Posaconazole vs. fluconazole or itraconazole prophylaxis in patients with neutropenia

A high-throughput LC-MS/MS method for the quantitation of posaconazole in human plasma: Implementing fused core silica liquid chromatography

A rapid and robust liquid chromatographic tandem mass spectrometric (LC-MS/MS) method for the determination of posaconazole concentrations in human plasma was validated. Posaconazole was extracted from human plasma using mixed-mode cation exchange solid phase extraction in a 96-well plate format followed by gradient separation on a fused-core Halo C18 column. The analyte and its corresponding internal standard were detected using a Sciex API 4000 triple quadrupole LC-MS/MS system equipped with a TurboIonSpray ionization source operated in the positive ion mode. The calibration range of the method was 5.00-5000ng/mL using a 50microL aliquot of plasma. The assay inter-run accuracy and precision were-4.6-2.8% and 2.3-8.7%, respectively (n=18). The results from method validation indicate the method to be sensitive, selective, accurate, and reproducible. The method was successfully applied to the routine analysis of clinical samples with the fused-core silica columns providing excellent reproducibility for greater than 1000 injections per column.

Posaconazole-increased vincristine neurotoxicity in a child: a case report

A 9-year-old girl was managed according to the COPRALL 04 protocol for treatment of a relapse of acute lymphoblastic leukemia. Owing to a previous case of disseminated fusariosis, posaconazole was started 5 days before initiation of chemotherapy. Six days after the last dose of vincristine, the child reported symptoms of severe peripheral neuropathy, abdominal cramps, and constipation. After this, she developed fluctuations in her level of consciousness and seizures. After cessation of therapy with posaconazole, a complete resolution of the above occurred within 7 days. This case illustrates the possibility of vincristine toxicity exacerbated by coadministration of posaconazole. As posaconazole is an inhibitor of the isoenzyme CYP3A4, interactions with drugs that are metabolized via this pathway, such as vincristine, can be anticipated. Another possibility is that, like itraconazole, posaconazole may also inhibit P-glycoprotein-mediated vincristine efflux. Although case reports of neurotoxicity owing to possible interaction between itraconazole and vincristine exist in the literature, only 1 case report relating to the possible interaction between posaconazole and vincristine exists. Clinicians should be made aware of this possible drug-drug interaction.

Invasive fungal infections in pediatric leukemia patients receiving fluconazole prophylaxis

BACKGROUND

Children with acute leukemia have increased risk for invasive fungal infections (IFI) but the role of long term antifungal prophylaxis (AFP) in morbidity and mortality of IFI is not well-known.

PROCEDURE

Medical records of 154 children with acute leukemia who received AFP with fluconazole during intensive chemotherapy were retrospectively reviewed to determine risk factors, clinical characteristics and outcome of IFI.

RESULTS

The overall incidence of IFI was 13.6%. Frequencies of proven, probable and possible infections were 7.2%, 2.6%, and 3.8%, respectively. The causative agent was Candida in 12 (57.2%) and Aspergillus in 9 (42.8%) children. There were 10 children with candidemia (47.6%), 7 with pulmonary aspergillosis (33.4%), 2 with hepatosplenic candidiasis (10.0%), one with sinopulmonary aspergillosis (4.5%) and one with sinus aspergillosis (4.5%). IFI was twice as common in acute myeloid leukemia (AML) (20.7%) than in acute lymphoblastic leukemia (ALL) (10.2%). Duration of profound neutropenia (P = 0.01) and steroid medications (P = 0.001) were significantly associated with IFI in univariate but not in multivariate analysis. Liposomal amphotericin B (L-AMB) was successful in 15 of 21 children as a single agent. Voriconazole produced complete response in four children with invasive aspergillosis and two with hepatosplenic candidiasis, who were unresponsive to L-AMB. The rate of IFI attributable death was 5%.

CONCLUSIONS

Our results indicate that AFP with fluconazole and early empirical antifungal therapy may be effective in reducing the incidence and mortality of IFI in children with acute leukemia.

Invasive aspergillosis: diagnosis, prophylaxis and treatment

PURPOSE OF REVIEW

Invasive aspergillosis is a common cause of morbidity and mortality in hematopoietic stem cells transplant recipients. Owing to its intrinsic high mortality rate, early diagnosis and treatment are critical. This review will therefore address the most important recent advances in diagnosing, preventing and treating invasive aspergillosis in hematopoietic stem cells transplant.

