Population Pharmacokinetic Model and Optimal Sampling Strategies for Micafungin in Critically Ill Patients Diagnosed with Invasive Candidiasis.

Candida bloodstream infections are associated with high attributable mortality, where early initiation of adequate antifungal therapy is important to increase survival in critically ill patients. The exposure variability of micafungin, a first-line agent used for the treatment of invasive candidiasis, in critically ill patients is significant, potentially resulting in underexposure in a substantial portion of these patients. The objective of this study was to develop a population pharmacokinetic model including appropriate sampling strategies for assessing micafungin drug exposure in critically ill patients to support adequate area under the concentration-time curve (AUC) determination. A two-compartment pharmacokinetic model was developed using data from intensive care unit (ICU) patients (n = 19), with the following parameters: total body clearance (CL), volume of distribution of the central compartment (V1), inter-compartmental clearance (CL12), and volume of distribution of the peripheral compartment (V2). The final model was evaluated with bootstrap analysis and the goodness-of-fit plots for the population and individual predicted micafungin plasma concentrations. Optimal sampling strategies (with sampling every hour, 24 h per day) were developed with 1- and 2-point sampling schemes. Final model parameters (±SD) were: CL = 1.03 (0.37) (L/h/1.85 m2), V1 = 0.17 (0.07) (L/kg LBMc), CL12 = 1.80 (4.07) (L/h/1.85 m2), and V2 = 0.12 (0.06) (L/kg LBMc). Sampling strategies with acceptable accuracy and precision were developed to determine the micafungin AUC. The developed model with optimal sampling procedures provides the opportunity to achieve quick optimization of the micafungin exposure from a single blood sample using Bayesian software and may be helpful in guiding early dose decision-making.

Graded response model fit, measurement invariance and (comparative) precision of the Dutch-Flemish PROMIS® Upper Extremity V2.0 item bank in patients with upper extremity disorders.

BACKGROUND: The Dutch-Flemish PROMIS® Upper Extremity (DF-PROMIS-UE) V2.0 item bank was recently developed using Item Response Theory (IRT). Unknown for this bank are: (1) if it is legitimate to calculate IRT-based scores for short forms and Computerized Adaptive Tests (CATs), which requires that the items meet the assumptions of and fit the IRT-model (Graded Response Model [GRM]);(2) if it is legitimate to compare (sub) groups of patients using this measure, which requires measurement invariance; and (3) the precision of the estimated patients' scores for patients with different levels of functioning and compared to legacy measures. Aims were to evaluate (1) the assumptions of and fit to the GRM, (2) measurement invariance and (3) (comparative) precision of the DF-PROMIS-UE v2.0. METHODS: Cross-sectional data were collected in Dutch patients with upper extremity disorders. Assessed were IRT-assumptions (unidimensionality [bi-factor analysis], local independence [residual correlations], monotonicity [coefficient H]), GRM item fit, measurement invariance (absence of Differential Item Functioning [DIF] due to age, gender, center, duration, and location of complaints) and precision (standard error of IRT-based scores across levels of functioning). To study measurement invariance for language [Dutch vs. English], additional US data were used. Legacy instruments were the Disability of the Arm, Shoulder and Hand (DASH), the QuickDASH and the Michigan Hand Questionnaire (MHQ). RESULTS: In total 521 Dutch (mean age ± SD = 51 ± 17 years, 49% female) and 246 US patients (mean age ± SD = 48 ± 14 years, 69% female) participated. The DF-PROMIS-UE v2.0 item bank was sufficiently unidimensional (Omega-H = 0.80, Explained Common Variance = 0.68), had negligible local dependence (four out of 1035 correlations > 0.20), good monotonicity (H = 0.63), good GRM fit (no misfitting items) and demonstrated sufficient measurement invariance. Precise estimates (Standard Error < 3.2) were obtained for most patients (7-item short form, 88.5%; standard CAT, 91.3%; and, fixed 7-item CAT, 87.6%). The DASH displayed better reliability than the DF-PROMIS-UE short form and standard CAT, the QuickDASH displayed comparable reliability. The MHQ-ADL displayed better reliability than the DF-PROMIS-UE short form and standard CAT for T-scores between 28 and 50. For patients with low function, the DF-PROMIS-UE measures performed better. CONCLUSIONS: The DF-PROMIS-UE v2.0 item bank showed sufficient psychometric properties in Dutch patients with UE disorders.

