The most commonly used parenteral treatment was a combination of daptomycin with piperacillin-tazobactam (65%) or an alternative agent (16%). Fifty-nine percent of treatment episodes resulted in salvage of the expander or implant. Thirty-five percent treatment episodes were associated with 1 or more adverse events: diarrhea (12.6%), rash (10%), vaginal candidiasis (3.6%), agranulocytosis/neutropenic fever (3.6%), nausea (3.6%), urinary complaint (0.9%), myositis (0.9%), headache (0.9%), vascular line occlusion (1.8%), deep vein thrombosis (1.8%), and finger numbness (0.9%). No patients developed Clostridium difficile colitis. Five episodes (4%) needed discontinuation of antibiotics because of severe adverse events. The prosthesis was explanted in 3 of the cases of discontinued treatment.

CONCLUSIONS

Our findings show favorable outcomes and well-tolerated adverse effects with broad-spectrum parenteral antibiotherapy for periprosthetic infection. However, every effort should be made to deescalate therapy by narrowing the spectrum or limiting the duration, to minimize adverse events and development of bacterial resistance. Treating surgeons need to carefully weigh benefits of therapy and be aware of potential complications that might necessitate discontinuation of treatment.

Setting the Beta-Lactam Therapeutic Range for Critically Ill Patients: Is There a Floor or Even a Ceiling?

Beta-lactam antibiotics exhibit high interindividual variability in drug concentrations in patients with critical illness which led to an interest in the use of therapeutic drug monitoring to improve effectiveness and safety. To implement therapeutic drug monitoring, it is necessary to define the beta-lactam therapeutic range-in essence, what drug concentration would prompt a clinician to make dose adjustments up or down. This objective of this narrative review was to summarize evidence for the "floor" (for effectiveness) and "ceiling" (for toxicity) for the beta-lactam therapeutic range to be used with individualized therapeutic drug monitoring.

DATA SOURCES

Research articles were sourced from PubMed using search term combinations of "pharmacokinetics," "pharmacodynamics," "toxicity," "neurotoxicity," "therapeutic drug monitoring," "beta-lactam," "cefepime," "meropenem," "piperacillin/tazobactam," "ICU," and "critical illness."

STUDY SELECTION

Articles were selected if they included preclinical, translational, or clinical data on pharmacokinetic and pharmacodynamic thresholds for effectiveness and safety for beta-lactams in critical illness.

DATA SYNTHESIS

Experimental data indicate a beta-lactam concentration above the minimum inhibitory concentration of the organism for greater than or equal to 40-60% of the dosing interval is needed, but clinical data indicate that higher concentrations may be preferrable. In the first 48 hours of critical illness, a free beta-lactam concentration at or above the susceptibility breakpoint of the most likely pathogen for 100% of the dosing interval would be reasonable (typically based on Pseudomonas aeruginosa). After 48 hours, the lowest acceptable concentration could be tailored to 1-2× the observed minimum inhibitory concentration of the organism for 100% of the dosing interval (often a more susceptible organism). Neurotoxicity is the primary dose-dependent adverse effect of beta-lactams, but the evidence remains insufficient to link a specific drug concentration to greater risk.

CONCLUSIONS

As studies advance the understanding of beta-lactam exposure and response in critically ill patients, it is essential to clearly define the acceptable therapeutic range to guide regimen selection and adjustment.

Risk of acute kidney injury and Clostridioides difficile infection with piperacillin/tazobactam, cefepime and meropenem with or without vancomycin

BACKGROUND

Empiric antimicrobial therapy for healthcare-acquired infections often includes vancomycin plus an antipseudomonal beta-lactam (AP-BL). These agents vary in risk for adverse events, including acute kidney injury (AKI) and Clostridium difficile infection (CDI). Studies have only examined these risks separately; thus, our objective was to simultaneously evaluate AKI and CDI risks with AP-BL in the same patient cohort.

METHODS

This retrospective cohort study included 789,200 Veterans Health Administration medical admissions from July 1, 2010 through June 30, 2016. The antimicrobials examined were vancomycin, cefepime, piperacillin/tazobactam, and meropenem. Cox proportional hazards regression was used to contrast risks for AKI and CDI across individual target antimicrobials and vancomycin combination therapies, including adjustment for known confounders.