RECENT FINDINGS

The present review will focus on therapeutic and prophylactic aspects, with particular regard to clinical use of drugs other than voriconazole (which has a well known and consolidated role for first-line therapy), combination therapy and prophylactic regimens, particularly with posaconazole. This review will also briefly deal with the clinical role of diagnostic tests such as the detection of galactomannan in body fluids other than blood, beta-D-glucan in serum and fungal DNA by PCR in body fluids.

SUMMARY

Galactomannan antigen detection is a rather reliable diagnostic test for invasive aspergillosis, particularly when a lower threshold of sensitivity is used. PCR is still to be validated. Liposomal amphotericin B at 3 mg/kg per day showed a similar efficacy in invasive aspergillosis as reported for voriconazole. Therapeutic drug monitoring of Aspergillus-active azoles should be implemented whenever possible in order to maximize the antifungal effect and minimize toxicity. Posaconazole showed to be active in prophylaxis, though its effectiveness in the global patient population is still controversial.

Antifungal activities of natural and synthetic iron chelators alone and in combination with azole and polyene antibiotics against Aspergillus fumigatus

Antifungal effects of iron chelators (lactoferrin, deferoxamine, deferiprone, and ciclopirox) were tested alone and in combination with antifungal drugs against Aspergillus fumigatus B5233 conidia. Lactoferrin, ciclopirox, and deferiprone inhibited whereas deferoxamine enhanced fungal growth. Antifungal synergy against conidia was observed for combinations of ketoconazole with ciclopirox or deferiprone, lactoferrin with amphotericin B, and fluconazole with deferiprone. Iron chelation alone or combined with antifungal drugs may be useful for prevention and treatment of mycosis.

Modification of vincristine dosing during concomitant azole therapy in adult acute lymphoblastic leukemia patients

OBJECTIVE

Vincristine is an important component in the treatment of acute lymphoblastic leukemia (ALL) and is now the backbone of therapy in the induction and consolidation phases of this disease. Proper dosing of vincristine is required to maximize disease control while avoiding toxicity. The gastrointestinal toxicity of vincristine such as decreased peristalsis can potentially be increased if the CYP 3A4 enzyme is inhibited. This interaction may become more prevalent with increasing use of CYP 3A4 inhibitors such as the azole antifungals. Since azoles are increasingly being used for prophylaxis and treatment of fungal infections in this patient population, an assessment of vincristine dosing and toxicity is the first step to constructing guidelines for the coadministration of these agents.

METHODS

ALL patients !18 years of age receiving vincristine-based therapy from August 2003 through December 2007 with or without azole therapy were included. Data was collected using electronic patient medical records and the pharmacy system (RxTFC). Information was entered into a database for this retrospective study. Patients were separated into two arms; vincristine with azoles and vincristine only. Patient demographic information, chemotherapy regimen, vincristine-induced symptoms, and concurrent strong CYP 3A4 inhibitors and inducers were collected.

RESULTS

A total of 50 patients received vincristine of which 29 (58%) had concurrent azole therapy. No patients received concurrent major CYP 3A4 inhibitors and the baseline characteristics were similar between groups. Vincristine dosing modifications were more common in the azole group (58.6 vs. 23.8%; p = 0.02). The mean dose reduction of vincristine when combined with an azole was 46.5%. Symptoms of decreased peristalsis were more common in patients receiving azoles (65.5 vs. 28.6%; p = 0.019) and on average occurred after the second vincristine dose. Symptoms occurred in 50, 75, and 66.6% of patients receiving fluconazole, voriconazole, and posaconazole, respectively. Patients were more likely to have an incomplete course of vincristine when receiving azole therapy (48.3 vs. 9.5%; p = 0.004).

CONCLUSION

Caution should be used with the coadministration of vincristine and azoles. It is recommended that institutional guidelines be developed to standardize care for patients receiving vincristine with azole therapy. Potential measures to avoid this interaction include revisiting azole prophylaxis in this patient group and being judicious in azole selection.

Clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America

Guidelines for the management of patients with invasive candidiasis and mucosal candidiasis were prepared by an Expert Panel of the Infectious Diseases Society of America. These updated guidelines replace the previous guidelines published in the 15 January 2004 issue of Clinical Infectious Diseases and are intended for use by health care providers who care for patients who either have or are at risk of these infections. Since 2004, several new antifungal agents have become available, and several new studies have been published relating to the treatment of candidemia, other forms of invasive candidiasis, and mucosal disease, including oropharyngeal and esophageal candidiasis. There are also recent prospective data on the prevention of invasive candidiasis in high-risk neonates and adults and on the empiric treatment of suspected invasive candidiasis in adults. This new information is incorporated into this revised document.

Risk stratification for invasive aspergillosis: early assessment of host susceptibility

Outcomes of invasive aspergillosis are substantially improved with early initiation of therapy. Unfortunately, the diagnosis remains difficult to establish so that early suspicion of infection is imperative. Identification of high risk patients and use of non-culture-based diagnostics and radiographic studies can facilitate earlier recognition of infection. It is important to realize that the timing and spectrum of risk for invasive aspergillosis have expanded. While patients with hematological malignancies and hematopoietic stem cell transplants make up the highest risk groups, patients such as those receiving steroids and other immunosuppressive therapies are also at risk. Non-culture-based methods (including galactomannan, 1,3-beta-D-glucan, and PCR-based methods) are actively being pursued to improve early diagnosis. Thus, identifying patients at high risk for infection and utilizing non-culture-based methods and radiologic studies to assist in establishing a likely diagnosis of invasive aspergillosis will further enhance the role of new agents in the early, effective treatment and prophylaxis of invasive aspergillosis.

Isavuconazole: a new and promising antifungal triazole for the treatment of invasive fungal infections

Invasive fungal infections (IFIs) are an important cause of morbidity and mortality. Isavuconazole (BAL4815) is a promising novel broad-spectrum triazole in late-stage clinical development that has proven to be active in vitro against Aspergillus, Candida and Cryptococcus neoformans, the most common agents of IFIs. Furthermore, isavuconazole has a pharmacokinetic profile that allows oral and intravenous administration with no severe toxicity. In vivo data from animal models are also encouraging. However, very little information on clinical efficacy is available. Four clinical trials are currently in progress to demonstrate the safety and efficacy of isavuconazole for the treatment and prevention of IFIs. In the absence of clinical and cost data, the real possibilities of this agent as a competitor for the treatment and prevention of IFIs in the clinical setting are still unknown.

Therapeutic strategies for invasive fungal infections in neonatal and pediatric patients

Invasive Candida and Aspergillus infections are the most commonly encountered fungal infections. They appear to be life threatening in the setting of profound immunosuppression, whereas cases that are resistant to antifungal therapy are occasionally encountered. Novel antifungal triazole and echinocandin agents appear to exhibit good activity as first-line or salvage therapy, whereas the use of amphotericin B formulations is particularly valuable in neonates. Significant differences in toxicity have been demonstrated among various antifungal agents with in vitro activity from available comparative data on fungal infections in children: however, no clear difference in treatment efficacy has been demonstrated. However, very little data are available about neonates. Host factors and responsible fungal species most frequently guide the choice of therapy.

Comparative cost-effectiveness of posaconazole versus fluconazole or itraconazole prophylaxis in patients with prolonged neutropenia

PURPOSE

A cost-effectiveness analysis was performed to investigate the financial impact of using posaconazole versus fluconazole or itraconazole prophylaxis in patients with prolonged neutropenia.

METHODS

A decision-analytic model was developed from a hospital perspective based on the use of posaconazole versus fluconazole or itraconazole prophylaxis in patients with prolonged neutropenia (i.e., longer than 7-10 days). Data reported in a multicenter study, medication-cost information, and reports of costs to treat invasive fungal infections were used to accurately populate the model. Sensitivity analyses enhanced the robustness of the model through variation of all probabilities and costs.

RESULTS

In the base case, patients initiated on posaconazole displayed a 45% reduction in overall cost as compared with patients initiated on fluconazole or itraconazole ($3051 versus $5529, respectively). Sensitivity analyses determined that univariate changes in all model variables, including medication cost, duration of therapy, and cost of treating invasive fungal infections, did not impact overall results. A Monte Carlo simulation analysis found that use of posaconazole remains the best overall prophylactic strategy when taking into consideration the potential variance in all model assumptions. Posaconazole dominated the use of fluconazole or itraconazole because of previously demonstrated lower incidence of breakthrough fungal infections and lower overall treatment cost.

