Intravenous pentamidine is effective as second line Pneumocystis pneumonia prophylaxis in pediatric oncology patients

Healthcare utilization disparities among children with high-risk neuroblastoma treated on Children's Oncology Group clinical trials

INTRODUCTION

Disparities in relapse and survival from high-risk neuroblastoma (HRNBL) persist among children from historically marginalized groups even in highly standardized clinical trial settings. Research in other cancers has identified differential treatment toxicity as one potential underlying mechanism. Whether racial and ethnic disparities in treatment-associated toxicity exist in HRNBL is poorly understood.

METHODS

This is a retrospective study utilizing a previously assembled merged cohort of children with HRNBL on Children's Oncology Group (COG) post-consolidation immunotherapy trials ANBL0032 and ANBL0931 at Pediatric Health Information System (PHIS) centers from 2005 to 2014. Race and ethnicity were categorized to reflect historically marginalized populations as Hispanic, non-Hispanic Black (NHB), non-Hispanic other (NHO), and non-Hispanic White (NHW). Associations between race-ethnicity and intensive care unit (ICU)-level care utilization as a proxy for treatment-associated toxicity were examined with log binomial regression and summarized as risk ratio (RR) and corresponding 95% confidence interval (CI).

RESULTS

The analytic cohort included 370 children. Overall, 88 (23.8%) patients required ICU-level care for a median of 3.0 days (interquartile range [IQR]: 1.0-6.5 days). Hispanic children had nearly three times the risk of ICU-level care (RR 3.1, 95% CI: 2.1-4.5; fully adjusted RR [aRR] 2.5, 95% CI: 1.6-3.7) compared to NHW children and the highest percentage of children requiring cardiovascular-driven ICU-level care.

CONCLUSION

Children of Hispanic ethnicity with HRNBL receiving clinical trial-delivered therapy were more likely to experience ICU-level care compared to NHW children. These data suggest that further investigation of treatment-related toxicity as a modifiable mechanism underlying outcome disparities is warranted.

A retrospective study of intravenous pentamidine for Pneumocystis jirovecii pneumonia prophylaxis in adult patients with hematologic malignancies-its utility during respiratory virus pandemics

OBJECTIVES

In hematology, prophylaxis for Pneumocystis jirovecii pneumonia (PCP) is recommended for patients undergoing hematopoietic stem cell transplantation and in selected categories of intensive chemotherapy for hematologic malignancies. Trimethoprim-sulfamethoxazole (TMP-SMX) is the recommended first-line agent; however, its use is not straightforward. Inhaled pentamidine is the recommended second-line agent; however, aerosolized medications were discouraged during respiratory virus outbreaks, especially during the COVID-19 pandemic, in view of potential contamination risks. Intravenous (IV) pentamidine is a potential alternative agent. We evaluated the effectiveness and tolerability of IV pentamidine use for PCP prophylaxis in adult allogeneic hematopoietic stem cell transplantation recipients and patients with hematologic malignancies during COVID-19.

RESULTS

A total of 202 unique patients who received 239 courses of IV pentamidine, with a median of three doses received (1-29). The largest group of the patients (49.5%) who received IV pentamidine were undergoing or had received a hematopoietic stem cell transplant. The most common reason for not using TMP-SMX prophylaxis was cytopenia (34.7%). We have no patients who had breakthrough PCP infection while on IV pentamidine. None of the patients developed an infusion reaction or experienced adverse effects from IV pentamidine.

CONCLUSIONS

Pentamidine administered IV monthly is safe and effective.

Incidence of Pneumocystis pneumonia in Immunocompromised Patients without Human Immunodeficiency Virus with Intravenous Pentamidine Prophylaxis: A Systematic Review and Meta-Analysis

Background: Trimethoprim-sulfamethoxazole (TMP-SMX) is a first-line Pneumocystis pneumonia pneumonia) (PCP) prophylaxis agent, but monthly intravenous pentamidine (IVP) is used in human immunodeficiency virus (HIV)-uninfected immunocompromised hosts because IVP is not associated with cytopenia and delayed engraftment. Method: We performed a systematic review and meta-analysis to estimate breakthrough PCP incidence and adverse reactions in HIV-uninfected immunocompromised patients receiving IVP. MEDLINE, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov were searched from their inception until 15 December 2022. Results: The pooled incidence of breakthrough PCP with IVP was 0.7% (95% CI, 0.3–1.4%, 16 studies, 3025 patients) and was similar when used as first-line prophylaxis (0.5%; 95% CI, 0.2–1.4%, 7 studies, 752 patients). The pooled incidence of adverse reactions was 11.3% (95% CI, 6.7–18.6%, 14 studies, 2068 patients). The pooled adverse event-related discontinuation was 3.7% (95% CI, 1.8–7.3%, 11 studies, 1802 patients), but was lower in patients receiving IVP monthly (2.0%; 95% CI 0.7–5.7%, 7 studies, 1182 patients). Conclusion: Monthly IVP is an appropriate second-line agent for PCP prophylaxis in certain non-HIV immunocompromised hosts, especially in patients with hematologic malignancies and hematopoietic stem cell transplant recipients. Using IVP for PCP prophylaxis as an alternative to oral TMP-SMX while patients are unable to tolerate enteral medication administration is feasible.