RESULTS

With respect to the base rate of AKI among patients who did not receive a target antibiotic (4.6%), the adjusted hazards ratios for piperacillin/tazobactam, cefepime, and meropenem were 1.50 (95% CI: 1.43-1.54), 1.00 (0.95-1.05), 0.92 (0.83-1.01), respectively. Co-administration of vancomycin increased AKI rates (data not shown). Similarly, against the base rate of CDI (0.7%), these ratios were 1.21 (1.07-1.36), 1.89 (1.62-2.20), and 1.99 (1.55-2.56), respectively. Addition of vancomycin had minimal impact on CDI rates (data not shown).

CONCLUSIONS

Piperacillin/tazobactam increased AKI risk, which was exacerbated by concurrent vancomycin. Cefepime and meropenem increased CDI risk relative to piperacillin/tazobactam. Clinicians should consider the risks and benefits of AP-BL when selecting empiric regimens. Further well-designed studies evaluating the global risks of AP-BL and patient specific characteristics that can guide empiric selection are needed.

A Review of β-Lactam-Associated Neutropenia and Implications for Cross-reactivity

OBJECTIVE

To review the incidence, management, and current understanding of the pathophysiology of β-lactam-induced neutropenia and to critically evaluate the practicality and safety of direct substitution to an alternative β-lactam in the setting of this reaction.

DATA SOURCES

A literature analysis using the PubMed and Ovid search engines (July 1968 to October 2020) was performed using the search terms neutropenia, leukopenia, β-lactam, nonchemotherapy, agranulocytosis, and G-CSF (granulocyte colony-stimulating factor).

STUDY SELECTION AND DATA EXTRACTION

The included English-language studies evaluated the incidence, mechanism, and/or management of β-lactam-induced neutropenia in pediatric or adult patients.

DATA SYNTHESIS

Drug-induced neutropenia is a well-documented adverse reaction of β-lactam antibiotics, with an incidence of approximately 10% following at least 2 weeks of intravenous therapy. However, multiple gaps in knowledge remain in the mechanism of pathophysiology and optimal management of this reaction. Both direct toxic and immune-mediated mechanisms have been implicated. Although the cornerstone of management includes cessation of the offending agent, controversy exists on the appropriateness of direct substitution or future use of an alternative β-lactam.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Given the frequency of use and superiority of β-lactams over alternative therapy for several infectious disease states, practical recommendations are needed on the management and safe use of β-lactams following β-lactam-induced neutropenia.

CONCLUSION

Future use of β-lactams with differing R1 side chains, particularly those from a separate class, should not be deemed contraindicated following β-lactam-induced neutropenia and may be considered when indicated, with close laboratory monitoring.

Hematologic adverse effects induced by piperacillin-tazobactam: a systematic review of case reports

Background Piperacillin/tazobactam, a semisynthetic antibiotic, is widely used to treat polymicrobial infections. Its hematologic adverse reactions are rare and the severity can be mild to life-threatening. To our knowledge, there has not been a publication reviewing hematologic abnormalities attributable to piperacillin/tazobactam. Aim of the review To evaluate the characteristic, clinical identification, mechanism and treatment of the hematologic toxicity caused by piperacillin/tazobactam. Method A search of Medline and Embase electronic databases was performed for case reports of adverse reactions of hematologic system related to piperacillin/tazobactam from inception to December 2018. Statistical analysis of demographic, clinical features, laboratory Indexes and treatments was performed using Microsoft EXCEL 2007. Results Fifty-nine references were obtained involving 62 patients. The adverse drug reactions were mainly hemolytic anemia (25, 40.3%), thrombocytopenia (23, 37.1%), and neutropenia (12, 19.4%), which might be accompanied by some typical symptoms. Hemolytic anemia or thrombocytopenia was generally believed to be immune-mediated and often appeared within 10 days, and neutropenia was thought to be related to bone marrow suppression and usually occurred 2 weeks after the initiation of piperacillin/tazobactam. Most patients improved or recovered within a week with treatment or not, and fewer high-quality evidence-based treatments were identified. Conclusion Although part of the patients have clinical symptom, the hematologic adverse drug reactions of piperacillin/tazobactam are easily overlooked or misdiagnosed. Take special caution for patients with prolonged piperacillin/tazobactam treatment or specific disease, and prompt recognition and treatment of the adverse drug reactions are essential and can hasten recovery regardless of the type of side reactions.