CONCLUSION

The decision model indicated that use of posaconazole as prophylaxis in patients with prolonged neutropenia should result in lower overall treatment costs relative to the cost of fluconazole or itraconazole.

Clinical indications for newer antifungal agents

Recent years have seen the release of multiple new systemic antifungal agents, significantly increasing options for the treatment of most serious fungal infections. Newly available drugs include those in the echinocandin class, including caspofungin, micafungin, and anidulafungin, as well as the newer generation triazoles, voriconazole and posaconazole. Ordering of these agents is variably restricted, depending on a given institution's policies, and all are costly. In this review we examine the available evidence and outline the role of newer antifungal medications in several common and/or important situations, including invasive and mucocutaneous Candida infection, febrile neutropenia, invasive aspergillosis, zygomycosis, and endemic mycoses.

Pharmacokinetics of oral posaconazole in neutropenic patients receiving chemotherapy for acute myelogenous leukemia or myelodysplastic syndrome

STUDY OBJECTIVE

To analyze the pharmacokinetics of posaconazole administered as prophylaxis for invasive fungal infection (IFI) in neutropenic patients receiving chemotherapy for acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS).

DESIGN

Pharmacokinetic subanalysis of a phase III, prospective, randomized, multicenter, evaluator-blinded trial comparing posaconazole with standard azoles (fluconazole and itraconazole).

PATIENTS

One hundred ninety-four patients with AML or MDS who received posaconazole oral suspension 200 mg 3 times/day with meals or a nutritional supplement for a minimum of 7 days to achieve steady state and for a maximum of 12 weeks.

INTERVENTION

For the first 20 patients, blood samples were collected before the first dose on day 8 and at 2, 4, 6, and 24 hours after that first dose; for all other patients, blood samples were collected at 1 and 3 hours after the first dose on day 8 and during the first episode of evaluation for a possible IFI.

MEASUREMENTS AND MAIN RESULTS

The effects of the following covariates on average (Cav) and maximum (Cmax) posaconazole plasma concentrations at steady state were explored: age, sex, and race-ethnicity; proven or probable IFI; baseline body weight and body surface area; and baseline (on or before day 7) increases in liver enzyme levels, mucositis, neutropenia, diarrhea, vomiting, or use of an H2-receptor antagonist or proton pump inhibitor. Diarrhea, proton pump inhibitor use, gamma-glutamyl transferase level of 2 or more times the upper limit of normal, and race-ethnicity reduced Cav. Although statistically significant, these results were not considered clinically significant and did not necessitate posaconazole dosage adjustments. Mean Cav and Cmax values did not appear different in the six patients with IFIs (three with proven IFIs, three with probable IFIs) compared with the entire sample of 194 patients; however, a definitive conclusion cannot be made due to the small sample size of patients with IFI. No factor found to affect posaconazole concentrations predominated in patients with IFIs.

CONCLUSION

Oral posaconazole 200 mg 3 times/day provided plasma concentrations adequate for preventing IFIs. No dosage adjustments are recommended based on any covariate tested.

Stem Cell Transplantation

Hematopoietic cell transplantation (HCT) is associated with profound compromises in host defenses. The patterns of immune compromise change over time. Infections are an important cause of serious morbidity and pose substantial threats to life. Thus, the challenges of infection facing the transplant clinician are both myriad and dynamic. Early after transplant, neutropenic infections are most important. Later herpesvirus and invasive fungal infections predominate. Even late after transplant, patients with chronic graft versus host disease remain susceptible to encapsulated bacterial, varicella zoster virus, and invasive fungal infections. Over time, with robust engraftment and control of GVHD, the risk of serious infections recedes with immune reconstitution.