Pneumocystis jirovecii Pneumonia Prophylaxis with Intravenous Pentamidine in Adult Allogeneic Hematopoietic Stem Cell Transplant Patients

The purpose of this single-center retrospective case series was to evaluate the efficacy and safety of 300-mg once-monthly intravenous (IV) pentamidine prophylaxis in 702 adult allogeneic hematopoietic stem cell transplant (HSCT) patients. We observed no cases of Pneumocystis jirovecii pneumonia (PJP) following IV pentamidine administration. Breakthrough Nocardia and Toxoplasma infections were observed in 7 (1%) and 5 (0.7%) patients, respectively. The most commonly reported adverse event was nausea. Monthly IV pentamidine is a reasonable alternative to trimethoprim-sulfamethoxazole (TMP-SMX).

Pneumocystis jirovecii Pneumonia in Children with Hematological Malignancies: Diagnosis and Approaches to Management

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection that mostly affects children with suppressed cellular immunity. PJP was the most common cause of infectious death in children with acute lymphoblastic leukemia prior to the inclusion of cotrimoxazole prophylaxis as part of the standard medical care in the late 1980s. Children with acute leukemia, lymphomas, and those undergoing hematopoietic stem cell transplantation, especially allogeneic transplantation, are also at high risk of PJP. Persistent lymphopenia, graft versus host disease, poor immune reconstitution, and lengthy use of corticosteroids are significant risk factors for PJP. Active infection may be due to reactivation of latent infection or recent acquisition from environmental exposure. Intense hypoxemia and impaired diffusing capacity of the lungs are hallmarks of PJP, while computerized tomography of the lungs is the diagnostic technique of choice. Immunofluorescence testing with monoclonal antibodies followed by fluorescent microscopy and polymerase chain reaction testing of respiratory specimens have emerged as the best diagnostic methods. Measurement of (1-3)-β-D-glucan in the serum has a high negative predictive value in ruling out PJP. Oral cotrimoxazole is effective for prophylaxis, but in intolerant patients, intravenous and aerosolized pentamidine, dapsone, and atovaquone are effective alternatives. Ιntravenous cotrimoxazole is the treatment of choice, but PJP has a high mortality even with appropriate therapy.

Impact of prophylaxis choice on risk of pneumocystis pneumonia in children with cancer: A case-control study

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a life-threatening opportunistic infection. Prophylaxis is recommended for patients with malignancies and trimethoprim-sulfamethoxazole (TMP-SMX) is the recommended first-line agent. Many paediatric patients receive second-line agents due to perceived adverse reactions from TMP-SMX.

OBJECTIVE

The objective of the study is to determine the risk of PJP in patients receiving TMP-SMX vs. second-line medications for prophylaxis.

METHODS

We conducted a retrospective, single centre, case-control study of paediatric oncology patients. Cases included children diagnosed with PJP by microscopy between 2000 and 2018 while being treated for a malignancy. Controls were matched by age, oncologic diagnosis, treatment protocol, phase of treatment and oncologic diagnosis date. For each case, up to 5 controls were randomly selected. The index date was the date of the PJP diagnosis for cases and the equivalent dummy date for controls.

RESULTS

Eleven cases with PJP were identified and matched with 50 controls. Six (55%) cases and 42 (84%) controls were on prophylaxis with TMP-SMX. The remaining patients received inhaled pentamidine (3 cases, 4 controls), dapsone (2 cases, 3 controls), or atovaquone (1 control). Myelosuppression was the most common reason to stop TMP-SMX. Cases with PJP were less likely to have been taking TMP-SMX in the 3 months before diagnosis when compared with controls (odds ratio: 0.15, 95% confidence interval: 0.01-0.97, p = 0.02).

CONCLUSION

TMP-SMX prophylaxis was associated with a lower risk of developing PJP compared with second-line treatments. Although alternate agents may be required in certain situations, efforts should be made to rechallenge with TMP-SMX when possible.

Trimethoprim-Sulfamethoxazole Associated Drug-Induced Liver Injury in Pediatrics: A Systematic Review

BACKGROUND

Drug-induced liver injury (DILI) is a rare but known adverse event associated with trimethoprim-sulfamethoxazole (TMP-SMX) in adults. No studies to date have looked at the risk of this association in children. We systematically reviewed the evidence for a potential association between TMP-SMX and DILI in the pediatric population.

