Review of the safety, tolerability, and drug interactions of the new antifungal agents caspofungin and voriconazole

A new humanized antibody is effective against pathogenic fungi in vitro

Invasive fungal infections mainly affect patients undergoing transplantation, surgery, neoplastic disease, immunocompromised subjects and premature infants, and cause over 1.5 million deaths every year. The most common fungi isolated in invasive diseases are Candida spp., Cryptococcus spp., and Aspergillus spp. and even if four classes of antifungals are available (Azoles, Echinocandins, Polyenes and Pyrimidine analogues), the side effects of drugs and fungal acquired and innate resistance represent the major hurdles to be overcome. Monoclonal antibodies are powerful tools currently used as diagnostic and therapeutic agents in different clinical contexts but not yet developed for the treatment of invasive fungal infections. In this paper we report the development of the first humanized monoclonal antibody specific for β-1,3 glucans, a vital component of several pathogenic fungi. H5K1 has been tested on C. auris, one of the most urgent threats and resulted efficient both alone and in combination with Caspofungin and Amphotericin B showing an enhancement effect. Our results support further preclinical and clinical developments for the use of H5K1 in the treatment of patients in need.

Free circulating mircoRNAs support the diagnosis of invasive aspergillosis in patients with hematologic malignancies and neutropenia

Fungal infections represent a worrisome complication in hematologic cancer patients and in the absence of disease specific symptoms, it is important to establish new biological indicators, which can be used during mould-active prophylaxis. Recently, miRNAs have appeared as candidate diagnostic and prognostic markers of several diseases. A pilot clinical study was performed to evaluate the diagnostic utility of 14 microRNAs which can be related to invasive fungal infections. Based on our data miR-142-3p, miR-142-5p, miR-26b-5p and miR-21-5p showed significant overexpression (p < 0.005) due to invasive aspergillosis in hemato-oncology patients with profound neutropenia. A tetramiR assay was designed to monitor peripheral blood specimens. Optimal cut-off was estimated by using the median value (fold change 1.1) of the log10 transformed gene expressions. The biomarker panel was evaluated on two independent sample cohorts implementing different antimicrobial prophylactic strategies. The receiver operating characteristic analysis with area under the curve proved to be 0.97. Three miRNAs (miR-142-5p, miR-142-3p, miR-16-5p) showed significant expression alterations in episodes with sepsis. In summary, the tetramiR assay proved to be a promising diagnostic adjunct with sufficient accuracy and sensitivity to trace invasive aspergillosis in hemato-oncology patients.

Kolliphor® HS 15-cyclodextrin Complex for the Delivery of Voriconazole: Preparation, Characterization, and Antifungal Activity

BACKGROUND

This study aimed to reduce the amount of sulfobutylether-β-cyclodextrin (SBECD) used in the marketed voriconazole injections to meet the clinical needs of patients with moderate-to-severe renal impairment (creatinine clearance rate <50 mL/min).

OBJECTIVE

This study found that the surfactant Kolliphor® HS 15 (HS 15) and SBECD had significant synergistic effects on solubilizing voriconazole, and a novel voriconazole complex delivery system (VRC-CD/HS 15) was established.

METHODS

The complex system was characterized, and its antifungal activity was studied by dynamic light scattering, dialysis bag method, disk diffusion, and broth microdilution.

RESULTS

Compared with the control, its encapsulation efficiency (90.07±0.48%), drug loading (7.37±0.25%) and zeta potential (-4.36±1.37 mV) were increased by 1.54%, 41.19%, and 296.36%, respectively; its average particle size (13.92±0.00 nm) was reduced by 15.69%, so the complex system had better stability. Simultaneously, its drug release behavior was similar to that of the control, and it was a first-order kinetic model. Antifungal studies indicated that the complex system had noticeable antifungal effects. With the increase of drug concentration, the inhibition zone increased. The minimum inhibitory concentrations of the complex system against Cryptococcus neoformans, Aspergillus niger and Candida albicans were 0.0313 μg/mL, 1 μg/mL and 128 μg/mL, respectively.

CONCLUSION

It showed a significant inhibitory effect on C. neoformans and had a visible therapeutic effect on Kunming mice infected with C. neoformans. Consequently, VRC-CD/HS 15 had better physicochemical properties and still had an apparent antifungal effect, and was promising as a potential alternative drug for clinical application.

Management of bacterial and fungal infections in end stage liver disease and liver transplantation: Current options and future directions

Patients with liver cirrhosis are susceptible to infections due to various mechanisms, including abnormalities of humoral and cell-mediated immunity and occurrence of bacterial translocation from the intestine. Bacterial infections are common and represent a reason for progression to liver failure and increased mortality. Fungal infections, mainly caused by Candida spp., are often associated to delayed diagnosis and high mortality rates. High level of suspicion along with prompt diagnosis and treatment of infections are warranted. Bacterial and fungal infections negatively affect the outcomes of liver transplant candidates and recipients, causing disease progression among patients on the waiting list and increasing mortality, especially in the early post-transplant period. Abdominal, biliary tract, and bloodstream infections caused by Gram-negative bacteria [e.g., Enterobacteriaceae and Pseudomonas aeruginosa (P. aeruginosa)] and Staphylococcus spp. are commonly encountered in liver transplant recipients. Due to frequent exposure to broad-spectrum antibiotics, invasive procedures, and prolonged hospitalizations, these patients are especially at risk of developing infections caused by multidrug resistant bacteria. The increase in antimicrobial resistance hampers the choice of an adequate empiric therapy and warrants the knowledge of the local microbial epidemiology and the implementation of infection control measures. The main characteristics and the management of bacterial and fungal infections in patients with liver cirrhosis and liver transplant recipients are presented.

Echinocandins for management of invasive candidiasis in patients with liver disease and liver transplantation

Candida species remains one of the most important causes of opportunistic infections worldwide. Invasive candidiasis (IC) is associated with considerable morbidity and mortality in liver disease (LD) patients if not treated promptly. Echinocandins are often recommended as a first-line empirical treatment for managing IC and can especially play a critical role in managing IC in LD patients. However, advanced LD patients are often immunocompromised and critically ill. Hence altered pharmacokinetics, drug interactions as well as tolerance issues of antifungal treatments are a concern in these patients. This comprehensive review examines the epidemiology, risk factors and diagnosis of IC in patients with LD and evaluates differences between three available echinocandins for treating this group of patients.