Pharmacokinetic Properties of Micafungin in Critically Ill Patients Diagnosed with Invasive Candidiasis.

The estimated attributable mortality rate for invasive candidiasis (IC) in the intensive care unit (ICU) setting varies from 30 to 40%. Physiological changes in critically ill patients may affect the distribution and elimination of micafungin, and therefore, dosing adjustments might be mandatory. The objective of this study was to determine the pharmacokinetic parameters of micafungin in critically ill patients and assess the probability of target attainment. Micafungin plasma concentrations were measured to estimate the pharmacokinetic properties of micafungin. MIC values for Candida isolates were determined to assess the probability of target attainment for patients. Data from 19 patients with suspected or proven invasive candidiasis were available for analysis. The median area under the concentration-time curve from 0 to 24 h at steady state (AUC0-24) was 89.6 mg · h/liter (interquartile range [IQR], 75.4 to 113.6 mg · h/liter); this was significantly lower than the median micafungin AUC0-24 values of 152.0 mg · h/liter (IQR, 136.0 to 162.0 mg · h/liter) and 134.0 mg · h/liter (IQR, 118.0 to 148.6 mg · h/liter) in healthy volunteers (P = <0.0001 and P = <0.001, respectively). All Candida isolates were susceptible to micafungin, with a median MIC of 0.016 mg/liter (IQR, 0.012 to 0.023 mg/liter). The median AUC0-24/MIC ratio was 5,684 (IQR, 4,325 to 7,578), and 3 of the 17 evaluable patients (17.6%) diagnosed with proven invasive candidiasis did not meet the AUC/MIC ratio target of 5,000. Micafungin exposure was lower in critically ill patients than in healthy volunteers. The variability in micafungin exposure in this ICU population could be explained by the patients' body weight. Our findings suggest that healthier patients (sequential organ failure assessment [SOFA] score of <10) weighing more than 100 kg and receiving 100 mg micafungin daily are at risk for inappropriate micafungin exposure and potentially inadequate antifungal treatment. (This study has been registered at ClinicalTrials.gov under identifier NCT01716988.).

Are illness perception and coping style associated with the delay between symptom onset and the first general practitioner consultation in early rheumatoid arthritis management? An exploratory study within the CareRA trial.

OBJECTIVES: Persons who are later diagnosed with early rheumatoid arthritis (ERA) often delay their first contact with a health professional after symptom onset. Besides initial symptoms, psychosocial characteristics of individuals may influence their help-seeking behaviour. We explored the role of disease characteristics, illness perception, and coping in patient-related delay before treatment initiation in recently diagnosed patients with ERA. METHOD: This exploratory, cross-sectional study included 112 patients with ERA from the Care for early RA (CareRA) trial for whom complete data on patient-related delay, coping, and illness perception were available. In addition to baseline sociodemographic and clinical data, the patients' psychosocial profiles were assessed with the Utrecht Coping List (UCL) and the revised Illness Perception Questionnaire (IPQ-R). Correlations were measured by Spearman's rho. Using regression analyses, we weighted the association of variables with patient-related delay. RESULTS: Patient-related delay was positively correlated with perceptions of causality including psychological attributions (r = 0.301, p = 0.001), risk factors (r = 0.189, p = 0.045), immunity (r = 0.261, p = 0.005), and passive coping (r = 0.222, p = 0.018). It was negatively correlated with the 28 swollen joint count (SJC28; r = -0.194, p = 0.040), perceptions of treatment control (r = -0.271, p = 0.004), and illness coherence (r = -0.208, p = 0.028). Clinical and psychosocial variables explained 15% and 18%, respectively, of the variability in patient-related delay. CONCLUSIONS: Aside from a lower SJC, a longer patient-related delay was correlated with a passive coping style, a strong conviction of symptom causality, poor expected treatment control, and a feeling of limited illness coherence. Psychosocial aspects influence individuals' help-seeking behaviour and are worth considering when aiming for a reduction in ERA treatment delay.