METHODS

PubMed, Medline, Embase, Cochrane Database of Systematic Reviews, Scopus and Web of Science was searched using a combination of terms to identify reports of TMP-SMX exposure, liver injury and pediatrics (≤18 years old). We included any studies with hepatic adverse events occurring after exposure to TMP-SMX. Bibliographies were reviewed for additional relevant references. The Narajno scale was used to assess causality in case studies.

RESULTS

A total of 22 studies were identified: 3 randomized trials, 1 prospective observational study, 8 retrospective observational studies and 10 case reports. Among the randomized trials and prospective studies, only mild, transient hepatic function abnormalities were reported. Retrospective observational studies reported 1 fatal DILI and statistically significant increased odds of DILI with TMP-SMX use compared with nonuse. Among the 10 case reports, severe liver outcomes and mild hepatic function abnormalities were both reported. Naranjo scores suggested reported hepatic adverse events were probably because of exposure in 5, possible in 4, and doubtful in 1 case report.

CONCLUSIONS

Evidence regarding DILI associated with TMP-SMX exposure in pediatrics is limited. Observational population studies show mild hepatic abnormalities. Case reports suggest more severe manifestations of DILI. Additional studies may reveal the association between TMP-SMX and DILI in pediatrics.

Effectiveness and tolerability of intravenous pentamidine for Pneumocystis carinii pneumonia prophylaxis in adult hematopoietic stem cell transplant patients: a retrospective study

BACKGROUND

Pneumocystis carinii pneumonia (PCP) prophylaxis is recommended after hematopoietic stem cell transplantation (HSCT). In patients who are unable to take first-line prophylaxis, trimethoprim/sulfamethoxazole, aerosolized pentamidine is recommended. This drug may not, however, be available at all institutions, and its administration requires special techniques. Therefore, intravenous pentamidine (IVP) has been used in adult patients as an alternative, despite limited data. We evaluated the effectiveness and tolerability of IVP for PCP prophylaxis in adult patients who had undergone HSCT.

METHODS

A single-center retrospective study was conducted of adult patients who had undergone allogenic or autologous HSCT between January 2014 and September 2018 and had received at least three doses of IVP for PCP prophylaxis. The IVP dose was 4 mg/kg administered monthly. Data on PCP infection and adverse reactions were collected from both patients' electronic medical records and the pharmacy adverse drug reactions documentation system. Patients were followed from the start of IVP up to 6 months after discontinuation of therapy. A confirmed PCP infection was defined as radiographic evidence of PCP and positive staining of a respiratory specimen. Descriptive statistics were used to analyze the study outcomes.

RESULTS

During the study period, 187 patients were included. The median age was 36.4 years (range, 18-64), 58% were male, and 122 (65%) had received allogeneic HSCT while the remainder autologous HSCT. The median number of IVP doses administered per patient was 5 (range, 3-29). During the study period, none of the patients had evidence of confirmed PCP infection. However; there were two cases with high clinical suspicion of PCP infection (i.e. required anti-pneumocystis therapy) and one reported case of central nervous system toxoplasmosis while receiving IVP for PCP prophylaxis. Only one case of nausea associated with IVP administration was reported.

CONCLUSIONS

In a cohort of adult patients with HSCT who received IVP for PCP prophylaxis, there was no evidence of confirmed PCP infection, and the treatment appeared to be well tolerated. Prospective studies should be conducted to confirm the efficacy and tolerability of IVP.

How to Treat Cytomegalovirus-induced Hemophagocytic Lymphohistiocytosis in a Child With Leukemia

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by a hyperinflammatory state due to an aberrant activation of the immune cells. It can be familial or secondary to malignancy, autoimmune or metabolic diseases. Most HLH cases are triggered by infection. Histiocyte society suggested HLH-2004 protocol for diagnosis and treatment of both forms. Here, we present a three-year-old girl with B-cell acute lymphoblastic leukemia who developed HLH secondary to cytomegalovirus infection during maintenance therapy. She was successfully treated without needing full HLH protocol therapy. We discuss modified therapy for this specific group of HLH, summarizing 5 other similar cases in the literature.

Tolerability of Aerosolized Versus Intravenous Pentamidine for Pneumocystis jirovecii Pneumonia Prophylaxis in Immunosuppressed Pediatric, Adolescent, and Young Adult Patients

OBJECTIVES

Pentamidine is an antifungal that is used alternatively to sulfamethoxazole-trimethoprim for the prophylaxis and treatment of Pneumocystis jirovecii pneumonia (PJP). The primary objective of this study was to assess the tolerability of aerosolized versus intravenous pentamidine for PJP prophylaxis in pediatric, adolescent, and young adult immunosuppressed patients. Secondary objectives included comparing pentamidine formulation reaction to dosing frequency and diagnosis.

