Posaconazole Therapeutic Drug Monitoring in the Real-life Setting: A Single-Center Experience and Review of the Literature

Model-informed precision dosing: State of the art and future perspectives

Model-informed precision dosing (MIPD) stands as a significant development in personalized medicine to tailor drug dosing to individual patient characteristics. MIPD moves beyond traditional therapeutic drug monitoring (TDM) by integrating mathematical predictions of dosing, and considering patient-specific factors (patient characteristics, drug measurements) as well as different sources of variability. For this purpose, rigorous model qualification is required for the application of MIPD in patients. This review delves into new methods in model selection and validation, also highlighting the role of machine learning in improving MIPD, the utilization of biosensors for real-time monitoring, as well as the potential of models integrating biomarkers for efficacy or toxicity for precision dosing. The clinical evidence of TDM and MIPD is discussed for various medical fields including infection medicine, oncology, transplant medicine, and inflammatory bowel diseases, thereby underscoring the role of pharmacokinetics/pharmacodynamics and specific biomarkers. Further research, particularly randomized clinical trials, is warranted to corroborate the value of MIPD in enhancing patient outcomes and advancing personalized medicine.

Updated antimicrobial dosing recommendations for obese patients

The prevalence of obesity has increased considerably in the last few decades. Pathophysiological changes in obese patients lead to pharmacokinetic (PK) and pharmacodynamic (PD) alterations that can condition the correct exposure to antimicrobials if standard dosages are used. Inadequate dosing in obese patients can lead to toxicity or therapeutic failure. In recent years, additional antimicrobial PK/PD data, extended infusion strategies, and studies in critically ill patients have made it possible to obtain data to provide a better dosage in obese patients. Despite this, it is usually difficult to find information on drug dosing in this population, which is sometimes contradictory. This is a comprehensive review of the dosing of different types of antimicrobials (antibiotics, antifungals, antivirals, and antituberculosis drugs) in obese patients, where the literature on PK and possible dosing strategies in obese adults was critically assessed.

A Prospective Study to Evaluate the Effect of Therapeutic Drug Monitoring-Based Posaconazole Prophylaxis on Invasive Fungal Infection Rate During Acute Myeloid Leukemia Induction Therapy

Invasive fungal infections (IFIs) are a significant cause of morbidity and mortality in de-novo acute myeloid leukemia patients receiving induction chemotherapy. Despite using posaconazole, a broad-spectrum antifungal, for IFI prophylaxis, the breakthrough IFI rate is high in the real-world setting. One of the reasons could be frequent suboptimal plasma posaconazole levels. In the present study, we evaluated if therapeutic drug monitoring (TDM) guided posaconazole prophylaxis can reduce the IFI rates in comparison to a historical cohort. We enrolled 90 patients, > / = 16 years of age, without baseline IFIs, planned for remission induction therapy. All patients were started on posaconazole suspension 200 mg TDS and the dose was increased in a stepwise manner if trough levels were found to be suboptimal (< 350 ng/ml for day 2 or < 700 ng/ml subsequently). The TDM based approach resulted in a significant decline in breakthrough IFI rates (18% versus 52%, P < 0.0001) A total of 69 patients (78%) required dose escalation. Thirty-one patients required change in antifungals due to either suboptimal levels, persistent fever, diarrhoea or vomiting. We could not demonstrate an exposure-response relationship but the difference in IFI rates in patients with a median posaconazole level > / = 700 ng/ml (0%) and < 700 ng/ml (21.6%) was clinically meaningful. Posaconazole levels were found to be significantly lower in patients on antacids and prokinetics. The incidence of posaconazole-related grade 3 toxicity was low (2.3%). Thus TDM-based dosing of posaconazole helps reduce breakthrough IFI rate and should be a part of posaconazole prophylaxis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-023-01709-3.