Piperacillin-tazobactam induced bicytopenia in low cumulative treatment doses

We present the case of infected wet gangrene of right foot in the setting of poorly controlled type 2 diabetes in a 71-year-old woman. This patient presented with improved infection condition after intravenous piperacillin–tazobactam (PTZ) 2.25 gm every 6 hours treatment and below knee amputation surgery on day 3. However, neutropenia and thrombocytopenia developed on day 13. We consulted a haematologist and performed a series of examinations. However, no significant findings were noted thereafter. PTZ was suspected to be the most likely cause of neutropenia and thrombocytopenia and was hence terminated on day 14 (cumulative dose of PTZ: 126 g) following stabilisation of the infection condition. A transfusion was performed with two units of single donor platelets on day 14 and treated with intravenous dexamethasone 5 mg every 8 hours from day 14 to 16. Her white blood cell and platelet counts increased on day 15 and continued to recover thereafter.

Comparison of Neutropenia Associated with Ceftaroline or Ceftriaxone in Patients Receiving at Least 7 Days of Therapy for Severe Infections

STUDY OBJECTIVE

Ceftarolinefosamil is a cephalosporin with broad clinical utility; however, limited data suggest that prolonged ceftaroline exposure may be associated with neutropenia. The objective was to determine drug and patient factors associated with neutropenia in patients receiving ceftaroline or ceftriaxone for deep-seated infections.

DESIGN

Retrospective, ratio-matched cohort study.

SETTING

Four acute-care hospitals within an urban health care system.

PATIENTS

A total of 176 hospitalized adults who received definitive ceftaroline (44 patients) or ceftriaxone (132 patients) therapy for at least 7 days between January 2013 and April 2017 for any of the following indications: bone and joint infections (BJI), infective endocarditis (IE), or bloodstream infections (BSI).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was development of neutropenia while receiving cephalosporin therapy, defined as an absolute neutrophil count (ANC) <1500 cells/mm3 . Neutropenia severity and patient characteristics were described and compared between the ceftaroline and ceftriaxone groups. The median (interquartile range [IQR]) antibiotic prescription duration was 41 (29-44) days for the ceftaroline group and 40 (28-44) days for the ceftriaxone group (p=0.9). Cephalosporin indications were 112 (64%) BJI, 27 (15%) BSI, 16 (9%) IE, and 21 (12%) multiple infections; ceftaroline was more commonly used in BJI (p=0.03), and ceftriaxone was more commonly used in IE (p=0.01). Neutropenia developed in 16 (9%) patients: 8 (18%) in the ceftaroline group and 8 (6%) in the ceftriaxone group (p=0.03). Median (IQR) onset to neutropenia was 22 (15-28) days, and median (IQR) change in ANC was 2.86 (1.50-4.08) cells/mm3 ; most cases of neutropenia were mild (12 patients [75%]). The median (IQR) time to mild or moderate-severe neutropenia was not significantly different (p=0.68): 22 (14-28) and 22 (21-36) days, respectively. Treatment was discontinued in 4 (25%) patients due to neutropenia. Ceftaroline use was independently associated with neutropenia (adjusted odds ratio 3.2, 95% confidence interval 1.2-10.5) after adjusting for lower body mass index strata (18.5-25 kg/m2 ).

CONCLUSION

Prolonged ceftaroline use was an independent risk factor for developing mild neutropenia. Clinicians should be cognizant of ANC monitoring in scenarios where prolonged ceftaroline courses are prescribed.

Hematologic Adverse Effects of Prolonged Piperacillin-Tazobactam Use in Adults

Objective:

We aimed to find the incidence and risk factors of hematologic adverse effects of piperacillin-tazobactam (TZP).