METHODS

This retrospective chart review used electronic medical record (EMR) data from patients at a tertiary care pediatric teaching institution from January 1, 2014, to January 1, 2017. Information used from the EMR included pentamidine dosing, ordering, and laboratory values. Inclusion criteria consisted of patients with a cancer diagnosis, hematopoietic stem cell transplant (HSCT) recipients, and renal transplant recipients who received pentamidine for PJP prophylaxis.

RESULTS

Ninety-six patients met inclusion criteria, of which 31 received aerosolized pentamidine. Ten of the 96 patients experienced a drug-related reaction to either aerosolized or intravenous pentamidine (p = 0.134). Nine of 10 patients who experienced a reaction received intravenous pentamidine versus 1 patient who received aerosolized pentamidine (p = 0.132). In those patients who reacted to pentamidine there was a higher incidence of reactions after subsequent administration (p = 0.039) and in patients with a blood cancer diagnosis (p = 0.042).

CONCLUSIONS

Data suggest that patients who receive aerosolized pentamidine may tolerate therapy better compared to intravenous administration. Additional studies involving larger numbers of pediatric, adolescent, and young adult patients are needed for stronger statistically significant clinical differences in tolerability of aerosolized versus intravenous pentamidine.

Pentamidine for Prophylaxis against Pneumocystis jirovecii Pneumonia in Pediatric Oncology Patients Receiving Immunosuppressive Chemotherapy

Pneumocystis jirovecii pneumonia is a life-threatening opportunistic infection in children receiving immunosuppressive chemotherapy. Without prophylaxis, up to 25% of pediatric oncology patients receiving chemotherapy will develop Pneumocystis jirovecii pneumonia. Trimethoprim-sulfamethoxazole is the preferred agent for prophylaxis against Pneumocystis jirovecii pneumonia. Pentamidine may be an acceptable alternative for pediatric patients unable to tolerate trimethoprim-sulfamethoxazole. A retrospective review was conducted of pediatric oncology patients who received ≥1 dose of pentamidine for Pneumocystis jirovecii pneumonia prophylaxis between January 2007 and August 2014. Electronic medical records were reviewed to determine the incidence of breakthrough Pneumocystis jirovecii pneumonia or discontinuation of pentamidine associated with adverse events. A total of 754 patients received pentamidine prophylaxis during the period. There were no cases of probable or proven Pneumocystis pneumonia, and 4 cases (0.5%) of possible Pneumocystis pneumonia. The incidence of possible breakthrough Pneumocystis pneumonia was not significantly different between subgroups based on age (<12 months [1.7%] versus ≥12 months [0.4%], P = 0.3), route of administration (aerosolized [0%] versus intravenous [1.0%], P = 0.2), or hematopoietic stem cell transplant status (transplant [0.4%] versus no transplant [0.8%], P = 0.6). Pentamidine was discontinued due to an adverse drug event in 23 children (3.1%), more frequently for aerosolized than for intravenous administration (7.6% versus 2.2%, respectively, P = 0.004). Intravenous or inhaled pentamidine may be a safe and effective second-line alternative for prophylaxis against Pneumocystis jirovecii pneumonia in children with cancer receiving immunosuppressive chemotherapy or hematopoietic stem cell transplantation.

The use of intravenous pentamidine for the prophylaxis of Pneumocystis pneumonia in pediatric patients

Pneumocystis jiroveci pneumonia was common in the immunocompromised host before the widespread use of prophylaxis. When trimethoprim-sulfamethoxazole is not tolerated, prophylaxis with intravenous pentamidine (IVP) may be initiated. We performed a retrospective analysis of all pediatric patients who received IVP regarding efficacy, safety, and reason for initiation. Of 106 patients included in our analysis, one patient tested positive for Pneumocystis DNA. Adverse events were reported in 18% of IVP courses, and main reason for initiation was cytopenia (59%). We found IVP to be effective and safe, and recommend the use of IVP in pediatric patients in whom first-line prophylaxis is contraindicated.

Guidelines for the Prophylaxis of Pneumocystis jirovecii Pneumonia (PJP) in Children With Solid Tumors

Although it is well-established that children undergoing allogeneic stem cell transplants and treatment for leukemia should be offered prophylaxis against Pneumocystis jirovecii pneumonia, the risk for children with solid malignancies is less certain. This guideline has been developed with the aim of standardizing practice and optimizing the benefit versus risk of prophylactic medication in this group of patients. P. jirovecii pneumonia has a high mortality rate even with prompt antimicrobial treatment. Since prophylaxis with co-trimoxazole is safe, effective, and inexpensive, we suggest that all children with malignancies undergoing immunosuppressive therapy are offered prophylaxis unless there are clear contraindications.