Exposure-Response Relationship of Posaconazole Suspension in Theprophylaxis of Invasive Fungal Infections in Patients with Acute Myeloid Leukemia

Purpose

Antifungal prophylaxis with posaconazole has demonstrated a reduction in the risk of death due to Invasive fungal infections (IFI)in patients with acute myeloid leukemia (AML) during induction therapy. However, various factors affect the plasma levels of posaconazole and can potentially limit its efficacy. Therapeutic drug monitoring (TDM) can help optimize the dose, but literature is scant from centers with a high IFI burden. This study aimed to evaluate the proportion of de-novo AML patients on induction who could achieve the target level of 700ng/mL with posaconazole prophylaxis,factors that can influence the plasma levels, and the impact of plasma posaconazole levels on incidence of IFI.

Methods

Patients with AML on induction therapy with no baseline IFI were enrolled at our tertiary cancer center which has high prevalence of IFI. These patients received posaconazole suspension as prophylaxis. Daily plasma levels were measured from Day 4 till Day 12 of posaconazole prophylaxis. All patients were monitored for the development of IFI. The data on adverse events, concomitant drugs, mucositis, vomiting, and diarrhea were recorded.

Results

A total of 411 samples from fifty patients were collected. Only 177 out of 411 samples had levels > 700 ng/mL. The median trough level was 610 ng/mL (range30-3000 ng/mL). The median time to achieve target trough concentration was four days (range 4-12 days) from the start of induction.Thirty-eight (76%) patients achieved target plasma levels by day 12 of induction.The median plasma level on day 12 was 690 ng/mL (range,30-1270) in patients who achieved target levels as compared to 340 (50-560) ng/mL in those who did not. Twenty-six (52%) patients had IFI in our study, and the median time to develop breakthrough IFI was 14 days (range 4-24 days). Median and range of plasma levels were 690 ng/ml (30-2410; n = 22) in those who developed IFI, while 590 ng/mL (50-2300 n = 24) in those who did not. The odds of developing IFI in patients who did not achieve the threshold trough concentration of 700 ng/mL was 7.14 (95% CI; 1.35-37.75, p = 0.0206). Occurrence of vomiting (p = 0.02), diarrhea (p = 0.0008), mucositis (p = 0.003) had adverse impact on achievement of target plasma posaconazole levels.

Conclusion

A significant proportion of patients receiving posaconazole prophylaxis fail to achieve target plasma levels which can result in high risk of development of IFI. Occurrence of diarrhea, vomiting and mucositis can adversely affect the achievement target plasma levels.

Blastomycosis: A Review of Mycological and Clinical Aspects

Blastomycosis is caused by a thermally dimorphic fungus that thrives in moist acidic soil. Blastomyces dermatitidis is the species responsible for most infections in North America and is especially common in areas around the Great Lakes, the St. Lawrence Seaway, and in several south-central and southeastern United States. Other Blastomyces species have more recently been discovered to cause disease in distinct geographic regions around the world. Infection almost always occurs following inhalation of conidia produced in the mold phase. Acute pulmonary infection ranges from asymptomatic to typical community-acquired pneumonia; more chronic forms of pulmonary infection can present as mass-like lesions or cavitary pneumonia. Infrequently, pulmonary infection can progress to acute respiratory distress syndrome that is associated with a high mortality rate. After initial pulmonary infection, hematogenous dissemination of the yeast form of Blastomyces is common. Most often this is manifested by cutaneous lesions, but osteoarticular, genitourinary, and central nervous system (CNS) involvement also occurs. The diagnosis of blastomycosis can be made by growth of the mold phase of Blastomyces spp. in culture or by histopathological identification of the distinctive features of the yeast form in tissues. Detection of cell wall antigens of Blastomyces in urine or serum provides a rapid method for a probable diagnosis of blastomycosis, but cross-reactivity with other endemic mycoses commonly occurs. Treatment of severe pulmonary or disseminated blastomycosis and CNS blastomycosis initially is with a lipid formulation of amphotericin B. After improvement, therapy can be changed to an oral azole, almost always itraconazole. With mild to moderate pulmonary or disseminated blastomycosis, oral itraconazole treatment is recommended.