Pharmacokinetics of antifungal drugs: practical implications for optimized treatment of patients

Introduction

Because of the high mortality of invasive fungal infections (IFIs), appropriate exposure to antifungals appears to be crucial for therapeutic efficacy and safety.

Materials and methods

This review summarises published pharmacokinetic data on systemically administered antifungals focusing on co-morbidities, target-site penetration, and combination antifungal therapy.

Conclusions and discussion

Amphotericin B is eliminated unchanged via urine and faeces. Flucytosine and fluconazole display low protein binding and are eliminated by the kidney. Itraconazole, voriconazole, posaconazole and isavuconazole are metabolised in the liver. Azoles are substrates and inhibitors of cytochrome P450 (CYP) isoenzymes and are therefore involved in numerous drug–drug interactions. Anidulafungin is spontaneously degraded in the plasma. Caspofungin and micafungin undergo enzymatic metabolism in the liver, which is independent of CYP. Although several drug–drug interactions occur during caspofungin and micafungin treatment, echinocandins display a lower potential for drug–drug interactions. Flucytosine and azoles penetrate into most of relevant tissues. Amphotericin B accumulates in the liver and in the spleen. Its concentrations in lung and kidney are intermediate and relatively low myocardium and brain. Tissue distribution of echinocandins is similar to that of amphotericin. Combination antifungal therapy is established for cryptococcosis but controversial in other IFIs such as invasive aspergillosis and mucormycosis.

In vitro assessment of non-irritant microemulsified voriconazole hydrogel system

Research was aimed on microemulsion-based hydrogel for voriconazole. Oleic acid and isopropyl myristate as lipid phases; tween 20: tween 80 as surfactants and PEG600 as cosurfactant were selected to formulate voriconazole microemulsions. The promising microemulsions in terms of zeta potential, pH, viscosity, and drug release were selected and developed into hydrogels using carbopol 934. Resulting microemulsion-based hydrogel (MBH) of voriconazole were evaluated for in vitro diffusion and ex vivo permeation. Antifungal potentials of MBH were assessed against selected fungal strains. Optimal MBH formulations, O6 and O8 had displayed their antifungal potentials with enlarged zone of inhibition against selected fungal strains.

Development of an inhaled controlled release voriconazole dry powder formulation for the treatment of respiratory fungal infection

The present research aimed to develop and characterize a sustained release dry powder inhalable formulation of voriconazole (VRZ) for invasive pulmonary aspergillosis. The developed formulations were studied for their in vitro release profile, aerosol, and physicochemical properties as well as interactions with lung epithelia in terms of toxicity and transport/uptake. VRZ and VRZ loaded poly lactide microparticles (VLM) were prepared by aqueous/organic cosolvent and organic spray drying, respectively. Powders were characterized using laser diffraction, differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), dynamic vapor sorption (DVS), and electron microscopy. Aerosol performance was evaluated using an RS01 dry powder inhaler and in vitro cascade impaction. Uptake across Calu-3 lung epithelia was studied, using aerosol deposition of the powder onto cells cultured in an air interface configuration, and compared to dissolution using a conventional dialysis membrane. Additionally, toxicity of VRZ and VLM and the potential impact of transmembrane proteins on uptake were investigated. The particle size and the aerosol performance of spray-dried VRZ and VLM were suitable for inhalation purposes. VRZ exhibited a median volume diameter of 4.52 ± 0.07 μm while VLM exhibited 2.40 ± 0.05 μm. Spray-dried VRZ was crystalline and VLM amorphous as evaluated by DSC and XRPD, and both powders exhibited low moisture sorption between 0 and 90% RH (<1.2% w/w) by DVS. The fine particle fraction (FPF) (% aerosol <5 μm) for the VRZ was 20.86 ± 1.98% while the VLM showed significantly improved performance (p < 0.01) with an FPF of 43.56 ± 0.13%. Both VRZ and VLM were not cytotoxic over a VRZ concentration range of 1.2 nM to 30 μM, and the VLM particles exhibited a sustained release over 48 h after being deposited on the Calu-3 cell line or via conventional dialysis-based dissolution measurements. Lastly, VRZ exhibited polarized transport across epithelia with basal to apical transport being slower than apical to basal. Influx and efflux transports may also play a role as transport was altered in the presence of a number of inhibitors. This study has established an inhalable and sustained release powder of VRZ for targeting invasive pulmonary aspergillosis.

Geneva cocktail for cytochrome p450 and P-glycoprotein activity assessment using dried blood spots

The suitability of the capillary dried blood spot (DBS) sampling method was assessed for simultaneous phenotyping of cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp) using a cocktail approach. Ten volunteers received an oral cocktail capsule containing low doses of the probes bupropion (CYP2B6), flurbiprofen (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), midazolam (CYP3A), and fexofenadine (P-gp) with coffee/Coke (CYP1A2) on four occasions. They received the cocktail alone (session 1), and with the CYP inhibitors fluvoxamine and voriconazole (session 2) and quinidine (session 3). In session 4, subjects received the cocktail after a 7-day pretreatment with the inducer rifampicin. The concentrations of probes/metabolites were determined in DBS and plasma using a single liquid chromatography–tandem mass spectrometry method. The pharmacokinetic profiles of the drugs were comparable in DBS and plasma. Important modulation of CYP and P-gp activities was observed in the presence of inhibitors and the inducer. Minimally invasive one- and three-point (at 2, 3, and 6 h) DBS-sampling methods were found to reliably reflect CYP and P-gp activities at each session.

Posaconazole Pharmacokinetics, Safety, and Tolerability in Subjects With Varying Degrees of Chronic Renal Disease

Posaconazole is a triazole antifungal in development for the treatment of invasive fungal infections. The authors evaluated the pharmacokinetics and safety of posaconazole in healthy subjects and in those with mild (CL(CR) = 50-80 mL/min), moderate (CL(CR) = 20-49 mL/min), and severe chronic renal disease (CL(CR) <20 mL/min; receiving outpatient hemodialysis) (n = 6/group). Subjects received one 400-mg dose of posaconazole oral suspension with a standardized high-fat breakfast. For hemodialysis-dependent subjects, this dose was given on a nonhemodialysis day, and a second 400-mg dose was given 6 hours before hemodialysis. Blood samples were collected before dose and up to 120 hours postdose. For hemodialysis-dependent subjects following the second dose, additional samples (predialyzed and postdialyzed) were collected before, during, and after dialysis. There was no correlation between posaconazole pharmacokinetics and mild to moderate renal disease; the slopes of the linear regressions for creatinine clearance versus posaconazole AUC, C(max), CL/F, and t1/2 values were not significantly different from zero (P > .130). Mean CL/F values before and during hemodialysis were comparable. Furthermore, the difference in the predialyzed and postdialyzed posaconazole concentrations was only approximately 3%, supporting that posaconazole was not removed by hemodialysis. Protein binding was similar in all groups (approximately 98%) and was unaffected by hemodialysis. Posaconazole was generally well tolerated. One patient had elevated liver function test results that were not present at baseline and were thought to be possibly related to posaconazole. Results of this single-dose study indicate that dosage adjustments for patients with varying degrees of renal disease are not required.