Safety and Effectiveness of Intravenous Pentamidine for Prophylaxis of Pneumocystis jirovecii Pneumonia in Pediatric Hematology/Oncology Patients

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection that can lead to significant morbidity and mortality in immunocompromised pediatric hematology/oncology patients. Trimethoprim/sulfamethoxazole is the gold standard for prophylaxis. Intravenous (IV) pentamidine is the preferred second-line agent for PCP prophylaxis at our institution and is used first-line under certain circumstances. The purpose of this study is to evaluate the effectiveness and safety of IV pentamidine for PCP prophylaxis in pediatric hematology/oncology patients.

MATERIALS AND METHODS

A retrospective analysis of pediatric hematology/oncology patients (N=121) who received ≥1 dose of IV pentamidine between January 2009 and July 2014 was conducted. Electronic health records were reviewed to determine baseline characteristics, rate of breakthrough PCP infection, characteristics of IV pentamidine use, and adverse events. The follow-up period was 6 months after the last reported IV pentamidine dose or the last recorded clinic visit/hospital admission.

RESULTS

No patients developed PCP during the entirety of their IV pentamidine course or during the follow-up period. Nineteen patients (16%) experienced adverse events and 5 of the 19 patients required discontinuation of IV pentamidine.

CONCLUSIONS

IV pentamidine is a safe, tolerable, and effective agent for PCP prophylaxis in pediatric hematology/oncology patients and may be considered a reasonable therapeutic alternative when trimethoprim/sulfamethoxazole cannot be used for PCP prophylaxis.

ECIL guidelines for preventing Pneumocystis jirovecii pneumonia in patients with haematological malignancies and stem cell transplant recipients

The 5th European Conference on Infections in Leukaemia (ECIL-5) meeting aimed to establish evidence-based recommendations for the prophylaxis of Pneumocystis jirovecii pneumonia (PCP) in non-HIV-infected patients with an underlying haematological condition, including allogeneic HSCT recipients. Recommendations were based on the grading system of the IDSA. Trimethoprim/sulfamethoxazole given 2-3 times weekly is the drug of choice for the primary prophylaxis of PCP in adults ( A-II: ) and children ( A-I: ) and should be given during the entire period at risk. Recent data indicate that children may benefit equally from a once-weekly regimen ( B-II: ). All other drugs, including pentamidine, atovaquone and dapsone, are considered second-line alternatives when trimethoprim/sulfamethoxazole is poorly tolerated or contraindicated. The main indications of PCP prophylaxis are ALL, allogeneic HSCT, treatment with alemtuzumab, fludarabine/cyclophosphamide/rituximab combinations, >4 weeks of treatment with corticosteroids and well-defined primary immune deficiencies in children. Additional indications are proposed depending on the treatment regimen.

Pneumocystis jirovecii pneumonia: still a concern in patients with haematological malignancies and stem cell transplant recipients

The risk of patients with ALL and recipients of an allogeneic HSCT developing Pneumocystis jirovecii pneumonia is sufficiently high to warrant guidelines for the laboratory diagnosis, prevention and treatment of the disease. In this issue, the European Conference on Infections in Leukemia (ECIL) presents its recommendations in three companion papers.

Is Aerosolized Pentamidine for Pneumocystis Pneumonia Prophylaxis in Renal Transplant Recipients Not as Safe as We Might Think?

Outbreaks ofPneumocystispneumonia have been described in renal transplant recipients. Aerosolized pentamidine is frequently used for prophylaxis in this setting. We report our experience with aerosolized pentamidine use in 56 renal transplant recipients. We found high rates of adverse reactions in patients with chronic respiratory disease.

Central venous catheter-related blood stream infection with pyomyositis due to Stenotrophomonas maltophilia after allogeneic bone marrow transplantation in a patient with aplastic anemia

Stenotrophomonas maltophilia causes pneumonia and CVC-CRBSI in HSCT. However, there are few reports of pyomyositis due to S. maltophilia. We report a patient with CRBSI and pyomyositis due to S. maltophilia after allogeneic HSCT who was successfully treated by removing the CVC and antibiotics without surgical drainage. Removing the CVC and the combined antibiotics without preventing the neutrophil engraftment could avoid surgical drainage in pyomyositis due to S. maltophilia when detected in an early stage.

Safe and Effective Prophylaxis with Bimonthly Intravenous Pentamidine in the Pediatric Hematopoietic Stem Cell Transplant Population

BACKGROUND

Without prophylaxis, Pneumocystis jiroveci pneumonia (PCP) develops in 5%-15% of pediatric hematopoietic stem cell transplant (HCT) patients with mortality above 50%. Trimethoprim-sulfamethoxazole is a standard PCP prophylaxis; pentamidine is frequently used as second-line prophylaxis because of trimethoprim-sulfamethoxazole's potential for cytopenias. Monthly intravenous (IV) pentamidine has variable efficacy with PCP infection rates of 0%-10% in pediatric patients, and higher breakthrough rates in those younger than 2 years. We hypothesized that bimonthly (twice monthly) pentamidine might have equivalent safety and improved efficacy; therefore, we conducted a retrospective analysis of bimonthly pentamidine PCP prophylaxis.