Real-world assessment of the effectiveness of posaconazole for the prophylaxis and treatment of invasive fungal infections in hematological patients: A retrospective observational study

The aim of the study was to analyze the efficacy of posaconazole for the prophylaxis and treatment of invasive fungal diseases (IFDs) in patients with hematological malignancies.In this retrospective observational multi-center study, 762 patients from 25 Chinese hematological centers were enrolled. Inclusion criteria were patients with hematological malignancy or they had undergone hematopoietic stem cell transplantation and received at least 1 dose of posaconazole. The primary endpoints were the observation of breakthrough rates and the clinical efficacy of posaconazole prophylaxis. The secondary endpoint was the efficacy of posaconazole for the treatment of IFDs.Of the 762 enrolled patients, 456 (59.8%) were prescribed posaconazole prophylactically while 243 (31.9%) received posaconazole as an IFD treatment (12 proven, 61 probable, 109 possible, and 61 unclassified IFD cases) for ≥7 days. The overall IFD breakthrough rate (probable cases) for the ≥4 days prophylactic treatment (n = 445) group was 1.6% (95% Cl: 0.6%-3.2%), with breakthrough rates of 2.6% for acute myeloid leukemia/myelodysplastic syndrome patients undergoing chemotherapy and 2.2% for hematopoietic stem cell transplantation patients. For primary antifungal prophylaxis, the breakthrough rate was 1.9% and for secondary antifungal prophylaxis 0%. The overall effective IFD remission rate of patients treated for ≥7 days with posaconazole was 56.0% and the effective remission rate of proven/probable/possible IFD cases was 59.3%. The effective remission rate of posaconazole as salvage therapy was 50% (95% CI: 32.4%-67.6%) including 75% (CI: 19.4%-99.4%) for Aspergillus infections.The present retrospective study confirmed posaconazole as IFD prophylaxis and medication for hematological malignancy patients undergoing various treatments in China.

Optimal oral cyclosporin dosing with concomitant posaconazole post allogeneic stem cell transplantation

Cyclosporin is an immunosuppressive agent in allogeneic hematopoietic stem cell transplantation and its metabolism is strongly affected by concomitant drugs, including posaconazole which is now extensively used as anti-fungal prophylaxis post-allograft. We undertook a retrospective audit of 29 patients undergoing their first allograft who were receiving posaconazole at the time of transition from intravenous to oral cyclosporin. This group had a median initial oral cyclosporin dose of 2.58 mg/kg bd (range 1.75-3.95) and high incidence of cyclosporin-related toxicity was noted, requiring significant dose reductions such that by day 60 the media dose was 1.60 mg/kg bd (range 0.86-3.33). We subsequently amended our dosing protocol and analyzed a further 20 patients specifying an initial oral cyclosporin dose of 2.25 mg/kg bd and found this had little impact on toxicity or requirement for dose reductions. Starting doses of no greater than 2 mg/kg bd appear optimal to prevent toxicity in allograft recipients receiving concomitant posaconazole.

Impact of patient education on plasma concentrations and effectiveness of posaconazole oral suspension under clinical conditions

Posaconazole prophylaxis is recommended for patients with acute myeloid leukaemia during induction chemotherapy. Although a tablet formulation with better oral bioavailability is available, some patients have to rely on the oral suspension in clinical routine. Therefore, effectiveness of posaconazole oral suspension under real-life clinical conditions and impact of patient education about the correct intake on its plasma concentrations were assessed in this study. Altogether 96 patients receiving 160 cycles of induction chemotherapy were retrospectively (40 patients) and prospectively (56 patients) analysed. Patients were assigned into two groups for each chemotherapy cycle according to the application of antifungal prophylaxis (A: posaconazole oral suspension, 200 mg three times a day ≥7 days; B: intake <7 days, fluconazole or no prophylaxis). Antifungal prophylaxis and therapy were analysed for each cycle. Additionally, plasma concentrations were determined from prospectively included subjects of group A who were intensively educated to perform a correct drug intake. Systemic antifungal therapy was statistically started less often in group A (26% vs 53%; P = 0.002). Posaconazole prophylaxis was associated with a lower risk of proven invasive fungal infection (P = 0.003). Median plasma concentration apparently increased between the first and second time of determination effected by an initial intensive on-site patient education. The clinical effectiveness of posaconazole oral suspension was confirmed. A detailed patient education at the beginning of the treatment with posaconazole oral suspensions seems to be of primary importance for efficient plasma concentrations.