Lack of Pharmacokinetic Interaction Between Anidulafungin and Tacrolimus

The safety and pharmacokinetics of anidulafungin coadministered with tacrolimus were investigated using a single-sequence, open-label design. Healthy volunteers received 5 mg tacrolimus orally on days 1 and 13 of the study. Anidulafungin (200 mg) was administered intravenously on day 4, followed by 100-mg doses on days 5 through 13. Key pharmacokinetic parameters, including C(max), AUC, t((1/2)), CL, and V(ss), were derived from concentration-time data. The 90% confidence intervals (CIs) of the ratios of mean pharmacokinetic parameters of anidulafungin plus tacrolimus to each drug alone were well within the 80% to 125% bioequivalence range, indicating no pharmacokinetic interaction. This ratio was 101.6 (90% CI: 92.77-111.22) for tacrolimus AUC(0-infinity) and 107.2 (90% CI: 105.1-109.4) for anidulafungin AUC(ss). The 2 drugs were well tolerated, and no drug-related serious adverse events were reported. Because of its lack of pharmacokinetic interaction with key immunosuppressive agents, anidulafungin is an important option for the prevention and treatment of invasive fungal infections in transplant recipients.

Population pharmacokinetics of escalating doses of caspofungin in a phase II study of patients with invasive aspergillosis

Caspofungin (CAS) is approved for second-line management of proven or probable invasive aspergillosis at a dose of 50 mg once daily (QD). Preclinical and limited clinical data support the concept of the dose-dependent antifungal efficacy of CAS with preservation of its favorable safety profile. Little is known, however, about the pharmacokinetics (PKs) of higher doses of CAS in patients. In a formal multicenter phase II dose-escalation study, CAS was administered as a 2-h infusion at doses ranging from 70 to 200 mg QD. CAS PK sampling (n = 468 samples) was performed on day 1 and at peak and trough time points on days 4, 7, 14, and 28 (70 mg, n = 9 patients; 100 mg, n = 8 patients; 150 mg, n = 9 patients; 200 mg, n = 20 patients; total, n = 46 patients). Drug concentrations in plasma were measured by liquid chromatography tandem mass spectroscopy. Population pharmacokinetic analysis (PopPK) was performed using NONMEM (version 7) software. Model evaluation was performed using bootstrap analysis, prediction-corrected visual predictive check (pcVPC), as well as standardized visual predictive check (SVPC). The four investigated dose levels showed no difference in log-transformed dose-normalized trough levels of CAS (analysis of variance). CAS concentration data fitted best to a two-compartment model with a proportional-error model, interindividual variability (IIV) fitted best on clearance (CL), central and peripheral volume of distribution (V(1) and V(2), respectively) covariance fitted best on CL and V(1), interoccasion variability (IOV) fitted best on CL, and body weight fitted best as a covariate on CL and V(1) (CL, 0.411 liters/h ± 29% IIV; IOV on CL, 16%; V(1), 5.785 liters ± 29% IIV; intercompartmental clearance, 0.843 liters/h; V2, 6.53 liters ± 67% IIV). None of the other examined covariates (dose level, gender, age, serum bilirubin concentration, creatinine clearance) improved the model further. Bootstrap results showed the robustness of the final PopPK model. pcVPC and SVPC showed the predictability of the model and further confirmed the linear PKs of CAS over the dosage range of 70 to 200 mg QD. On the basis of the final model, geometric mean simulated peak plasma levels at steady state ranged from 13.8 to 39.4 mg/liter (geometric coefficient of variation, 31%), geometric mean trough levels ranged from 4.2 to 12.0 mg/liter (49%), and geometric mean areas under the concentration-time curves ranged from 170 to 487 mg · h/liter (34%) for the dosage range of 70 to 200 mg QD. CAS showed linear PKs across the investigated dosage range of 70 to 200 mg QD. Drug exposure in the present study population was comparable to that in other populations. (This study has been registered with the European Union Drug Regulating Authorities Clinical Trials website under registration no. 2006-001936-30 and at ClinicalTrials.gov under registration no. NCT00404092.).

Phase II dose escalation study of caspofungin for invasive Aspergillosis

Our objective was to evaluate the maximum tolerated dose of caspofungin for invasive aspergillosis (IA). The safety and pharmacokinetics of escalating dosages of caspofungin were investigated in IA. Eight patients each received caspofungin 70, 100, 150, or 200 mg once a day (QD). Dose-limiting toxicity (DLT) was defined as the same non-hematological treatment-related adverse event of grade ≥ 4 in 2 of 8 patients or ≥ 3 in 4 of 8 patients in a cohort. A total of 46 patients (median age, 61 years; 21 female; 89% with hematological malignancies) received caspofungin (9, 8, 9, and 20 patients in the 70-, 100-, 150-, and 200-mg cohorts) for a median of 24.5 days. Plasma pharmacokinetics were linear across the investigated dosages and followed a two-compartment model, with weight as the covariate on clearance and sex as the covariate on central volume of distribution. Simulated peak plasma concentrations at steady state ranged from 14.2 to 40.6 mg/liter (28%), trough concentrations from 4.1 to 11.8 mg/liter (58%), and area under the concentration-time curve from 175 to 500 mg/liter/h (32%) (geometric mean, geometric coefficient of variation). Treatment was well tolerated without dose-limiting toxicity. The rate of complete or partial responses was 54.3%, and the overall mortality at 12-week follow-up was 28.3%. In first-line treatment of invasive aspergillosis, daily doses of up to 200 mg caspofungin were well tolerated and the maximum tolerated dose was not reached. Pharmacokinetics was linear. Response rates were similar to those previously reported for voriconazole and liposomal amphotericin.