Acute Myelogenous Leukemia and Febrile Neutropenia

Aggressive chemotherapy has a deleterious effect on all components of the defense system of the human body. The resulting neutropenia as well as injury to the pulmonary and gastrointestinal mucosa allow pathogenic micro-organisms easy access to the body. The symptoms of an incipient infection are usually subtle and limited to unexplained fever due to the absence of granulocytes. This is the reason why prompt administration of antimicrobial agents while waiting for the results of the blood cultures, the so-called empirical approach, became an undisputed standard of care. Gram-negative pathogens remain the principal concern because their virulence accounts for serious morbidity and a high early mortality rate. Three basic intravenous antibiotic regimens have evolved: initial therapy with a single antipseudomonal β-lactam, the so-called monotherapy; a combination of two drugs: a β-lactam with an aminoglycoside, a second β-lactam or a quinolone; and, thirdly, a glycopeptide in addition to β-lactam monotherapy or combination. As there is no single consistently superior empirical regimen, one should consider the local antibiotic susceptibility of bacterial isolates in the selection of the initial antibiotic regimen. Not all febrile neutropenic patients carry the same risk as those with fever only generally respond rapidly, whereas those with a clinically or microbiologically documented infection show a much slower reaction and less favorable response rate.

Once an empirical antibiotic therapy has been started, the patient must be monitored continuously for nonresponse, emergence of secondary infections, adverse effects, and the development of drug-resistant organisms. The averageduration of fever in serious infections in eventually successfully treated neutropenic patients is 4–5 days. Adaptations of an antibiotic regimen in a patient who is clearly not responding is relatively straightforward when a micro-organism has been isolated; the results of the cultures, supplemented by susceptibility testing, will assist in selecting the proper antibiotics. The management of febrile patients with pulmonary infiltrates is complex. Bronchoscopy and a high resolution computer-assisted tomographic scan represent the cornerstones of all diagnostic procedures, supplemented by serological tests for relevant viral pathogens and for aspergillosis. Fungi have been found to be responsible for two thirds of all superinfections that may surface during broad-spectrum antibiotic treatment of neutropenic patients. Antibiotic treatment is usually continued for a minimum of 7 days or until culture results indicate that the causative organism has been eradicated and the patient is free of major signs and symptoms. If a persistently neutropenic patient has no complaints and displays no evidence of infection, early watchful cessation of antibiotic therapy or a change to the oral regimen should be considered.

Primary prophylaxis of invasive fungal infections in patients with hematologic malignancies. Recommendations of the Infectious Diseases Working Party of the German Society for Haematology and Oncology

There is no widely accepted standard for antifungal prophylaxis in patients with hematologic malignancies. The Infectious Diseases Working Party of the German Society for Haematology and Oncology assigned a committee of hematologists and infectious disease specialists to develop recommendations. Literature data bases were systematically searched for clinical trials on antifungal prophylaxis. The studies identified were shared within the committee. Data were extracted by two of the authors (OAC and MSi). The consensus process was conducted by email communication. Finally, a review committee discussed the proposed recommendations. After consensus was established the recommendations were finalized. A total of 86 trials were identified including 16,922 patients. Only a few trials yielded significant differences in efficacy. Fluconazole 400 mg/d improved the incidence rates of invasive fungal infections and attributable mortality in allogeneic stem cell recipients. Posaconazole 600 mg/d reduced the incidence of IFI and attributable mortality in allogeneic stem cell recipients with severe graft versus host disease, and in patients with acute myelogenous leukemia or myelodysplastic syndrome additionally reduced overall mortality. Aerosolized liposomal amphotericin B reduced the incidence rate of invasive pulmonary aspergillosis. Posaconazole 600 mg/d is recommended in patients with acute myelogenous leukemia/myelodysplastic syndrome or undergoing allogeneic stem cell recipients with graft versus host disease for the prevention of invasive fungal infections and attributable mortality (Level A I). Fluconazole 400 mg/d is recommended in allogeneic stem cell recipients until development of graft versus host disease only (Level A I). Aerosolized liposomal amphotericin B is recommended during prolonged neutropenia (Level B II).

Outcome and medical costs of patients with invasive aspergillosis and acute myelogenous leukemia-myelodysplastic syndrome treated with intensive chemotherapy: an observational study

BACKGROUND

Invasive aspergillosis (IA) is a leading cause of mortality in patients with acute leukemia. Management of IA is expensive, which makes prevention desirable. Because hospital resources are limited, prevention costs have to be compared with treatment costs and outcome.