Risk factors for subtherapeutic levels of posaconazole tablet

Background

Posaconazole is the prophylactic antifungal of choice for patients with haematological malignancies at high risk of invasive fungal infections (IFIs). Studies have demonstrated that subtherapeutic concentrations of posaconazole are associated with breakthrough fungal infections and specific risk factors for subtherapeutic troughs associated with the suspension formulation have been identified. However, these risk factors have not been evaluated in a large patient population with the recently approved tablet formulation.

Objectives

To determine the risk factors for subtherapeutic posaconazole troughs associated with the tablet formulation in patients receiving posaconazole as IFI prophylaxis.

Patients and methods

From 1 February 2013 to 31 March 2015 all posaconazole serum trough concentrations were evaluated. A total of 157 patients receiving posaconazole tablet for prophylaxis during induction therapy for haematological malignancies and allogeneic stem cell transplant recipients with graft-versus-host disease were included for analysis.

Results

Overall, 28 patients (18%) had subtherapeutic troughs (<700 ng/mL). Patients were more likely to have subtherapeutic troughs if they had diarrhoea (n = 24; 83%) (P < 0.001), were receiving a proton pump inhibitor (n = 27; 93%) (P = 0.016) and weighed >90 kg (n = 14; 48%) (P = 0.047).

Conclusions

While the posaconazole tablet has provided more consistent therapeutic concentrations when compared with the suspension there may still be a role for therapeutic drug monitoring (TDM). These results may guide us to a specific population in which TDM is necessary to identify subtherapeutic troughs.

Utility of posaconazole therapeutic drug monitoring and assessment of plasma concentration threshold for effective prophylaxis of invasive fungal infections: a meta-analysis with trial sequential analysis

Background

Posaconazole therapeutic drug monitoring (TDM) is increasingly used in clinical practice. However, the utility of posaconazole TDM and the target of posaconazole plasma concentration for clinical successful prophylaxis remain uncertain and controversial. The aim of this study was to evaluate posaconazole exposure-response relationship and determine an optimum posaconazole concentration for prophylaxis against invasive fungal infections (IFIs).

Methods

Bibliographic databases were searched (from inception to September 2017) to select studies including the clinical outcomes below and above concentration cut-off value of 0.5 mg/L and 0.7 mg/L. The reliability of the results were evaluated with trial sequential analysis (TSA).

Results

Twenty-eight studies with 1930 patients included were analyzed. The results of our pooled analysis demonstrated that patients with posaconazole plasma concentrations over 0.5 mg/L were twice more likely to achieve successful responses compared with those with lower concentrations (odds ratio, OR = 1.98, 95% confidence interval, CI 1.09–3.58, P = 0.02) while the threshold, 0.7 mg/L showed no significant difference (OR = 1.84, 95% CI 0.94–3.63, P = 0.08). The TSA results showed that there was sufficient information to support these findings.

Conclusions

An optimal posaconazole concentration target of 0.5 mg/L is suggested to ensure the clinical prophylactic efficacy and may help reduce the dosage and dose-dependent toxicity comparing with the target of 0.7 mg/L.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3055-3) contains supplementary material, which is available to authorized users.

Primary prophylaxis of invasive fungal infections in patients with haematological malignancies: 2017 update of the recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society for Haematology and Medical Oncology (DGHO)