Short native antimicrobial peptides and engineered ultrashort lipopeptides: similarities and differences in cell specificities and modes of action

Due to the rapid emergence of resistant microbes to the currently available antibiotics, cationic antimicrobial peptides have attracted considerable interest as a possible new generation of anti-infective compounds. However, low cost development for therapeutic or industrial purposes requires, among other properties, that the peptides will be small and with simple structure. Therefore, considerable research has been devoted to optimizing peptide length combined with a simple design. This review focuses on the similarities and differences in the mode of action and target cell specificity of two families of small peptides: the naturally occurring temporins from the skin of amphibia and the engineered ultrashort lipopeptides. We will also discuss the finding that acylation of cationic peptides results in molecules with a more potent spectrum of activity and a higher resistance to proteolytic degradation. Conjugation of fatty acids to linear native peptide sequences is a powerful strategy to engineer novel successful anti-infective drugs.

Invasive mould infections: a multi-disciplinary update

Systemic fungal infections remain a significant cause of mortality in neutropenic and immunocompromised patients, despite advances in their diagnosis and treatment. The incidence of such infections is rising due to the use of intensive chemotherapy regimens in patients with solid tumours or haematological cancers, the increasing numbers of allogeneic haematopoietic stem cell and solid organ transplants, and the use of potent immunosuppressive therapy in patients with autoimmune disorders. In addition, the epidemiology of systemic fungal infections is changing, with atypical species such as Aspergillus terreus and zygomycetes becoming more common. Treatment has traditionally focused on empirical therapy, but targeted pre-emptive therapy in high-risk patients and prophylactic antifungal treatment are increasingly being adopted. New treatments, including lipid formulations of amphotericin B, second-generation broad-spectrum azoles, and echinocandins, offer effective antifungal activity with improved tolerability compared with older agents; the potential impact of these treatments is reflected in their inclusion in current treatment and prophylaxis guidelines. New treatment strategies, such as aerosolized lipid formulations of amphotericin B, may also reduce the burden of mortality associated with systemic fungal infections. The challenge is to identify ways of coupling potentially effective treatments with early and reliable identification of patients at highest risk of infection.

Recent approaches to antifungal therapy for invasive mycoses

Invasive fungal infections with primary and opportunistic mycoses have become increasingly common in recent years and pose a major diagnostic and therapeutic challenge. They represent a major area of concern in today's medical fraternity. The occurrence of invasive fungal diseases, particularly in AIDS and other immunocompromised patients, is life-threatening and increases the economic burden. Apart from the previously known polyenes and imidazole-based azoles, newly discovered triazoles and echinocandins are more effective in terms of specificity, yet some immunosuppressed hosts are difficult to treat. The main reasons for this include antifungal resistance, toxicity, lack of rapid and microbe-specific diagnoses, poor penetration of drugs into sanctuary sites, and lack of oral or intravenous preparations. In addition to combination antifungal therapy, other novel antimycotic treatments such as calcineurin signaling pathway blockers and vaccines have recently emerged. This review briefly summarizes recent developments in the pharmacotherapeutic treatment of invasive fungal infections.

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).

[Tolerance of caspofungin in intensive care unit: a prospective study]

OBJECTIVE

Caspofungin has shown efficacy and very low toxicity in empirical antifungal therapy in refractory invasive Aspergillus infections and invasive candidiasis in neutropenic (or non) patients. To date, there is no data on tolerability of caspofungin in ICU patients. The aim of this study was to evaluate caspofungine tolerability in critical care patients.

PATIENTS AND METHOD

Over a 36-month period, 1430 patients were admitted in a general intensive care unit. All patients data were collected in a prospective database. All the clinical or biological side effects reported in the multicentric studies were required. The patients were laminated in two groups, according to the initial hepatic function.

RESULTS

Seventy-three patients were treated with caspofungin (5.1%) and 58% were immunocompromised. Immunosuppression was due to acute leukemia (30%), solid organ transplant (20%) or other causes of immunosuppression. In this group, SAPS2 was higher (51+/-20 versus 44+/-20; p<0.05) as mortality rate was (60% versus 23%). More than 90% of patients were ventilated and 55% needed extrarenal therapy. Caspofungin treatment was initiated for aspergillosis in 12 patients, candidiasis in 33 patients and others indications. Partial or complete response to treatment was 72%. Median duration of caspofungin administration was 11 days, no liver dysfunction or acute renal failure due to caspofungin was reported whatever initial liver function was.

CONCLUSION

This prospective open study demonstrate the very low toxicity of caspofungin even in critical care patients.

Measurement of voriconazole in serum and plasma

OBJECTIVES

Voriconazole is an antifungal agent structurally related to fluconazole. While regular drug monitoring is not indicated in most patients, it may help guide dosing in patients with reduced hepatic/renal function, on concurrent therapy with drugs that affect CYP2C9, with altered CYP2C9 genotypes, or during adverse drug reactions. Here we describe an HPLC method for determination of voriconazole.

METHODS

Samples, calibrators and controls were extracted using a liquid/liquid extraction. Chromatographic separation achieved using gradient solvent delivery with detection at 254 nm with a run time of 10 min. Concentration was calculated by comparison of peak height ratio of the drug with that of internal standard (IS) against a standard curve.

RESULTS

The assay is linear from 0.29 to 57 micromol/L (0.1-20 microg/mL) shows good linearity (y=0.98x+0.36, r(2)=0.9978). The assay has inter- and intra-day precisions of <10%. The stability of the drugs in specimens was tested for up to 7 days at room temperature, for 30 days frozen at -20 degrees C, and through 3 freeze-thaw cycles and was found to be stable under those conditions.

CONCLUSIONS

This describes a robust method for the determination of voriconazole in serum and plasma.

Drug-drug interactions of antifungal agents and implications for patient care

Drug interactions in the gastrointestinal tract, liver and kidneys result from alterations in pH, ionic complexation, and interference with membrane transport proteins and enzymatic processes involved in intestinal absorption, enteric and hepatic metabolism, renal filtration and excretion. Azole antifungals can be involved in drug interactions at all the sites, by one or more of the above mechanisms. Consequently, azoles interact with a vast array of compounds. Drug-drug interactions associated with amphotericin B formulations are predictable and result from the renal toxicity and electrolyte disturbances associated with these compounds. The echinocandins are unknown cytochrome P450 substrates and to date are relatively devoid of significant drug-drug interactions. This article reviews drug interactions involving antifungal agents that affect other agents and implications for patient care are highlighted.