Methotrexate in combination with other DMARDs is not superior to methotrexate alone for remission induction with moderate-to-high-dose glucocorticoid bridging in early rheumatoid arthritis after 16†weeks of treatment: the CareRA trial.

OBJECTIVES: To compare the efficacy and safety of intensive combination strategies with glucocorticoids (GCs) in the first 16 weeks (W) of early rheumatoid arthritis (eRA) treatment, focusing on high-risk patients, in the Care in early RA trial. METHODS: 400 disease-modifying antirheumatic drugs (DMARD)-naive patients with eRA were recruited and stratified into high risk or low risk according to classical prognostic markers. High-risk patients (n=290) were randomised to 1/3 treatment strategies: combination therapy for early rheumatoid arthritis (COBRA) Classic (methotrexate (MTX)+ sulfasalazine+60 mg prednisone tapered to 7.5 mg daily from W7), COBRA Slim (MTX+30 mg prednisone tapered to 5 mg from W6) and COBRA Avant-Garde (MTX+leflunomide+30 mg prednisone tapered to 5 mg from W6). Treatment modifications to target low-disease activity were mandatory from W8, if desirable and feasible according to the rheumatologist. The primary outcome was remission (28 joint disease activity score calculated with C-reactive protein <2.6) at W16 (intention-to-treat analysis). Secondary endpoints were good European League Against Rheumatism response, clinically meaningful health assessment questionnaire (HAQ) response and HAQ equal to zero. Adverse events (AEs) were registered. RESULTS: Data from 98 Classic, 98 Slim and 94 Avant-Garde patients were analysed. At W16, remission was reached in 70.4% Classic, 73.6% Slim and 68.1% Avant-Garde patients (p=0.713). Likewise, no significant differences were shown in other secondary endpoints. However, therapy-related AEs were reported in 61.2% of Classic, in 46.9% of Slim and in 69.1% of Avant-Garde patients (p=0.006). CONCLUSIONS: For high-risk eRA, MTX associated with a moderate step-down dose of GCs was as effective in inducing remission at W16 as DMARD combination therapies with moderate or high step-down GC doses and it showed a more favourable short-term safety profile. EUDRACT NUMBER: 2008-007225-39.

A detailed analysis of treatment delay from the onset of symptoms in early rheumatoid arthritis patients.

OBJECTIVES: A treatment delay of more than 12 weeks can negatively affect treatment response in rheumatoid arthritis (RA). Our aim was to quantify the different stages of delay before RA treatment in different rheumatology centres and to explore influencing factors. METHOD: A total of 156 disease-modifying anti-rheumatic drug (DMARD)-naive early RA patients were included from eight practices: one academic hospital, five general hospitals, and two private practices. Eight different types of delay were defined from symptom onset until treatment initiation. Information on the duration of each stage of delay was collected from the patient, their general practitioner (GP), and patient files at the rheumatology practice. Patient/GP demographics and disease activity/severity parameters were recorded. RESULTS: The median total delay from symptom onset until treatment initiation was 23 weeks whereas patient-, GP- and rheumatologist-related median delay was 10, 4, and 7 weeks, respectively. Only 21.6% of the patients had a total delay of less than 12 weeks. The total median delay in private rheumatology practices was less than in academic and general hospitals (p < 0.001). Furthermore, RA patients treated within 12 weeks of symptom onset showed a higher level of disease activity. The duration of rheumatologist-related delay was inversely correlated with disease activity parameters. Patients with morning stiffness were treated, on average, 3 weeks sooner than those without morning stiffness (p < 0.006). CONCLUSIONS: In only one out of five early RA patients was treatment initiated within 12 weeks of symptom onset, as recommended. Patient-related delay contributed most to overall delay. Disease activity and type of rheumatology centre are pivotal determinants of delay.

Factors influencing the prescription of intensive combination treatment strategies for early rheumatoid arthritis.