Immunocompromised patients are at high risk of invasive fungal infections (IFI), in particular those with haematological malignancies undergoing remission-induction chemotherapy for acute myeloid leukaemia (AML) or myelodysplastic syndrome (MDS) and recipients of allogeneic haematopoietic stem cell transplants (HSCT). Despite the development of new treatment options in the past decades, IFI remains a concern due to substantial morbidity and mortality in these patient populations. In addition, the increasing use of new immune modulating drugs in cancer therapy has opened an entirely new spectrum of at risk periods. Since the last edition of antifungal prophylaxis recommendations of the German Society for Haematology and Medical Oncology in 2014, seven clinical trials regarding antifungal prophylaxis in patients with haematological malignancies have been published, comprising 1227 patients. This update assesses the impact of this additional evidence and effective revisions. Our key recommendations are the following: prophylaxis should be performed with posaconazole delayed release tablets during remission induction chemotherapy for AML and MDS (AI). Posaconazole iv can be used when the oral route is contraindicated or not feasible. Intravenous liposomal amphotericin B did not significantly decrease IFI rates in acute lymphoblastic leukaemia (ALL) patients during induction chemotherapy, and there is poor evidence to recommend it for prophylaxis in these patients (CI). Despite substantial risk of IFI, we cannot provide a stronger recommendation for these patients. There is poor evidence regarding voriconazole prophylaxis in patients with neutropenia (CII). Therapeutic drug monitoring TDM should be performed within 2 to 5 days of initiating voriconazole prophylaxis and should be repeated in case of suspicious adverse events or of dose changes of interacting drugs (BIItu). General TDM during posaconazole prophylaxis is not recommended (CIItu), but may be helpful in cases of clinical failure such as breakthrough IFI for verification of compliance or absorption.

Posaconazole Therapeutic Drug Monitoring in a Regional Hospital Setting

BACKGROUND

Posaconazole therapeutic drug monitoring (TDM) is recommended to promote effective antifungal prophylaxis, but its utility has yet to be optimized. Breakthrough invasive fungal infections have been reported with serum concentrations <700 mcg/L, but there is little evidence to determine the optimal serum concentration for efficacy or concentrations associated with toxicity. Challenges for effective monitoring are greater in settings without posaconazole TDM facilities because of the long turnaround time before receipt of results.

METHODS

Thirty-eight TDM episodes were performed on 18 patients in a regional center in Australia during a 30-month period. Australian guidelines recommend a trough serum concentration of ≥700 mcg/L. The response to concentrations below the recommendation threshold (700 mcg/L), the final serum plasma concentration for each patient, and the appropriateness of TDM were evaluated.

RESULTS

A total of 19 (50%) concentrations were recorded to be < 700 mcg/L. Of these 19 concentrations, the drug dose was increased on only 4 occasions. Eleven of 18 patients (61%) had initial concentrations <700 mcg/L, with only 3 (27%) among those achieving final concentration ≥ 700 mcg/L; 5 patients with initial concentrations <700 mcg/L did not have any further TDM testing. Nine of the 18 (50%) patients had a final concentration <700 mcg/L. Five of 7 (71%) patients with initial concentrations ≥700 mcg/L had further TDM with no reasoning documented.

CONCLUSIONS

The results demonstrate a lack of confidence and consistency in ordering, interpreting, and following up posaconazole concentrations. Therefore, the use of TDM should be carefully considered, especially in regional centers. Such settings should consider the practicalities of posaconazole TDM and try to improve the process to ensure consistency and optimization of patient care.

Voriconazole and posaconazole therapeutic drug monitoring: a retrospective study

Background

Therapeutic drug monitoring (TDM) aims to minimize the clinical impact of posaconazole and voriconazole pharmacokinetic variability. However, its benefits on clinical outcomes are still being defined. Additionally, TDM data are limited for posaconazole IV and delayed-release tablet formulations among specific patient populations, including critically ill. The aim of this study was to determine the percentage of therapeutic posaconazole and voriconazole drug levels across all formulations in a real-world clinical setting and elucidate factors affecting attainment of target concentrations.

Methods

This study was a retrospective cohort study conducted at the University of Colorado Hospital between September 2006 and June 2015 that evaluated patients who received posaconazole or voriconazole TDM as part of routine care.

Results

Voriconazole (n = 250) and posaconazole (n = 100) levels were analyzed from 151 patients. Of these, 54% of voriconazole and 69% of posaconazole levels were therapeutic. For posaconazole, 14/38 (37%), 28/29 (97%) and 27/33 (82%) levels were therapeutic for the oral suspension, IV, and delayed-release tablet, respectively. Intravenous and delayed-release tablet posaconazole were 20 fold (p < 0.01) and sevenfold (p = 0.002) more likely than the oral suspension to achieve a therapeutic level. Subsequent levels were more likely to be therapeutic after dose adjustments (OR 3.31; 95% CI 1.3–8.6; p = 0.02), regardless of timing of initial non-therapeutic level. In a multivariable logistic regression analysis, no characteristics were independently predictive of therapeutic voriconazole levels and only absence of H2RA/PPI use was independently predictive of therapeutic posaconazole levels. There was no correlation between survival and therapeutic drug levels for either voriconazole (p = 0.67) or posaconazole (p = 0.50).