Resistance to echinocandin-class antifungal drugs

Invasive fungal infections cause morbidity and mortality in severely ill patients, and limited drug classes restrict treatment choices. The echinocandin drugs are the first new class of antifungal compounds that target the fungal cell wall by blocking beta-1,3-d-glucan synthase. Elevated MIC values with occasional treatment failure have been reported for strains of Candida. Yet, an uncertain correlation exists between clinical failure and elevated MIC values for the echinocandin drugs. Fungi display several adaptive physiological mechanisms that result in elevated MIC values. However, resistance to echinocandin drugs among clinical isolates is associated with amino acid substitutions in two "hot-spot" regions of Fks1, the major subunit of glucan synthase. The mutations, yielding highly elevated MIC values, are genetically dominant and confer cross-resistance to all echinocandin drugs. Prominent Fks1 mutations decrease the sensitivity of glucan synthase for drug by 1000-fold or more, and strains harboring such mutations may require a concomitant increase in drug to reduce fungal organ burdens in animal infection models. The Fks1-mediated resistance mechanism is conserved in a wide variety of Candida spp. and can account for intrinsic reduced susceptibility of certain species. Fks1 mutations confer resistance in both yeasts and moulds suggesting that this mechanism is pervasive in the fungal kingdom.

Voriconazole : a review of its use in the management of invasive fungal infections

Voriconazole (VFEND), a synthetic second-generation, broad-spectrum triazole derivative of fluconazole, inhibits the cytochrome P450 (CYP)-dependent enzyme 14-alpha-sterol demethylase, thereby disrupting the cell membrane and halting fungal growth. In the US, intravenous and/or oral voriconazole is recommended in adults for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, disseminated infections caused by Candida spp., oesophageal candidiasis, and in patients with scedosporiosis and fusariosis who are refractory to or intolerant of other antifungal therapy. In Europe, intravenous and/or oral voriconazole is recommended in adults and paediatric patients of at least 2 years of age for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, fluconazole-resistant serious invasive Candida spp. infections, scedosporiosis and fusariosis. In large randomised trials, voriconazole was an effective and generally well tolerated primary treatment for candidiasis and invasive aspergillosis in adults and adolescents. More limited data also support the use of voriconazole for the treatment of invasive fungal infections in children, in those with rare fungal infections, such as Fusarium spp. or Scedosporium spp., and in those refractory to or intolerant of other standard antifungal therapies. The availability of both parenteral and oral formulations and the almost complete absorption of the drug after oral administration provide for ease of use and potential cost savings, and ensure that therapeutic plasma concentrations are maintained when switching from intravenous to oral therapy. On the other hand, the numerous drug interactions associated with voriconazole may limit its usefulness in some patients. Further clinical experience will help to more fully determine the position of voriconazole in relation to other licensed antifungal agents. In the meantime, voriconazole is a valuable emerging option for the treatment of invasive aspergillosis and rare fungal infections, including Fusarium spp. and Scedosporium spp. infections, and provides an alternative option for the treatment of candidiasis, particularly where the causative organism is inherently resistant to other licensed antifungal agents.

Caspofungin for the treatment of fungal infections: a systematic review of randomized controlled trials

During the last decade, owing to the low effectiveness and high toxicity of older antifungals, new antifungal agents have been released to the market for the treatment of patients with fungal infections. Several randomized controlled trials (RCTs) have been designed to evaluate the effectiveness of caspofungin in comparison with other antifungal agents. This review was conducted to examine further the role of caspofungin in the treatment of patients with fungal, mainly Candida, infections. Two reviewers independently performed the literature search, study selection and data extraction from relevant RCTs. A total of six RCTs comparing caspofungin with amphotericin B (deoxycholate in four and liposomal in one RCT) or fluconazole (in one RCT), which studied a total of 1974 patients, were included in our review. Success of the applied treatment in the clinically evaluable patients was achieved in 496/943 (52.6%) of the caspofungin-treated patients and in 381/852 (44.7%) of the amphotericin B- and lipid amphotericin B-treated patients. Discontinuation due to drug toxicity was significantly less common in patients receiving caspofungin than amphotericin B (odds ratio (OR) 0.25, 95% confidence interval (CI) 0.07-0.85, random effects model). Development of nephrotoxicity, hypokalaemia and fever also occurred significantly less often with caspofungin than amphotericin B (OR 0.23, 95% CI 0.14-0.36, fixed effects model; OR 0.3, 95% CI 0.12-0.76, random effects model; and OR 0.26, 95% CI 0.08-0.79, random effects model, respectively). No difference in mortality was noted. Caspofungin was associated with better clinical outcomes (higher cure and fewer adverse effects) than amphotericin B in the treatment of patients with fungal infections.

Treatment of bilateral candidal endophthalmitis with intravenous caspofungin

PURPOSE

Fungal resistances to drugs are increasing. Caspofungin is a new antifungal agent effective in the treatment of invasive candidiasis. We report a case of candidal endophthalmitis that responded adequately to caspofungin.

METHODS

A 24-year-old man with acute myeloid leukemia presented with vision loss in both eyes. Visual acuity was 20/50 in the right eye and counting fingers in the left eye. Fundus examination revealed multiple, premacular, vitreous, pearl stringshaped condensations in the right eye and a subretinal abscess in the left eye. Treatment with 50 mg of intravenous caspofungin once daily was started.

RESULTS

After 1 month, inflammation in both eyes had decreased, although the left eye developed macular scarring. Medication at discharge was intravenous caspofungin once daily for another 6 weeks. Nine months after presentation, the patient had residual vitreous condensations in the premacular region of the right eye with visual acuity of 20/25 and severe macular scarring in the left eye with visual acuity of 20/100.

CONCLUSION

This case adds support for the use of caspofungin as monotherapy for candidal endophthalmitis. Further studies are necessary to determine treatment options for the new antifungal agents.

Variable Number of Tandem Repeats of TNF Receptor Type 2 Promoter as Genetic Biomarker of Susceptibility to Develop Invasive Pulmonary Aspergillosis

Tumor necrosis factor alpha (TNF-alpha) and lymphotoxin alpha (LT-alpha) are pivotal mediators of inflammatory responses in fungal infection diseases. We hypothesized that polymorphisms in genes of these cytokines or their receptors might increase the susceptibility of hematologic patients to develop invasive pulmonary aspergillosis (IPA). One hundred two hematologic patients and 124 age-matched controls were enrolled in the study, and the following standard single nucleotide polymorphisms were investigated: TNF-alpha -308 and +489, LT-alpha +252 and Tumor Necrosis Factor Receptor 2 (TNFR2) +676. Variable number of tandem repeats (VNTRs) at position -322 of the TNFR2 gene were also studied. Genotypic and allelic frequencies were similar between patients and controls. IPA was diagnosed in 54 of the 102 patients according to consensus criteria published by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group. TNF-alpha and LT-alpha polymorphisms were not associated with presence of IPA. Susceptibility to IPA was strongly associated with VNTR at position -322 in the promoter region of the TNR2 gene (p = 0.029) but was not associated with the presence of TNFR2 +676 polymorphism. A genetic difference in TNFR2 promoter VNTR may play a major role in susceptibility to IPA infection.