OBJECTIVES: Despite the availability and demonstrated effectiveness of intensive combination treatment strategies (ICTS) for early rheumatoid arthritis (RA), a discrepancy seems to exist between theoretical evidence and actual prescription in daily practice. The purpose of this study was to explore and identify the factors influencing the prescription of ICTS. METHOD: This study involved rheumatologists and nurses participating in the Care for Rheumatoid Arthritis (CareRA) trial, a multicentre randomized controlled trial (RCT) comparing different ICTS for early RA with conventional disease-modifying anti-rheumatic drugs (DMARDs) plus step-down glucocorticoids (GCs). A qualitative study was carried out using individual semi-structured interviews. Each interview was recorded, transcribed literally, and analysed thematically. In addition, observations at outpatient clinics were used to clarify the interpretation of the results. RESULTS: We interviewed 26 rheumatologists and six nurses and observed five outpatient visits. Identified facilitators included available scientific evidence, personal faith in treatment strategy, staff support, and low treatment costs. Rheumatologists had no doubts about the value of methotrexate (MTX) but some questioned the value of combination strategy, others the effectiveness and/or the dosage of individual compounds. Additional barriers for prescribing ICTS included need for patient education, fear for patients' preconceptions, concerns about applicability to the individual patient, difficulties with breaking routine, interference with organizational structures and processes, time constraints, and lack of financial support. CONCLUSIONS: A heterogeneous set of factors highlights the complexity of prescribing ICTS for early RA in daily clinical practice. Future improvement strategies should stimulate the facilitators while at the same time addressing the barriers. The generalizability of these findings to other health care systems needs further examination.

Busulfan Exposure Target Attainment in Adults Undergoing Allogeneic Hematopoietic Cell Transplantation: A Single Day Versus a Multiple Day Therapeutic Drug Monitoring Regimen.

Busulfan exposure has previously been linked to clinical outcomes, hence the need for therapeutic drug monitoring (TDM). Study objective was to evaluate the effect of day 1 TDM-guided dosing (regimen d1) versus days 1 + 2 TDM-guided dosing (regimen d1 + 2) on attaining adequate busulfan exposure. In this observational study, we included all adults who received an allogeneic HCT with intravenous once daily busulfan over 4 days as part of the conditioning regimen at the University Medical Centre Utrecht or between July 31, 2014 and November 12, 2021. The primary outcome was attainment of the therapeutic busulfan target (cumulative area under the curve [AUCcum] 80-100 mg*h/L). Dose adjustment was based on the estimated AUC of the preceding dosing day(s). Additional TDM was performed in the event of large dose adjustments (≥25%). The choice of TDM regimen was solely based on the first day the busulfan dose was administered (regimen d1 + 2 occurred when conditioning started on a Saturday). In all patients, blood sampling was performed on day 4 for evaluation. The AUCcum was estimated using a validated population pharmacokinetic model. Busulfan target exposure was compared between both TDM regimen groups using a propensity score adjusted logistic regression model. The variance in the AUCcum between the TDM regimens was compared using the F-test. Patients were stratified for age (categorical). In regimen d1, 87.6% (n = 113/129) attained a therapeutic busulfan exposure, while in regimen d1 + 2 a proportion of 97.4% was found (n = 74/76, adjusted odds ratio for non-therapeutic AUC = 0.19, 95% confidence interval [95% CI]: 0.04-0.89). Variance of busulfan exposure in the regimen d1 group (SD = 6.8 mg*h/L) differed significantly from the variance in the regimen d1 + 2 group (SD = 3.6 mg*h/L, F-test, P < .001). Performing busulfan TDM on both day 1 and day 2, rather than only on day 1, improves busulfan target exposure attainment in adults undergoing HCT, provided that subsequent TDM is carried out if required.

Busulfan target exposure attainment in children undergoing allogeneic hematopoietic cell transplantation: a single day versus a multiday therapeutic drug monitoring regimen.