METHODS

In 269 patients treated for acute myelogenous leukemia-myelodysplastic syndrome (AML-MDS) during 2002-2007, evidence of IA was collected using high-resolution computed tomography and galactomannan measurement in bronchoalveolar lavage fluid specimens. IA was classified on the basis of updated European Organization for Research and Treatment of Cancer/Mycoses Study Group definitions. Outcome of infection was registered. Diagnostic and therapeutic IA-related costs, corrected for neutropenia duration, were comprehensively analyzed from a hospital perspective. Voriconazole treatment was given orally from day 1 if possible.

RESULTS

A total of 80 patients developed IA; 48 (18%) had probable or proven infection, and 32 (12%) had possible IA. Seventy-three patients were treated with voriconazole; 55 (75%) took oral voriconazole from day 1. In patients with IA, the mortality rate 12 weeks after starting antifungal therapy was 22% (16 of 73 patients). The overall mortality rate, registered 12 weeks after neutrophil recovery from the last dose of antileukemic treatment, was 26% in patients with IA versus 16% in patients without IA (P = .08), reflecting an IA-attributable mortality rate of 10%. In a Cox regression analysis, IA was associated with an increased mortality risk (hazard ratio, 2.4; 95% confidence interval, 1.3-4.4). Total IA-related costs increased to euro 8360 and euro 15,280 for patients with possible and probable or proven IA, respectively, compared with patients without IA (P<.001).

CONCLUSIONS

Early diagnosis and treatment of IA with oral voriconazole result in acceptable mortality rates. Nevertheless, IA continues to have substantial attributable mortality combined with a major impact on hospital resource use, so effective prevention in high-incidence populations has the potential to save lives and costs.

Pharmacokinetics and absorption of posaconazole oral suspension under various gastric conditions in healthy volunteers

A four-part, randomized, crossover study with healthy subjects evaluated the effects of gastric pH, the dosing frequency and prandial state, food consumption timing, and gastric motility on the absorption of posaconazole. In part 1, a single dose (SD) of posaconazole (400 mg) was administered alone or with an acidic beverage or a proton pump inhibitor (PPI), or both. In part 2, posaconazole (400 mg twice daily and 200 mg four times daily) was administered for 7 days with and without a nutritional supplement (Boost). In part 3, an SD of posaconazole (400 mg) was administered while the subjects were fasting and before, during, and after a high-fat meal. In part 4, an SD of posaconazole (400 mg) and the nutritional supplement were administered alone, with metoclopramide, and with loperamide. Compared to the results obtained with posaconazole alone, administration with an acidic beverage increased the posaconazole maximum concentration in plasma (C(max)) and the area under the concentration-time curve (AUC) by 92% and 70%, respectively, whereas a higher gastric pH decreased the posaconazole C(max) and AUC by 46% and 32%, respectively. Compared to the results obtained with posaconazole alone, posaconazole at 400 mg or at 200 mg plus the nutritional supplement increased the posaconazole C(max) and AUC by 65% and 66%, respectively, and by up to 137% and 161%, respectively. Administration before a high-fat meal increased the C(max) and the AUC by 96% and 111%, respectively, while administration during and after the meal increased the C(max) and the AUC by up to 339% and 387%, respectively. Increased gastric motility decreased the C(max) and the AUC by 21% and 19%, respectively. Strategies to maximize posaconazole exposure in patients with absorption difficulties include administration with or after a high-fat meal, with any meal or nutritional supplement, with an acidic beverage, or in divided doses and the avoidance of proton pump inhibitors.

Newer antifungal agents for invasive fungal infections in patients with haematological malignancy

Since 2001 five new systemically administered antifungal agents have been approved for clinical use. This represents a major advance for antifungal therapy in haematological malignancy patients undergoing chemotherapy or haematopoietic stem cell transplant (HSCT). The echinocandins are a new class of antifungals with a novel mode of action. Capsofungin has already established itself as a valuable therapy for candidaemia and salvage therapy of invasive aspergillosis. Although both anidulafungin and micafungin are approved for treatment of candidiasis, their role in invasive aspergillosis requires more clinical trial evaluation. Of the two newer triazoles, voriconazole has been recommended in international guidelines as primary therapy for acute invasive aspergillosis. Posaconazole has a broad spectrum of activity in vitro and a potentially key role in antifungal prophylaxis in high-risk HSCT recipients and during prolonged neutropenia. Although some of these drugs have important interactions with other medications, and potential toxicities, they are safer to use and more efficacious than amphotericin B deoxycholate. Their arrival gives more choices to treat rarer mycoses and will facilitate clinical trial assessment of combination therapy of aspergillosis where single agent therapy gives less than 50% success rates.