Treatment of Invasive Aspergillosis with Posaconazole in Patients Who Are Refractory to or Intolerant of Conventional Therapy: An Externally Controlled Trial

BACKGROUND

Invasive aspergillosis is an important cause of morbidity and mortality in immunocompromised patients. Current treatments provide limited benefit. Posaconazole is an extended-spectrum triazole with in vitro and in vivo activity against Aspergillus species.

METHODS

We investigated the efficacy and safety of posaconazole oral suspension (800 mg/day in divided doses) as monotherapy in an open-label, multicenter study in patients with invasive aspergillosis and other mycoses who were refractory to or intolerant of conventional antifungal therapy. Data from external control cases were collected retrospectively to provide a comparative reference group.

RESULTS

Cases of aspergillosis deemed evaluable by a blinded data review committee included 107 posaconazole recipients and 86 control subjects (modified intent-to-treat population). The populations were similar and balanced with regard to prespecified demographic and disease variables. The overall success rate (i.e., the data review committee-assessed global response at the end of treatment) was 42% for posaconazole recipients and 26% for control subjects (odds ratio, 4.06; 95% confidence interval, 1.50-11.04; P=.006). The differences in response between the modified intent-to-treat treatment groups were preserved across additional, prespecified subsets, including infection site (pulmonary or disseminated), hematological malignancy, hematopoietic stem cell transplantation, baseline neutropenia, and reason for enrollment (patient was refractory to or intolerant of previous antifungal therapy). An exposure-response relationship was suggested by pharmacokinetic analyses.

CONCLUSIONS

Although the study predates extensive use of echinocandins and voriconazole, these findings demonstrate that posaconazole is an alternative to salvage therapy for patients with invasive aspergillosis who are refractory to or intolerant of previous antifungal therapy.

Safety of long-term oral posaconazole use in the treatment of refractory invasive fungal infections

BACKGROUND

Invasive fungal infections are found most frequently in immunosuppressed and critically ill hospitalized patients. Antifungal therapy is often required for long periods. Safety data from the clinical development program of the triazole antifungal agent, posaconazole, were analyzed.

METHODS

A total of 428 patients with refractory invasive fungal infections (n = 362) or febrile neutropenia (n = 66) received posaconazole in 2 phase II/III open-label clinical trials. Also, 109 of these patients received posaconazole therapy for > or = 6 months. Incidences of treatment-emergent, treatment-related, and serious adverse events and abnormal laboratory parameters were recorded during these studies.

RESULTS

Treatment-emergent, treatment-related adverse events were reported in 38% of the overall patient population. The most common treatment-related adverse events were nausea (8%) and vomiting (6%). Treatment-related serious adverse events occurred in 8% of patients. Low rates of treatment-related corrected QT interval and/or QT interval prolongation (1%) and elevation of hepatic enzymes (2%) were reported as adverse events. Treatment-emergent, treatment-related adverse events occurred at similar rates in patients who received posaconazole therapy for < 6 months and > or = 6 months.

CONCLUSIONS

Prolonged posaconazole treatment was associated with a generally favorable safety profile in seriously ill patients with refractory invasive fungal infections. Long-term therapy did not increase the risk of any individual adverse event, and no unique adverse event was observed with longer exposure to posaconazole.

Concomitant tacrolimus and micafungin pharmacokinetics in healthy volunteers

Tacrolimus is an approved immunosuppressive agent and a known substrate for CYP3A. Micafungin is an echinocandin antifungal agent and a mild inhibitor of CYP3A metabolism in vitro. The objectives of this study were to evaluate the pharmacokinetics of tacrolimus (5 mg oral) and micafungin (100 mg intravenous) alone and with concomitant administration (n=26). Tacrolimus area under the concentration-time curve was 298+/-135 microg*h/L when tacrolimus was administered alone, 305+/-129 microg*h/L (P=.8; confidence interval 89%, 118%) when tacrolimus was given with single-dose micafungin, and 282+/-138 microg*h/L (P=.4; confidence interval 82%, 107%) when tacrolimus was given with steady-state micafungin. Despite the mild inhibition of CYP3A in vitro by micafungin, there does not appear to be a drug interaction with tacrolimus and micafungin either with single-dose or steady-state micafungin administration.

Caspofungin: a review of its use in the treatment of fungal infections

Caspofungin (Cancidas) is the first of a new class of antifungal agents, the echinocandins, that inhibit the synthesis of the fungal cell wall component beta-(1,3)-D-glucan. Caspofungin is administered once daily by slow intravenous infusion and is used to treat infections caused by Candida spp. and Aspergillus spp. Caspofungin is a valuable new antifungal agent with a novel mechanism of action. In comparative clinical trials, caspofungin was no less effective than liposomal amphotericin B in the empirical treatment of neutropenic patients with persistent fever, amphotericin B deoxycholate in the treatment of invasive candidiasis or fluconazole in the treatment of oesophageal candidiasis. Caspofungin also displayed broadly similar efficacy to amphotericin B deoxycholate in oesophageal or oropharyngeal candidiasis and was effective as salvage therapy in patients with invasive aspergillosis who were refractory to or intolerant of standard therapy. The tolerability profile of caspofungin was similar to that of fluconazole and superior to that of amphotericin B deoxycholate and liposomal amphotericin B. Therefore, in the appropriate indications, caspofungin is a viable alternative to amphotericin B deoxycholate, liposomal amphotericin B or fluconazole.

Voriconazole in the treatment of fungal osteomyelitis of the orbit in the immunocompromised host

Scedosporium apiospermum is an uncommon cause of fungal infection in the orbit and sinus. Morbidity and mortality rates in immunocompromised patients are high. We review the first case of Scedosporium apiospermum orbito-sinus infection that was successfully treated with the new antifungal agent voriconazole. We highlight the efficacy of this drug, particularly in the treatment of osteomyelitis of the orbit and sinus, which may lead to an improvement in survival rates after Scedosporium infection.