Materials and Methods:

Adult patients who used TZP for more than 10 days were included in the study.

Results:

The incidence of leukopenia, neutropenia, and eosinophilia in 110 TZP therapy episodes was found to be 16.3%, 10%, and 10%, respectively. Lower Charlson Comorbidity Index score, lower initial leukocyte count, combination of TZP with another antibiotic, and total duration of TZP therapy were found to be independent risk factors for leukopenia, while initial higher eosinophil count (IHEC) and usage of TZP for >20 days were independent risk factors for neutropenia and IHEC and total duration of TZP therapy were independent risk factors for eosinophilia.

Conclusion:

Longer duration of therapy, combination with other antibiotics, younger age with fewer comorbidities, and IHEC could result in hematologic adverse effects in patients treated with TZP. Patients with IHEC may be more prone to allergic reactions, so immunological mechanisms may facilitate the development of hematological adverse effects of TZP.

Assessing the Effect of Piperacillin/Tazobactam on Hematological Parameters in Patients Admitted with Moderate or Severe Foot Infections

INTRODUCTION

Piperacillin/tazobactam is a commonly used antibiotic for the empirical treatment of severe diabetic foot infections. One of the most feared complications of this drug is the development of pancytopenia. The aim of this study was to determine whether the use of piperacillin/tazobactam caused any hematological changes in patients admitted with severe diabetes-related foot infections from a specialist multidisciplinary foot clinic. Specifically, looking at whether it caused anemia, leukopenia, neutropenia, or thrombocytopenia.

METHODS

A 1-year retrospective analysis of patients admitted to a tertiary care center for treatment of diabetes-related foot infection using piperacillin/tazobactam. Hematological indices, urea and electrolytes, and C-reactive protein (CRP) were recorded pretreatment, during treatment, and posttreatment. HbA1c, vitamin B₁₂, folate, thyroid-stimulating hormone, and free thyroxin were also analyzed to exclude any potential confounders as a cause of pancytopenia.

RESULTS

A total of 154 patients were admitted between 1 January 2016 and 31 December 2016 who received piperacillin/tazobactam for severe diabetes-related foot infection. On admission, white cell count and CRP were raised and fell significantly within the first 48 h. Other hematological factors did not change. Five patients developed a mild pancytopenia, of which three were unexplained.

CONCLUSION

In this relatively small cohort, pancytopenia did not occur. As such, piperacillin/tazobactam appeared to have a low risk of adverse hematological outcomes and remains the treatment of choice for severe diabetes-related foot infections.

Neutropenia induced by high-dose intravenous benzylpenicillin in treating neurosyphilis: Does it really matter?

BACKGROUND

Prompt therapy with high-dose intravenous benzylpenicillin for a prolonged period is critical for neurosyphilis patients to avoid irreversible sequelae. However, life-threatening neutropenia has been reported as a complication of prolonged therapy with high doses of benzylpenicillin when treating other diseases. This study aimed to investigate the incidence, presentation, management and prognosis of benzylpenicillin-induced neutropenia in treating neurosyphilis based on a large sample of syphilis patients in Shanghai.

METHODOLOGY/PRINCIPAL FINDINGS

Between 1st January 2013 and 31st December 2015, 1367 patients with neurosyphilis were treated with benzylpenicillin, 578 of whom were eligible for recruitment to this study. Among patients without medical co-morbidities, the total incidence of benzylpenicillin-induced neutropenia and severe neutropenia was 2.42% (95% CI: 1.38-4.13%) and 0.35% (95% CI: 0.06-1.39%), respectively. The treatment duration before onset of neutropenia ranged from 10 to 14 days, with a total cumulative dose of between 240 and 324 megaunits of benzylpenicillin. Neutropenia was accompanied by symptoms of chills and fever (5 patients), fatigue (2 patients), cough (1 patient), sore throat (1 patient), diarrhea (1 patient) and erythematous rash (1 patient). The severity of neutropenia was not associated with age, gender or type of neurosyphilis (p>0.05). Neutropenia, even when severe, was often tolerated and normalized within one week. A more serious neutropenia did not occur when reinstituting benzylpenicillin in patients with mild or moderate neutropenia nor when ceftriaxone was used three months after patients had previously experienced severe neutropenia.