METHODS

We retrospectively reviewed records of all pediatric HCT patients who received bimonthly IV pentamidine between December 2006 and June 2013, and collected data regarding demographics, clinical course, prophylaxis rationale, laboratory values and adverse events.

RESULTS

Between December 2006 and June 2013, 111 pediatric HCT patients received bimonthly IV pentamidine (574 doses, 8758 patient-days); 31 patients were younger than 2 years at initiation. In the majority (53% of courses), pentamidine was initiated because of cytopenias. Fourteen patients (12.6% of patients, 2.4% of doses) experienced a side-effect prompting discontinuation, including 3 patients with infusion-related hypotension/anaphylaxis and 3 with acute pancreatic dysfunction. No patients [0% (95% confidence interval: 0-3.2)] developed PCP during or after bimonthly IV pentamidine prophylaxis.

CONCLUSIONS

Bimonthly IV pentamidine for PCP prophylaxis in the HCT pediatric population has comparable safety to monthly IV pentamidine and was highly effective, including in the very young. Bimonthly IV pentamidine should be considered in pediatric patients as second-line PCP prophylaxis.

The incidence, mortality and timing of Pneumocystis jiroveci pneumonia after hematopoietic cell transplantation: a CIBMTR analysis

Pneumocystis jiroveci pneumonia (PJP) is associated with high morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Little is known about PJP infections after HSCT because of the rarity of disease given routine prophylaxis. We report the results of a Center for International Blood and Marrow Transplant Research study evaluating the incidence, timing, prophylaxis agents, risk factors and mortality of PJP after autologous (auto) and allogeneic (allo) HSCT. Between 1995 and 2005, 0.63% allo recipients and 0.28% auto recipients of first HSCT developed PJP. Cases occurred as early as 30 days to beyond a year after allo HSCT. A nested case cohort analysis with supplemental data (n=68 allo cases, n=111 allo controls) revealed that risk factors for PJP infection included lymphopenia and mismatch after HSCT. After allo or auto HSCT, overall survival was significantly poorer among cases vs controls (P=0.0004). After controlling for significant variables, the proportional hazards model revealed that PJP cases were 6.87 times more likely to die vs matched controls (P<0.0001). We conclude PJP infection is rare after HSCT but is associated with high mortality. Factors associated with GVHD and with poor immune reconstitution are among the risk factors for PJP and suggest that protracted prophylaxis for PJP in high-risk HSCT recipients may improve outcomes.

Consensus guidelines for diagnosis, prophylaxis and management of Pneumocystis jirovecii pneumonia in patients with haematological and solid malignancies, 2014

Pneumocystis jirovecii infection (PJP) is a common cause of pneumonia in patients with cancer-related immunosuppression. There are well-defined patients who are at risk of PJP due to the status of their underlying malignancy, treatment-related immunosuppression and/or concomitant use of corticosteroids. Prophylaxis is highly effective and should be given to all patients at moderate to high risk of PJP. Trimethoprim-sulfamethoxazole is the drug of choice for prophylaxis and treatment, although several alternative agents are available.

Intravenous pentamidine for Pneumocystis carinii/jiroveci pneumonia prophylaxis in pediatric transplant patients

SMX/TMP is the current gold standard for prophylaxis against PCP in immunocompromised pediatric patients. Currently, there are several second-line options for prophylaxis but many, including intravenous (IV) pentamidine, have not been reported to be as effective or as safe as SMX/TMP in the pediatric transplant population. This study is to determine the efficacy and safety of IV pentamidine in preventing PCP in pediatric transplant patients. A retrospective chart review was conducted to evaluate all transplant patients that received at least one dose of IV pentamidine from January 2010 to July 2013. The primary outcome, IV pentamidine efficacy, was evaluated by the incidence of PCP diagnosis for 28 days after the last dose of IV pentamidine if patient was transitioned to another agent for PCP prophylaxis. Patients on IV pentamidine for entire course of PCP prophylaxis were followed at least six months after discontinuation of IV pentamidine. The safety of IV pentamidine was assessed by the incidence of adverse events leading to pentamidine discontinuation. All data were analyzed using descriptive statistics. All transplant patients at CCHMC who had received IV pentamidine were reviewed, and 333 patients met inclusion criteria. The overall incidence of PCP was found to be 0.3% for pediatric transplant patients on pentamidine. Pentamidine was found to be safe, and the incidence of adverse events leading to discontinuation was 6% with the most common reason being tachycardia 2.1%. IV pentamidine is safe and effective as PCP prophylaxis in pediatric transplant patients with a PCP breakthrough rate of 0.3% (1 of 333 patients), and only 20 adverse events led to discontinuation. We recommend that IV pentamidine be considered as a second-line option in pediatric transplant patients who cannot tolerate SMX/TMP.