Busulfan exposure has previously been linked to clinical outcomes, hence the need for therapeutic drug monitoring (TDM). Study objective was to evaluate the effect of day 1 TDM-guided dosing (regimen d1) versus days 1 + 2 TDM-guided dosing (regimen d1 + 2) on attaining adequate busulfan exposure. In this observational study, we included all children receiving busulfan-based allogeneic hematopoietic cell transplantation. Primary outcome was the percentage of patients achieving busulfan target attainment in both TDM regimens. Secondary outcomes were the variance in busulfan exposure and day-4 clearance (Clday4) estimates between both TDM regimens and dosing day 1 and 2. In regimen d1, 84.3% (n = 91/108) attained a therapeutic busulfan exposure, while in regimen d1 + 2 a proportion of 90.9% was found (n = 30/33, not-significant). Variance of Clday4 estimate based on busulfan day 2 concentrations was significantly smaller than the variance of Clday4 estimates based on day 1 concentrations (p < 0.001). Therefore, day 1-guided TDM (pharmacometric model-based) of busulfan may be sufficient for attaining optimal target exposure, provided that subsequent TDM is carried out if required. However, performing TDM on subsequent days may be beneficial, as measurements on day 2 seemed to reduce the variance in the estimated clearance as compared to day 1 sampling.

Plasma concentrations of caspofungin at two different dosage regimens in a patient with hepatic dysfunction.

The currently recommended dosage regimen of caspofungin (50 mg/day) was developed for patients with invasive candidiasis. With invasive aspergillosis, successful outcomes occur in less than half the patients. We evaluate the pharmacokinetics in a patient with elevated liver enzyme levels after liver transplantation, who received caspofungin for the treatment of aspergillosis. Plasma concentrations of caspofungin were monitored at 2 different dosage regimens. The area under the concentration-time curve (AUC) at a dosage of 70 mg was 191 mg h/L and was associated with an increase in liver enzymes. After dose reduction to 50 mg with an AUC of 100 mg h/L, liver enzymes normalized. In conclusion, caspofungin plasma concentrations may be helpful to evaluate exposure and reduce the need for off-label dosing.

Invasive Candidiasis in the Elderly: Considerations for Drug Therapy.

Candida infections in the elderly are an important and expanding clinical problem, with significantly higher mortality in this group than in younger patients. The increasing problem of invasive Candida infections may be related to higher prevalence of immunocompromised older people and the emergence of treatment resistance. Older people, especially the frail and critically ill, are at higher risk of medication-related harmful effects due to changes in pharmacokinetics and pharmacodynamics, which may be further complicated by organ dysfunction, diminished homeostatic control, co-morbidities and polypharmacy. Here, we review the available options for the treatment of Candida infections and provide insights into the challenges surrounding the optimal use of antifungal drugs in the elderly.

The performance of matrices in daily clinical practice to predict rapid radiologic progression in patients with early RA.

OBJECTIVE: To compare in daily clinical practice the reliability of matrices that forecast rapid radiologic progression (RRP) at year one, at year two, and over 2 years in patients with early rheumatoid arthritis (RA). METHODS: Overall, 74 early RA patients with X-rays of hands and feet at baseline, year one, and year two were included. Initial DMARD combination therapy with steroids (ICTS) or DMARD monotherapy (IMT) was initiated according to patients' RA severity, based on rheumatologist opinion. The images were scored via the modified Sharp/van der Heijde (SvH) method. A total Sharp score progression of equal or higher than five per year was considered RRP. Six matrices were tested: ASPIRE CRP/ESR matrices, the BEST matrix, two SWEFOT matrices, and the ESPOIR matrix. Patients were placed in each of them yielding a RRP probability. The performance was tested by Area Under the Curve analysis reflecting the predictive value. RESULTS: Four patients developed RRP in year one, five in year two, and four over 2 years. With regard to face validity, the predicted probability did not correspond to the risk in reality: the one ICTS patient who developed RRP over 2 years was always found in the lowest RRP categories of all matrices. The ASPIRE CRP matrix yielded at least a moderate predicting value for the three time points. The other matrices showed moderate to no predicting value. CONCLUSION: The performance of all matrices was disappointing and it is impossible to fully rely on the existing matrices in daily clinical practice.