CONCLUSIONS/SIGNIFICANCE

Benzylpenicillin-induced neutropenia was uncommon in our cohort of patients. Continuation of therapy was possible with intensive surveillance for those with mild or moderate neutropenia. For severe neutropenia, it is not essential to aggressively use hematopoietic growth factors or broad-spectrum antibiotics for patients in good physical condition after withdrawing anti-neurosyphilis regimen. We did not see an exacerbation of neutropenia in patients with the readministration of benzylpenicillin.

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.

Understanding chronic neutropenia: life is short

The pathophysiological mechanisms underlying chronic neutropenia are extensive, varying from haematopoietic stem cell disorders resulting in defective neutrophil production, to accelerated apoptosis of neutrophil progenitors or circulating mature neutrophils. While the knowledge concerning genetic defects associated with congenital neutropenia or bone marrow failure is increasing rapidly, the functional role and consequences of these genetic alterations is often not well understood. In addition, there is a large group of diseases, including primary immunodeficiencies and metabolic diseases, in which chronic neutropenia is one of the symptoms, while there is no clear bone marrow pathology or haematopoietic stem cell dysfunction. Altogether, these disease entities illustrate the complexity of normal neutrophil development, the functional role of the (bone marrow) microenvironment and the increased propensity to undergo apoptosis, which is typical for neutrophils. The large variety of disorders associated with chronic neutropenia makes classification almost impossible and possibly not desirable, based on the clinical phenotypes. However, a better understanding of the regulation of normal myeloid differentiation and neutrophil development is of great importance in the diagnostic evaluation of unexplained chronic neutropenia. In this review we propose insights in the pathophysiology of chronic neutropenia in the context of the functional role of key players during normal neutrophil development, neutrophil release and neutrophil survival.

Fever and Reversible Laboratory Abnormalities Associated with Prolonged Use of Piperacillin-Tazobactam in Children

Piperacillin-tazobactam is used frequently in pediatric patients with complicated appendicitis and other intra-abdominal infections. We report 10 pediatric patients who developed a piperacillin-tazobactam-associated adverse reaction characterized by fever, rash, hematologic abnormalities and transaminitis. Physicians should be aware of this entity in patients treated with a prolonged course of piperacillin-tazobactam. Prompt identification can obviate unnecessary diagnostic testing and treatment.

A case of profound neutropenia and agranulocytosis associated with off-label use of ceftaroline

PURPOSE

A case of profound neutropenia and agranulocytosis associated with the off-label use of ceftaroline is reported.

SUMMARY

A 67-year-old Caucasian man arrived at the emergency room with right shoulder pain and weakness that radiated to his right chest, back, and right arm. A review of symptoms was notable for two days of burning with urination associated with decreased urinary output and decreased appetite. Multiple tests revealed the presence of methicillin-resistant Staphylococcus aureus (MRSA) septic arthritis, which was treated with an off-label dosage of ceftaroline (600 mg intravenously every eight hours). At the start of ceftaroline therapy, the patient's baseline absolute neutrophil count (ANC) was 6640 cells/μL and decreased to 816 cells/μL by day 19, eventually falling to 0 cells/μL on day 21 of therapy. Ceftaroline was then discontinued due to the suspicion that the neutropenia was secondary to maturation arrest of the bone marrow. The patient was switched to i.v. daptomycin to finish a six-week course of antibiotics. Interventional radiology placed a drain in the patient's right shoulder during the hospital stay, with symptom improvement. His white blood cell count continued to increase after ceftaroline discontinuation, reaching 6.5×10(3) cells/μL with a differential of 56.6% segmented neutrophils and 28.4% lymphocytes after nine days off of ceftaroline.

CONCLUSION

A 67-year-old man developed profound neutropenia and agranulocytosis after three weeks of high-dose ceftaroline therapy for the treatment of MRSA septic arthritis. His neutropenia resolved after ceftaroline discontinuation and treatment with an alternative antibiotic.