Conclusions

A high percentage of drug levels did not achieve TDM targets for voriconazole and posaconazole oral suspension, supporting the need for routine TDM for those formulations. The utility of TDM for the IV and delayed-release tablet formulations of posaconazole is less apparent.

Comparing Azole Plasma Trough Levels in Lung Transplant Recipients: Percentage of Therapeutic Levels and Intrapatient Variability

BACKGROUND

This study compared therapeutic azole plasma trough levels (APL) of the azole antimycotics itraconazole (ITR), voriconazole (VOR), and posaconazole (POS) in lung transplant recipients and analyzed the influencing factors. In addition, intrapatient variability for each azole was determined.

METHODS

From July 2012 to July 2015, 806 APL of ITR, VOR, posaconazole liquid (POS-Liq), and posaconazole tablets (POS-Tab) were measured in 173 patients of the Munich Lung Transplantation Program. Therapeutic APL were defined as follows: ITR, ≥700 ng/mL; VOR, 1000-5500 ng/mL; and POS, ≥700 ng/mL (prophylaxis) and ≥1000 ng/mL (therapy).

RESULTS

VOR and POS-Tab reached the highest number of therapeutic APL, whereas POS-Liq showed the lowest percentage (therapy: ITR 50%, VOR 70%, POS-Liq 38%, and POS-Tab 82%; prophylaxis: ITR 62%, VOR 85%, POS-Liq 49%, and POS-Tab 76%). Risk factors for subtherapeutic APL of all azoles were the azole dose (ITR, P < 0.001; VOR, P = 0.002; POS-Liq, P = 0.006) and age over 60 years (ITR, P = 0.003; VOR, P = 0.002; POS-Liq, P = 0.039; POS-Tab, P < 0.001). Cystic fibrosis was a significant risk factor for subtherapeutic APL for VOR and POS-Tab (VOR, P = 0.002; POS-Tab, P = 0.005). Double lung transplantation (LTx) was significantly associated with less therapeutic APL for VOR and POS-Liq (VOR, P = 0.030; POS-Liq, P < 0.001). Concomitant therapy with 80 mg pantoprazole led to significantly fewer therapeutic POS APL as compared to 40 mg (POS-Liq, P = 0.015; POS-Tab, P < 0.001). VOR displayed the greatest intrapatient variability (46%), whereas POS-Tab showed the lowest (32%).

CONCLUSIONS

Our study showed that VOR and POS-Tab achieve the highest percentage of therapeutic APL in patients with LTx; POS-Tab showed the lowest intrapatient variability. APL are significantly influenced by azole dose, age, cystic fibrosis, type of LTx, and comedication with proton-pump inhibitors. Considering the high number of subtherapeutic APL, therapeutic drug monitoring should be integrated in the post-LTx management.

Posaconazole Plasma Concentrations on Days Three to Five Predict Steady-State Levels

Low posaconazole plasma concentrations (PPCs) have been associated with breakthrough invasive fungal infections. We assessed the correlation between pre-steady-state PPCs (obtained between days 3 and 5) and PPCs obtained during steady state in 48 patients with underlying hematological malignancies receiving posaconazole oral-solution prophylaxis. Pre-steady-state PPCs correlated significantly with PPCs obtained at steady state (Spearman r = 0.754; P < 0.001). Receiver operating characteristic (ROC) curve analysis of pre-steady-state PPCs revealed an area under the curve (AUC) of 0.884 (95% confidence interval [CI], 0.790 to 0.977) for predicting satisfactory PPCs at steady state.