Successful treatment of aspergillus brain abscess in a child with acute lymphoblastic leukemia and liver failure

Invasive fungal infection continues to pose a significant threat to immunocompromised patients, with cerebral aspergillosis being among the most feared ones. The authors describe an adolescent girl with acute lymphoblastic leukemia (ALL) with subsequent acute liver failure, who developed an aspergillus brain abscess. The patient was treated with combined antifungal therapy using amphotericin B local instillation, prolonged systemic amphotericin B colloidal dispersion along with vinca alkaloids-containing chemotherapy, followed by neurosurgical débridement and oral voriconazole in the setting of ongoing antileukemic maintenance chemotherapy. Her ALL remains now in complete remission 30 months from diagnosis, with no evidence of fungal infection.

Aspergillus mastoiditis in a patient with systemic lupus erythematosus: a case report

Fungal mastoiditis caused by Aspergillus fumigatus predominantly occurs in immunocompromised patients. Invasive temporal bone mycoses are rare. They are usually associated with host immunodeficiency, are difficult to diagnose, and many cases are fatal. Treatment consists of antifungal chemotherapy, surgical debridement, and attempts to control the underlying immunological condition. Published reports describe patients with previous ear pathology and associated facial nerve dysfunction. We report a case in a patient with systemic lupus erythematosus. A good outcome followed surgical debridement and the use of a new triazole antifungal agent, voriconazole. Our patient's facial nerve function was unaffected. The presence of normal facial nerve function, however, does not exclude the possibility of invasive fungal mastoiditis.

Caspofungin as first line therapy of pulmonary invasive fungal infections in 32 immunocompromised patients with hematologic malignancies

Invasive Fungal Infections (IFI) remain a severe and major complication among patients with hematologic diseases, but the recent availability of new antifungal agents (echinocandins and new azoles) have improved the chance of cure. Caspofungin (Cancidas-Merck) is a large lipopeptide molecule able to inhibit the enzyme complex 1,3-d-glucan synthetase; this action specifically damages the fungal cell wall. Caspofungin (CAS) is active, in vitro and in vivo, against most Candida species and Aspergillus species. We report on our experience with this drug as first-line therapy for proven or probable pulmonary IFI in immunocompromised patients with hematologic malignancies. Thirty-two consecutive patients (20 males and 12 females, with a median age of 52 yr) have been treated with CAS (27 acute leukemias, 1 chronic leukemia, 3 lymphomas and 1 multiple myeloma). Sixteen patients (50%) had a relapsed or resistant hematologic disease, while 12 patients were in complete remission and 4 were at onset of disease; 8/32 (25%) developed IFI after a hematopoietic stem cell transplant (HSCT) procedure. Seven out of 32 patients (22%) had a proven pulmonary IFI (7/7 Aspergillosis) and 25 (78%) had a probable IFI with pulmonary localization as defined according to international consensus. Thirty-one patients (97%) had less than 1000 granulocytes/mL at onset of infection and at the start of CAS therapy. The CAS was given at the dose of 70 mg on day 1, followed by 50 mg/day. Median duration of CAS therapy was 20 d (range 8-64); all the 31 neutropenic patients received concomitant granulocyte colony-stimulating factor (G-CSF). The overall response rate was 56% (18/32) with 12/18 complete responses and 6/18 partial responses; two patients (6%) had a stable disease. Twelve out of 32 (38%) did not respond and seven died of mycotic infection. Univariate analysis showed that granulocytes recovery (>500/mL vs. <500/mL) and status of hematologic disease (remission/onset vs. refractory/relapsed) were significantly associated to favourable outcome. No clinical adverse events (AE) were reported and only a grades I and II transient increase of serum alkaline phosphatase and/or transaminases occurred in 4/32 (12%) patients. After CAS therapy six non-responders and six cases with a partial or stable response were rescued with voriconazole. Two out of six patients (33%) in the former group and 6/6 (100%) in the latter obtained a complete resolution of IFI. Our experience suggests an efficacy of CAS, in combination with G-CSF, as first-line treatment of proven or probable IFI with pulmonary localization. The drug was well tolerated and there were no significant hepatic AE even in patients receiving CAS with cyclosporine after a HSCT. A significant proportion of non-responders or partial responders to CAS can be rescued with a subsequent voriconazole-based therapy.

Pseudoporphyria induced by voriconazole

Pseudoporphyria is an uncommon blistering disorder with clinical and histologic similarities to porphyria cutanea tarda but which lacks urine and serum porphyrin elevations. Pseudoporphyria has been linked with numerous causes including chronic renal failure, ultraviolet radiation, and numerous medications. We report a case of pseudoporphyria attributed to the relatively new triazole antifungal agent voriconazole. This medication has not been previously identified as a cause of pseudoporphyria.

Invasive Candida species infections: a 5 year population-based assessment

OBJECTIVES

Candida species have emerged as important causes of invasive infections and rates of resistance to standard antifungal therapies are rising. The objective of this study was to define the occurrence of, risk factors for, and antifungal susceptibilities of invasive Candida species infections in a large Canadian health region.

METHODS

Population-based surveillance was conducted for invasive Candida species infections in the Calgary Health Region during a 5 year period and susceptibility testing was performed.

RESULTS

The annual incidence of invasive Candida species infection was 2.9 per 100,000 population (0.2 and 2.8 per 100,000 for central nervous system and bloodstream infection, respectively). The very young and elderly were at highest risk for invasive Candida species infections. Several risk factors for developing invasive Candida species infection were identified with chronic haemodialysis, organ transplant recipient, and cancer patients at highest risk. Thirty percent (56/184; 43 susceptible, dose-dependent and 13 resistant) of isolates demonstrated reduced susceptibility to fluconazole. Only one (1%) isolate had reduced susceptibility to amphotericin B and six (3%) and three (2%) isolates had minimum inhibitory concentrations of >or=1 mg/L to voriconazole and caspofungin, respectively. Overall, 40% of patients died in-hospital for an annual mortality rate of 1.2 per 100,000.

CONCLUSIONS

Candida species are an important cause of invasive infection and patients with co-morbidities and extremes of age are at highest risk. Alternatives to fluconazole should be considered for initial empiric therapy in patients with severe invasive Candida species infections.

Activity of aminocandin (IP960) compared with amphotericin B and fluconazole in a neutropenic murine model of disseminated infection caused by a fluconazole-resistant strain of Candida tropicalis

OBJECTIVES

To compare the activity of aminocandin (IP960), a new echinocandin with broad-spectrum in vitro activity against Aspergillus and Candida spp., with that of amphotericin B and fluconazole in a temporarily immunocompromised murine model of disseminated candidiasis.