Ceftaroline - a cause for neutropenia

WHAT IS KNOWN AND OBJECTIVE

The US Food and Drug Administration approved ceftaroline in 2010 for the treatment of community-acquired pneumonia and skin and soft-tissue infections. The most common adverse reactions are diarrhoea, nausea and rash. To present the first case of neutropenia directly related to ceftaroline.

CASE SUMMARY

A 90-year-old female was given ceftaroline for treatment of a pneumonia complicated by methicillin-resistant Staphylococcus aureus bacteraemia and possible vertebral osteomyelitis. After 25 days of ceftaroline, she developed neutropenia. Ceftaroline was discontinued and her white blood cell count returned to normal within one week.

WHAT IS NEW AND CONCLUSION

Although neutropenia is a potential cephalosporin class effect, we present the first case of neutropenia directly related to ceftaroline. Agranulocytosis and neutropenia are rare, yet potentially life-threatening adverse effects of cephalosporins. Healthcare providers should be aware of the potential for ceftaroline to cause neutropenia, particularly in patients treated for greater than two weeks.

Piperacillin/tazobactam induced thrombocytopaenia--a delayed response

A 48-year-old lady who presented with sepsis secondary to a pelvi-ureteric junction obstruction was treated with an extended course of piperacillin/tazobactam. Four days after completing the course she developed thrombocytopaenia. Intravenous immunoglobulin was required to bring her platelet count back to normal. In the absence of other causes the authors believe that a delayed reaction to piperacillin/tazobactam was the cause of her thrombocytopaenia.

Piperacillin and vancomycin induced severe thrombocytopenia in a hospitalized patient

In hospitalized patients with complex medical problems on numerous drugs, thrombocytopenia may have a multiple confounding etiology. Keeping this in mind, it is of utmost importance to monitor the platelet count regularly during hospitalization and on subsequent follow-up visits, even after the most probable etiology has been identified/most likely causative drug has been withdrawn. Isolated thrombocytopenia with no evidence of microangiopathic hemolysis on the peripheral blood smear in an acutely ill hospitalized patient implicated sepsis, disseminated intravascular coagulation and drugs as the most probable causes. Our patient represents an uncommon case of antibiotic-induced severe immune thrombocytopenia, as he developed both vancomycin-dependent and piperacillin-dependent antibodies, while being treated for cellulitis (vancomycin-specific antibodies of the IgG isotype, and both IgG and IgM antibodies specific for piperacillin were identified in laboratory testing). Vancomycin was stopped before the reports were available. Following this, the patient's platelet count showed a transient upward trend, but then the thrombocytopenia worsened drastically reaching a nadir of 10,000/µL. The platelet count returned to normal only after piperacillin/tazobactam was stopped after a week, thus establishing it as the cause of the more severe thrombocytopenia, which occurred later on; this was subsequently confirmed by the laboratory results. Vancomycin is an established cause of drug-induced immune thrombocytopenias, especially in acutely ill, hospitalized or elderly patients, whereas incidents of piperacillin/tazobactam-induced immune thrombocytopenia are uncommon. In case clinical suspicion is high, workup should include immunoprecipitation and flow cytometry studies to confirm antiplatelet antibodies.

Piperacillin/tazobactam Induced Myelosuppression

Neutropenia, secondary to immune destruction or maturation arrest, is the most commonly described adverse haematological effect of beta-lactam antibiotics. We describe a case of reversible pancytopenia, with evidence of hypocellular marrow, after a prolonged course of piperacillin/tazobactam for 26 days.

Hepatotoxicity associated with long- versus short-course HIV-prophylactic nevirapine use: a systematic review and meta-analysis from the Research on Adverse Drug events And Reports (RADAR) project

BACKGROUND AND OBJECTIVE

The antiretroviral nevirapine can cause severe hepatotoxicity when used 'off-label' for preventing mother-to-child HIV transmission (PMTCT), newborn post-exposure prophylaxis and for pre- and post-exposure prophylaxis among non-HIV-infected individuals. We describe the incidence of hepatotoxicity with short- versus long-course nevirapine-containing regimens in these groups.