Comparison of clinical pharmacology of voriconazole and posaconazole

Despite greater knowledge and possibilities in pharmacotherapy, fungal infections remain a challenge for clinicians. As the population of immunocompromised patients and those treated for their hematologic ailments increases, the number of fungal infections grows too. This is why there is still a quest for new antifungal drugs as well as for optimization of pharmacotherapy with already registered pharmaceutics.

Voriconazole and posaconazole are broad-spectrum, new generation, triazole antifungal agents. The drugs are used in the pharmacotherapy of invasive aspergillosis, Candida and Fusarium infections. Voriconazole is also used in infections caused by Scedosporium. Posaconazole is used in the treatment of coccidioidomycosis and chromoblastomycosis. Besides some similarities, the two mentioned drugs also show differences in therapeutic indications, pharmacokinetics (mainly absorption and metabolism), frequency and severity of adverse drug reactions, drug–drug interactions and dosage. As both of the drugs are used in the treatment of invasive fungal infections in adults and children, detailed knowledge of the clinical pharmacology of antifungal agents is the main factor in pharmacotherapy optimization in treatment of fungal infections.

The goal of the article is to present and compare the clinical pharmacology of voriconazole and posaconazole as well as to point out the indications and contraindications of using the drugs, determine factors influencing their pharmacotherapy, and provide information that might be helpful in the treatment of fungal infections.

Antifungal prophylaxis: why, what and how?

41st Annual Meeting of the European Society for Blood and Marrow Transplantation (EBMT 2015), Istanbul, Turkey, 22-25 March 2015 The European Society for Blood and Marrow Transplantation (EBMT) is the leading scientific society for professionals involved in hematopoietic stem-cell transplantation (HSCT) and represents 563 transplant centers from 57 countries within and outside Europe. Each year, the EBMT Annual Meeting brings together over 4,500 scientists, physicians, nurses, biologists, technicians and patients to discuss scientific data that build on past achievements in the field of HSCT. The procedure offers the chance of long-term remission of hematological and lymphoid cancers, but patients are at increased risk of serious infections, especially after allogeneic HSCT. These infections include the invasive fungal infections that were among the important topics discussed during EBMT 2015.

Prevention of invasive fungal infections in immunocompromised patients: the role of delayed-release posaconazole

Posaconazole is a triazole antifungal agent that has broad-spectrum activity against many yeasts and filamentous fungi, including Candida species, Cryptococcus neoformans, Aspergillus species, and Zygomycetes. This drug has been approved for the prevention of invasive fungal infections in patients with neutropenia and for the treatment of invasive fungal infections in hematopoietic stem cell transplant recipients with graft-versus-host disease. Studies on the clinical efficacy, safety, tolerability, and cost-effectiveness of posaconazole therapy were performed using the oral suspension form of the drug. Pharmacokinetic studies have found that the oral suspension form of posaconazole has problemeatic bioavailability: its absorption is affected by concomitant medication and food. This article discusses the pharmacokinetic properties of the newly developed posaconazole delayed-release tablet formulation and reviews the efficacy, safety, and cost-effectiveness of both the oral suspension and the new tablet formulation. In conclusion, the posaconazole tablet formulation has better systemic bioavailability, thereby enabling once-daily administration and better absorption in the presence of concomitant medication and food. However, well-designed clinical studies are needed to evaluate the use of the tablet formulation in real-life settings.

Consensus guidelines for optimising antifungal drug delivery and monitoring to avoid toxicity and improve outcomes in patients with haematological malignancy, 2014

Antifungal agents may be associated with significant toxicity or drug interactions leading to sub-therapeutic antifungal drug concentrations and poorer clinical outcomes for patients with haematological malignancy. These risks may be minimised by clinical assessment, laboratory monitoring, avoidance of particular drug combinations and dose modification. Specific measures, such as the optimal timing of oral drug administration in relation to meals, use of pre-hydration and electrolyte supplementation may also be required. Therapeutic drug monitoring (TDM) of antifungal agents is warranted, especially where non-compliance, non-linear pharmacokinetics, inadequate absorption, a narrow therapeutic window, suspected drug interaction or unexpected toxicity are encountered. Recommended indications for voriconazole and posaconazole TDM in the clinical management of haematology patients are provided. With emerging knowledge regarding the impact of pharmacogenomics upon metabolism of azole agents (particularly voriconazole), potential applications of pharmacogenomic evaluation to clinical practice are proposed.