Neutropenia Precautions for Children Receiving Chemotherapy or Stem Cell Transplantation for Cancer

Infections in children and adolescents with cancer are a significant cause of morbidity and mortality, especially in those receiving chemotherapy who are neutropenic and/or immunocompromised. The aim of this article is to review existing evidence in order to provide a practice recommendation to prevent or minimize infections in neutropenic and/or immunocompromised patients receiving chemotherapy and/or stem cell transplant. Systematic reviews were undertaken and research was graded according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. A variety of interventions are implemented to reduce infections in the neutropenic and/or immunocompromised population; however, few are supported by research evidence. Existing literature should continue to be reviewed to further identify interventions that can influence positive patient outcomes and provide opportunities for individuals in the medical field to work together to improve clinical care.

Efficacy and tolerability of intravenous pentamidine isethionate for Pneumocystis jiroveci prophylaxis in a pediatric oncology population

Cancer therapy routinely requires Pneumocystis jiroveci prophylaxis. In those intolerant of trimethoprim/sulfamethoxazole, aerosolized pentamidine is convenient and effective. Intravenous pentamidine is often substituted in young children but its efficacy remains controversial. In this retrospective study of a large pediatric oncology cohort, we confirm intravenous pentamidine to be effective and well-tolerated as second-line prophylaxis across all ages.

Intravenous pentamidine is safe and effective as primary pneumocystis pneumonia prophylaxis in children and adolescents undergoing hematopoietic stem cell transplantation

BACKGROUND

Pneumocystis carinii pneumonia (PCP) is a potentially life-threatening but preventable infection that may occur after hematopoietic stem cell transplantation (HSCT). Intravenous pentamidine has been used in the prevention of PCP in the post-transplant period, although there are few trials published in the literature evaluating its safety and efficacy.

METHODS

We retrospectively reviewed the medical records of children who underwent HSCT from January 1, 2005, to October 1, 2011, who received intravenous pentamidine as first-line PCP prophylaxis initiated at admission. Demographic, clinical, microbiologic, management and outcome data were collected.

RESULTS

One hundred sixty-seven consecutive HSCTs in 137 pediatric patients were given intravenous pentamidine before myeloablation and then every 28 days until the subject was at least a minimum 30 days post-HSCT, had stable neutrophil engraftment (absolute neutrophil count >1000/mm for 3 days without growth factor support) and for allogeneic patients, no evidence of active graft versus host disease and weaning on their immunosuppressive therapy. No cases of PCP were seen in this cohort. Ten (7%) had a grade I side effect of nausea/vomiting requiring slower infusion time and 2 (2%) had a grade IV reaction with anaphylaxis (rash) and hypotension with 1 child requiring transfer to the intensive care unit.

CONCLUSIONS

Intravenous pentamidine was safe and effective for the prevention of PCP in pediatric HSCT patients. Given the potential neutropenic effects of trimethoprim-sulfamethoxazole, compliance with drug administration and inferior efficacy of other PCP prophylactic medications, intravenous pentamidine should be considered as first-line therapy for the prevention of PCP in children undergoing HSCT.

Effect of cimetidine on pentamidine induced hyperglycemia in rats

The antiprotozoal agent pentamidine, used for the treatment of Pneumocystis jirovecii pneumonia (PCP), is known to cause abnormalities in blood glucose homeostasis, such as hypoglycemia and hyperglycemia. Pentamidine has been reported to be a substrate of organic cation transporter 1 (OCT1). We investigated the combination effects of cimetidine, an OCT1 inhibitor, on the pharmacokinetics of pentamidine and on pentamidine-induced hyperglycemia. Pentamidine was infused intravenously to rats for 20 min at a dose of 7.5 or 15 mg/kg and serum samples were obtained periodically. The serum concentration of glucose did not change significantly after pentamidine infusion at 7.5mg/kg, while it increased with pentamidine at 15 mg/kg, and the maximal concentration of glucose was 167 ± 36 mg/dl, 30 min after the start of pentamidine infusion. Cimetidine (50mg/kg) enhanced the pentamidine-induced elevation of glucose concentration and the maximal concentration of glucose was 208 ± 33 mg/dl in the pentamidine 15 mg/kg treated group. Cimetidine combination significantly reduced total body clearance of pentamidine and increased pentamidine concentrations in the liver, kidneys, and lungs. A significant correlation was found between changes in serum glucose concentrations and serum concentrations of pentamidine 30 min after the start of pentamidine infusion. These results suggest that the hyperglycemic effect of pentamidine is dependent on the concentration of pentamidine and can be enhanced by cimetidine combination.