Therapeutic drug monitoring for triazoles

PURPOSE OF REVIEW

Invasive fungal infections are a leading cause of morbidity and mortality in immunocompromised patients, and mechanisms to optimize therapeutic outcomes are urgently required. Therapeutic drug monitoring represents an important component for the routine use of the triazoles.

RECENT FINDINGS

Triazoles have revolutionized the prevention and treatment of invasive fungal infections. Increasing data suggest that this class displays important concentration-effect and concentration-toxicity relationships. There has been an increased understanding of the pharmacokinetics and pharmacodynamics of triazoles, and this has facilitated the identification of concentrations (or drug exposures) that are both effective and nontoxic. This review discusses the application of therapeutic drug monitoring to fluconazole, itraconazole, voriconazole and posaconazole.

SUMMARY

Therapeutic drug monitoring represents an important mechanism to optimize the outcome of immunocompromised patients receiving triazoles.

Breakthrough invasive fungal infection in an immunocompromised host while on posaconazole prophylaxis: an omission in patient counseling and follow-up

Posaconazole (Noxafil ® Schering-Plough Corporation) is a triazole antifungal approved in the United States for the treatment of oropharyngeal candidiasis and for the prophylaxis of Candida and Aspergillus infections in the immunocompromised host. Posaconazole is available only as an oral suspension. When used for the prevention of Candida and Aspergillus infections, posaconazole should be taken three times daily with a high fat meal to maximize oral absorption. Failure to take posaconazole with food will lead to subtherapeutic serum levels and decreased clinical effectiveness of the drug.

We report the case of a 49-year-old woman with acute myeloid leukemia who received 4 months of posaconazole as an outpatient for the labeled indication of prophylaxis of Candida and Aspergillus infections. During her last admission, the patient presented with an invasive sinus infection diagnosed as a mixed Aspergillus and Mucor etiology. The patient succumbed to this infection five weeks after presentation. Upon investigation it was found that the patient did not self-administer posaconazole as required in the product labeling, which may have led to drug failure in this patient. We submit this case to illustrate the importance of patient education regarding proper administration of posaconazole. The important role of the outpatient physician, nurse, and pharmacist in this setting is underscored. J Oncol Pharm Practice (2008) 14: 189—193.

Intrapulmonary pharmacokinetics and pharmacodynamics of posaconazole at steady state in healthy subjects

We evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of posaconazole (POS) in a prospective, open-label study. Twenty-five healthy adults received 14 doses of POS oral suspension (400 mg twice daily) with a high-fat meal over 8 days. Pulmonary epithelial lining fluid (ELF) and alveolar cell (AC) samples were obtained via bronchoalveolar lavage, and blood samples were collected during the 24 h after the last dose. POS concentrations were determined using liquid chromatography with tandem mass spectrometry parameters. The maximum concentrations (C(max)) (mean +/- standard deviation) in plasma, ELF, and ACs were 2.08 +/- 0.93, 1.86 +/- 1.30, and 87.7 +/- 65.0 microg/ml. The POS concentrations in plasma, ELF, and ACs did not decrease significantly, indicating slow elimination after multiple dosing. The mean concentrations of POS in plasma, ELF, and ACs were above the MIC(90) (0.5 microg/ml) for Aspergillus spp. over the 12-h dosing interval and for 24 h following the last dose. Area under the curve from 0 to 12 h (AUC(0-12)) ratios for ELF/plasma and AC/plasma were 0.84 and 33. AUC(0-24)/MIC(90) ratios in plasma, ELF, and AC were 87.6, 73.2, and 2,860. Nine (36%) of 25 subjects had treatment-related adverse events during the course of the study, which were all mild or moderate. We conclude that a dose of 400 mg twice daily resulted in sustained plasma, ELF, and AC concentrations above the MIC(90) for Aspergillus spp. during the dosing interval. The intrapulmonary PK/PD of POS are favorable for treatment or prevention of aspergillosis, and oral POS was well tolerated in healthy adults.