Retrospective Comparison of Posaconazole Levels in Patients Taking the Delayed-Release Tablet versus the Oral Suspension

While posaconazole prophylaxis decreases the risk of invasive fungal infection compared to fluconazole, low bioavailability of the oral-suspension formulation limits its efficacy. A new delayed-release tablet formulation demonstrated an improved pharmacokinetic profile in healthy volunteers. However, serum levels for the two formulations have not been compared in clinical practice. This study compared achievement of therapeutic posaconazole levels in patients taking the delayed-release tablet to those taking the oral suspension. This retrospective cohort study included 93 patients initiated on posaconazole between 2012 and 2014 and had at least one serum posaconazole level measured. The primary measure was the proportion of patients achieving an initial therapeutic level (>700 ng/ml). An initial therapeutic posaconazole level was seen in 29 of 32 (91%) patients receiving tablets and 37 of 61 (61%) patients receiving suspension (P = 0.003). Among patients with a steady-state level measured 5 to 14 days after initiation, a therapeutic level was observed in 18 of 20 (90%) patients receiving tablets and 25 of 43 (58%) patients receiving suspension (P = 0.01). In these patients, the median posaconazole level of the tablet cohort (1655 ng/ml) was twice that of the suspension cohort (798 ng/ml) (P = 0.004). In this cohort study, the improved bioavailability of delayed-release posaconazole tablets translates into a significantly higher proportion of patients achieving therapeutic serum levels than in the cohort receiving the oral suspension. The results of this study strongly support the use of delayed-release tablets over suspension in patients at risk for invasive fungal infection.

The difficult management of disseminated Sporothrix brasiliensis in a patient with advanced AIDS

Sporotrichosis is an infection caused by a dimorphic fungus of the Sporothrix schenckii complex. Host immunity is an important factor in the clinical manifestations of the disease. Deeply immunocompromised individuals, especially those infected with the Human Immunodeficiency Virus (HIV) and T CD4 counts < 350 cells/ul lymphocytes, may present with the systemic form of sporotrichosis. This report describes a case of disseminated sporotrichosis caused by S. brasiliensis in a patient with advanced AIDS. The skin, lungs, bones and central nervous system were affected. Medical treatment involved the administration of amphotericin B, terbinafine, itraconazole and posaconazole. Posaconazole was associated with the best clinical response and clearing of the fungus from the central nervous system.

Successful long-term management of invasive cerebral fungal infection following liver transplantation

Central nervous system (CNS) infections after liver transplantation may be fungal in aetiology, with involvement from either common organisms such as Cryptococcus neoformans and Aspergillus spp. as well as less common organisms, such as the Mucorales and Scedosporium spp. Although the mortality of CNS fungal infections was nearly 100% in early series, more recent data has suggested that good outcomes can be achieved. This may be due to both improved diagnostic capabilities, such as the ability to obtain fungal susceptibilities and therapeutic drug levels, and improved therapeutic options, such as the newer triazoles- voriconazole and posaconazole. Due to improved outcomes, issues have now arisen around the long-term tolerability of these agents. The following two cases of invasive cerebral fungal infections following liver transplantation, one with Aspergillus flavus, and the other with Scedosporium boydii/apiospermum highlight the success that can be seen with the modern management of a previously fatal diagnosis. In particular, we highlight the issues around therapeutic monitoring and discontinuation of therapy.

Toward a personalized medicine approach to the management of inflammatory bowel disease

The medical management of inflammatory bowel disease (IBD) is evolving toward a personalized medicine-based model. Modern therapeutic algorithms that feature use of tumor necrosis factor (TNF) antagonists in combination with immunosuppressive are highly effective when initiated in high-risk patients early in the course of disease. Defined targets that guide intensification of therapy are critical interventions. In this model, therapy is optimized through appropriate pretreatment testing, therapeutic drug monitoring, and patient-based monitoring strategies. This review discusses the current application of personalized medicine to the management of IBD.