METHODS

Mice were rendered neutropenic with cyclophosphamide and infected intravenously 3 days later with a fluconazole-resistant Candida tropicalis strain. Mice were treated with intraperitoneal amphotericin B (5 mg/kg/dose), oral fluconazole (50 mg/kg/dose), intravenous aminocandin (0.1--5 mg/kg/dose) or solvent control for 9 days. Mice were observed for survival and survivors were sacrificed 11 days post-infection. Kidneys, liver, brain and lungs were removed for semi-quantitative culture.

RESULTS

Control mice had 90--100% mortality. After infection with C. tropicalis, aminocandin 2.5 and 5 mg/kg/day and amphotericin B yielded 80% survival; aminocandin 1 mg/kg/day yielded 70% survival; aminocandin 0.25 and 0.1 mg/kg/day yielded 30% and 20% survival, respectively; and fluconazole 50 mg/kg/day and control regimens yielded 10% and 0--10% survival, respectively. Aminocandin 2.5 and 5.0 mg/kg/day and amphotericin B were superior in reducing mortality compared with aminocandin 0.25 and 0.1 mg/kg/day, fluconazole and controls (P<0.047). The only regimen to reduce organ burdens below detectable levels was amphotericin B, which cleared 40% of mice. All organ burdens in the aminocandin 1.0, 2.5 and 5.0 mg/kg/day and amphotericin B regimens were significantly lower than other groups (P<0.02).

CONCLUSIONS

The data demonstrate that aminocandin at doses of >or=1.0 mg/kg/day is as effective as amphotericin B at improving survival and reducing organ burdens in this murine model of disseminated C. tropicalis.

Breakthrough Candida infections in patients receiving voriconazole

OBJECTIVE

To describe 2 instances of breakthrough Candida infection in 2 patients on treatment doses of voriconazole.

CASE SUMMARIES

A 27-year-old woman with systemic lupus erythematosus was receiving high-dose voriconazole (400 mg twice daily) for central nervous system lesions of unknown origin and developed oral thrush. The patient was receiving concomitant therapy with phenytoin 400 mg/day. The voriconazole dose was increased to 400 mg 3 times daily, and the thrush resolved. A 50-year-old man with HIV infection was receiving enfuvirtide, lamivudine, tenofovir, and efavirenz 600 mg/day, as well as prophylactic trimethoprim/sulfamethoxazole and azithromycin. He was started on voriconazole 200 mg twice daily for pulmonary aspergillosis and developed esophageal candidiasis. The voriconazole dose was increased to 350 mg twice daily, and the thrush eventually resolved.

DISCUSSION

Both reactions were probable according to the Naranjo probability scale. Significant drug interactions may have played a role in the development of breakthrough infections in these patients, specifically with phenytoin and efavirenz. Voriconazole is metabolized primarily by CYP2C19, as well as CYP2C9 and CYP3A4. Voriconazole is also known to inhibit these enzymes, and the manufacturer reports an extensive list of drugs that interact with voriconazole.

CONCLUSIONS

Although requiring systematic evaluation, there may be a role for voriconazole serum concentration monitoring to ensure therapeutic efficacy when significant drug interactions are suspected.

Drug dosing in chronic kidney disease

Patients with chronic kidney disease (CKD) are at high risk for adverse drug reactions and drug-drug interactions. Drug dosing in these patients often proves to be a difficult task. Renal dysfunction-induced changes in human pathophysiology regularly results may alter medication pharmacodynamics and handling. Several pharmacokinetic parameters are adversely affected by CKD, secondary to a reduced oral absorption and glomerular filtration; altered tubular secretion; and reabsorption and changes in intestinal, hepatic, and renal metabolism. In general, drug dosing can be accomplished by multiple methods; however, the most common recommendations are often to reduce the dose or expand the dosing interval, or use both methods simultaneously. Some medications need to be avoided all together in CKD either because of lack of efficacy or increased risk of toxicity. Nevertheless, specific recommendations are available for dosing of certain medications and are an important resource, because most are based on clinical or pharmacokinetic trials.

Photoaging and phototoxicity from long-term voriconazole treatment in a 15-year-old girl

Voriconazole is a second-generation triazole that was approved by the Food and Drug Administration in May 2002 for treatment of severe fungal infections. In clinical trials it demonstrated superior efficacy in addition to a survival benefit when compared with the then current treatment standard, amphotericin B, for primary treatment of invasive aspergillosis. Voriconazole is a highly selective inhibitor of fungal cytochrome P450 enzymes. Adverse cutaneous reactions have been reported, namely cheilitis, erythema, discoid lupus erythematosus, Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, and photosensitivity reactions. We report a case of photoaging caused by voriconazole therapy. A 15-year-old patient developed cheilitis and erythema over the sun-exposed areas of her body 5 weeks after beginning voriconazole for a severe fungal infection. The lesions showed a mild transient improvement before subsequent photodamage occurred to the back of her forearms, back of her hands, and face. Voriconazole was discontinued once the fungal infection had completely resolved. The patient's blisters, erythema, and cheilitis resolved after discontinuation of voriconazole. However, she was left with solar elastotic changes, multiple lentigines, and ephelides of sun-exposed areas. These cutaneous manifestations may represent a unique adverse event caused by a new second-generation triazole.

Sepsis associated with immunosuppressive medications: an evidence-based review

OBJECTIVE

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for sepsis associated with immunosuppressive medications that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis.

DESIGN

The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee.

METHODS

The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591.

CONCLUSION

Immunosuppressed patients, by definition, are susceptible to a wider spectrum of infectious agents than immunologically normal patients and, thus, require a broader spectrum antimicrobial regimen when they present with sepsis or septic shock. Special expertise managing immunosuppressed patient populations is needed to predict and establish the correct diagnosis and to choose appropriate empiric and specific agents and maximize the likelihood that patients will survive these microbial challenges.

Safety and Potential of Drug Interactions of Caspofungin and Voriconazole in Multimorbid Patients

Due to their broad antimycotic spectrum and the relatively low rate of side effects, the two antifungals caspofungin and voriconazole are considered as attractive therapeutic alternatives to amphotericin B. However, treatment of severe mycotic infections in patients taking co-medication is associated with the risk of severe adverse drug interactions. The risk of such interactions is increased if voriconazole and, much less pronounced caspofungin, are co-administered with drugs which have an inducing or inhibiting effect on the CYP 450 system, primarily on the isoenzymes CYP2C19, CYP2C9 and CYP3A4. This review provides a comprehensive overview on the potential drug interactions of caspofungin and voriconazole in multimorbid patients.