METHODS

We reviewed hepatotoxicity cases among non-HIV-infected individuals and HIV-infected pregnant women and their offspring receiving short- (or=5 days) nevirapine prophylaxis. Sources included adverse event reports from pharmaceutical manufacturers and the US FDA, reports from peer-reviewed journals/scientific meetings and the Research on Adverse Drug events And Reports (RADAR) project. Hepatotoxicity was scored using the AIDS Clinical Trial Group criteria.

RESULTS

Toxicity data for 8216 patients treated with nevirapine-containing regimens were reviewed. Among 402 non-HIV-infected individuals receiving short- (n=251) or long-course (n=151) nevirapine, rates of grade 1-2 hepatotoxicity were 1.99% versus 5.30%, respectively, and rates of grade 3-4 hepatotoxicity were 0.00% versus 13.25%, respectively (p<0.001 for both comparisons). Among 4740 HIV-infected pregnant women receiving short- (n=3031) versus long-course (n=1709) nevirapine, rates of grade 1-2 hepatotoxicity were 0.62% and 7.04%, respectively, and rates of grade 3-4 hepatotoxicity were 0.23% versus 4.39%, respectively (p<0.001 for both comparisons). The rates of grade 3-4 hepatotoxicity among 3074 neonates of nevirapine-exposed HIV-infected pregnant women were 0.8% for those receiving short-course (n=2801) versus 1.1% for those receiving long-course (n=273) therapy (p<0.72).

CONCLUSIONS

Therapy duration appears to significantly predict nevirapine hepatotoxicity. Short-course nevirapine for HIV prophylaxis is associated with fewer hepatotoxic reactions for non-HIV-infected individuals or pregnant HIV-infected women and their offspring, but administration of prophylactic nevirapine for >or=2 weeks appears to be associated with high rates of hepatotoxicity among non-HIV-infected individuals and HIV-infected pregnant mothers. When full highly active antiretroviral therapy (HAART) regimens are not available, single-dose nevirapine plus short-course nucleoside reverse transcriptase inhibitors to decrease the development of HIV viral resistance is an essential therapeutic option for PMTCT and these data support the safety of single-dose nevirapine in this setting.

Cephalosporin-induced leukopenia following rechallenge with cefoxitin

OBJECTIVE

To describe a case of cefazolin-induced leukopenia in a critically ill patient who developed this adverse reaction upon rechallenge with cefoxitin.

CASE SUMMARY

A 22-year-old male was admitted after a motor vehicle crash. beta-Lactam therapy was initiated with vancomycin, cefepime, and metronidazole and, upon identification of methicillin-sensitive Staphylococcus aureus bacteremia 4 days later, therapy was narrowed to cefazolin 1 g every 12 hours. The dose was adjusted to 1 g every 12 hours during continuous venovenous hemodialysis. Imipenem was given for 2 days, resulting in a total of 18 days of beta-lactam treatment, at which time he developed significant leukopenia (white blood cell [WBC] count 0.9 x 10(3)/microL). Antimicrobial treatment was changed to tigecycline and continued for suspected pleural space infection. The patient's WBC count recovered within 4 days after the change in therapy. He was taken to surgery 8 days after cefazolin was discontinued and received perioperative prophylaxis with cefoxitin (total dose 3 g). Subsequently, the patient again became severely leukopenic (WBC count 2.4 x 10(3)/microL). Within a week after surgery, the patient developed septic shock secondary to multidrug-resistant Escherichia coli bacteremia and died.

DISCUSSION

beta-Lactam-induced leukopenia is a rare but well-described adverse drug reaction. It is a cumulative dose-dependent phenomenon reported to occur most often after 2 weeks of therapy. The mechanism of leukopenia is thought to be secondary to either an immune-mediated response or direct bone marrow toxicity. Rechallenge with a different beta-lactam antibiotic has not been shown to consistently cause recurrent leukopenia. The case described here suggests an immune-related mechanism for the development of leukopenia. Use of the Naranjo probability scale determined the association between cephalosporin use and leukopenia to be probable.

CONCLUSIONS

Cefazolin was a probable cause of this patient's leukopenia. It is important for clinicians to recognize beta-lactam-induced leukopenia and maybe recommend use of a drug from a different antibiotic class if continued treatment is indicated.