Postoperative infectious complications of abdominal solid organ transplantation

There is a rapidly growing population of immunocompromised organ transplant recipients. These patients are at risk of a large variety of infections that have significant consequences on mortality, graft dysfunction, and graft loss. The diagnosis and treatment of these infections are facilitated by an understanding of the preoperative, perioperative, and postoperative risk factors; the typical pathogens; and their characteristic time of presentation. On the basis of these factors, we put forth an algorithm for diagnosing and treating suspected infections in solid organ transplant recipients.

Results of a local antibiotic management program on antibiotic use in a tertiary intensive care unit in Hungary

BACKGROUND

Massive antibiotic use in intensive care units (ICU) is associated with increased microbial resistance. Therefore avoiding unneccesary antibiotic usage is essential. To achieve a more considered antibiotic prescribing practice, a new antibiotic policy was implemented at our ICU. In this paper, we evaluated the impact of this intervention, and described the aetiology and incidence of blood stream infections and selected antibiotic-resistant pathogens.

MATERIALS AND METHODS

In November 2002, a local antibiotic management program (LAMP) was implemented. This included a new infectious diseases specialist consultation service and restricted authorisation to prescribe antibiotics. The effect on ward-level antibiotic use was examined by segmented regression analysis. Patient, ICU and microbiology data were also recorded and compared before and after policy implementation.

RESULTS

The patient populations and the subsequent mortality rate were comparable before and after the implementation of the policy. Total antibiotic consumption was markedly reduced from 162.9 to 101.3 defined daily dose (DDD) per 100 patients, and per day (DDD per 100 patient-days). This was mainly accounted for a reduction in the use of quinolones, aminoglycosides, glycopeptides, metronidazol, carbepenems and third generation cephalosporins.

CONCLUSION

This study has confirmed that establishing a targeted LAMP, based on close co-operation between intensive care physicians and infectious disease specialists together with a restricted prescribing authority, can reduce the use of antibiotics.

Emergence of azole resistance in Aspergillus fumigatus and spread of a single resistance mechanism

BACKGROUND

Resistance to triazoles was recently reported in Aspergillus fumigatus isolates cultured from patients with invasive aspergillosis. The prevalence of azole resistance in A. fumigatus is unknown. We investigated the prevalence and spread of azole resistance using our culture collection that contained A. fumigatus isolates collected between 1994 and 2007.

METHODS AND FINDINGS

We investigated the prevalence of itraconazole (ITZ) resistance in 1,912 clinical A. fumigatus isolates collected from 1,219 patients in our University Medical Centre over a 14-y period. The spread of resistance was investigated by analyzing 147 A. fumigatus isolates from 101 patients, from 28 other medical centres in The Netherlands and 317 isolates from six other countries. The isolates were characterized using phenotypic and molecular methods. The electronic patient files were used to determine the underlying conditions of the patients and the presence of invasive aspergillosis. ITZ-resistant isolates were found in 32 of 1,219 patients. All cases were observed after 1999 with an annual prevalence of 1.7% to 6%. The ITZ-resistant isolates also showed elevated minimum inhibitory concentrations of voriconazole, ravuconazole, and posaconazole. A substitution of leucine 98 for histidine in the cyp51A gene, together with two copies of a 34-bp sequence in tandem in the gene promoter (TR/L98H), was found to be the dominant resistance mechanism. Microsatellite analysis indicated that the ITZ-resistant isolates were genetically distinct but clustered. The ITZ-sensitive isolates were not more likely to be responsible for invasive aspergillosis than the ITZ-resistant isolates. ITZ resistance was found in isolates from 13 patients (12.8%) from nine other medical centres in The Netherlands, of which 69% harboured the TR/L98H substitution, and in six isolates originating from four other countries.

CONCLUSIONS

Azole resistance has emerged in A. fumigatus and might be more prevalent than currently acknowledged. The presence of a dominant resistance mechanism in clinical isolates suggests that isolates with this mechanism are spreading in our environment.

Invasive opportunistic mycoses: clinical trials review, 2007-2008

Invasive fungal infections are important causes of morbidity and mortality in severely ill patients. The past decade has seen considerable expansion in the development of new antifungal compounds, and clinical trials continue to define their role in our antifungal armamentarium. This brief article summarizes the most pivotal clinical trials in the settings of treatment and prophylaxis of invasive opportunistic mycoses published between 2007 and 2008.