The efficacy of novel arylimidamides against Trypanosoma cruzi in vitro

The present study aimed to determine the in vitro biological efficacy and selectivity of 7 novel AIAs upon bloodstream trypomastigotes and intracellular amastigotes of Trypanosoma cruzi. The biological activity of these aromatic compounds was assayed for 48 and 24 h against intracellular parasites and bloodstream forms of T. cruzi (Y strain), respectively. Additional assays were also performed to determine their potential use in blood banks by treating the bloodstream parasites with the compounds diluted in mouse blood for 24 h at 4°C. Toxicity against mammalian cells was evaluated using primary cultures of cardiac cells incubated for 24 and 48 h with the AIAs and then cellular death rates were determined by MTT colorimetric assays. Our data demonstrated the outstanding trypanocidal effect of AIAs against T. cruzi, especially DB1853, DB1862, DB1867 and DB1868, giving IC50 values ranging between 16 and 70 nanomolar against both parasite forms. All AIAs presented superior efficacy to benznidazole and some, such as DB1868, also demonstrated promising activity as a candidate agent for blood prophylaxis. The excellent anti-trypanosomal efficacy of these novel AIAs against T. cruzi stimulates further in vivo studies and justifies the screening of new analogues with the goal of establishing a useful alternative therapy for Chagas disease.

Pneumocystis carinii Pneumonia Prophylaxis

Pneumocystis pneumonia (PCP) can be life threatening for children receiving chemotherapy and immunosuppressive medication, including high-dose steroids. Although there are no current guidelines for prophylaxis in pediatric oncology patients, ongoing studies are evaluating the efficacy, side effects, ease of administration, and compliance of drugs used for PCP prophylaxis. Drugs currently being prescribed in practice include Bactrim, pentamidine, dapsone, and atovaquone. Bactrim remains superior for preventing PCP, but alternatives are being analyzed and investigated for those unable to tolerate Bactrim because of drug allergy or side effects. Educating patients and families about the importance of PCP prophylaxis and compliance should be a priority for all health care providers caring for children receiving immunosuppressive medications, including chemotherapy.

Dapsone-induced methemoglobinemia: a dose-related occurrence?

BACKGROUND

Dapsone, used for Pneumocystis jiroveci (PCP) prophylaxis, is associated with increased risk of methemoglobinemia. Absence of cytochrome b5 reductase enzyme activity causes congenital methemoglobinemia, but its role in dapsone-associated methemoglobinemia is unknown. The authors sought to elucidate drug-related risk factors for dapsone-associated methemoglobinemia in pediatric oncology patients, including contribution of cytochrome b5 reductase enzyme activity.

METHODS

Among 167 pediatric patients treated for hematologic malignancies or aplastic anemia who received dapsone for PCP prophylaxis, demographic and dapsone treatment data were retrospectively collected. Drug-related risk factors were evaluated by Cox proportional hazards, and in a cross-sectional subgroup of 40 patients, cytochrome b5 reductase enzyme activity was assessed.

RESULTS

Methemoglobinemia (median methemoglobin level = 9.0% [3.5-22.4]) was documented in 32 (19.8%) patients. There was a 73% risk reduction in methemoglobinemia with dosing ≥20% below the target dose of 2 mg/kg/d (hazard ratio [HR], 0.27; 95% confidence interval [CI], 0.09-0.78; P = .016), whereas methemoglobinemia risk was increased with dosing ≥20% above the target dose (HR, 6.25; 95% CI, 2.45-15.93; P < .001). Sex, body mass index, and age were not associated with increased risk. Cytochrome b5 reductase enzyme activity did not differ by methemoglobinemia status (median 8.6 IU/g hemoglobin [Hb]; [5.5-12.1] vs 9.1 IU/g Hb; [6.7-12.7]). No patient developed PCP on dapsone.

CONCLUSIONS

Methemoglobinemia occurred in almost 20% of pediatric oncology patients receiving dapsone for PCP prophylaxis. Higher dapsone dosing is associated with increased risk. A cross-sectionally acquired cytochrome b5 reductase enzyme activity level was not associated with methemoglobinemia risk. Studies are needed to define biologic correlates of methemoglobinemia and evaluate lower dapsone doses for PCP prophylaxis.

Intermittent oral trimethoprim/sulfamethoxazole on two non-consecutive days per week is effective as Pneumocystis jiroveci pneumonia prophylaxis in pediatric patients receiving chemotherapy or hematopoietic stem cell transplantation

Pneumocystis jiroveci pneumonia (PCP) is a serious complication in patients receiving chemotherapy or hematopoietic stem cell transplantation. Current recommendations for trimethoprim-sulfamethoxazole (TMP-SMZ) dosing as PCP prophylaxis in immunocompromised patients are based on either daily dosing or dosing three consecutive days per week. We report our experience of prophylaxis with TMP-SMZ twice daily on two non-consecutive days per week in 145 immunocompromised children with hematologic disorders, cancer, or metabolic disorders following chemotherapy or hematopoietic stem cell transplantation. There were no breakthrough cases of PCP. We therefore conclude our prophylaxis regimen is effective against PCP in immunocompromised children.