How accurate and precise are limited sampling strategies in estimating exposure to mycophenolic acid in people with autoimmune disease?

Mycophenolic acid (MPA) is a potent immunosuppressant agent, which is increasingly being used in the treatment of patients with various autoimmune diseases. Dosing to achieve a specific target MPA area under the concentration-time curve from 0 to 12 h post-dose (AUC12) is likely to lead to better treatment outcomes in patients with autoimmune disease than a standard fixed-dose strategy. This review summarizes the available published data around concentration monitoring strategies for MPA in patients with autoimmune disease and examines the accuracy and precision of methods reported to date using limited concentration-time points to estimate MPA AUC12. A total of 13 studies were identified that assessed the correlation between single time points and MPA AUC12 and/or examined the predictive performance of limited sampling strategies in estimating MPA AUC12. The majority of studies investigated mycophenolate mofetil (MMF) rather than the enteric-coated mycophenolate sodium (EC-MPS) formulation of MPA. Correlations between MPA trough concentrations and MPA AUC12 estimated by full concentration-time profiling ranged from 0.13 to 0.94 across ten studies, with the highest associations (r (2) = 0.90-0.94) observed in lupus nephritis patients. Correlations were generally higher in autoimmune disease patients compared with renal allograft recipients and higher after MMF compared with EC-MPS intake. Four studies investigated use of a limited sampling strategy to predict MPA AUC12 determined by full concentration-time profiling. Three studies used a limited sampling strategy consisting of a maximum combination of three sampling time points with the latest sample drawn 3-6 h after MMF intake, whereas the remaining study tested all combinations of sampling times. MPA AUC12 was best predicted when three samples were taken at pre-dose and at 1 and 3 h post-dose with a mean bias and imprecision of 0.8 and 22.6 % for multiple linear regression analysis and of -5.5 and 23.0 % for maximum a posteriori (MAP) Bayesian analysis. Although mean bias was less when data were analysed using multiple linear regression, MAP Bayesian analysis is preferable because of its flexibility with respect to sample timing. Estimation of MPA AUC12 following EC-MPS administration using a limited sampling strategy with samples drawn within 3 h post-dose resulted in biased and imprecise results, likely due to a longer time to reach a peak MPA concentration (t max) with this formulation and more variable pharmacokinetic profiles. Inclusion of later sampling time points that capture enterohepatic recirculation and t max improved the predictive performance of strategies to predict EC-MPS exposure. Given the considerable pharmacokinetic variability associated with mycophenolate therapy, limited sampling strategies may potentially help in individualizing patient dosing. However, a compromise needs to be made between the predictive performance of the strategy and its clinical feasibility. An opportunity exists to combine research efforts globally to create an open-source database for MPA (AUC, concentrations and outcomes) that can be used and prospectively evaluated for AUC target-controlled dosing of MPA in autoimmune diseases

Comprehensive Versus Usual Community Care for First-Episode Psychosis: 2-Year Outcomes From the NIMH RAISE Early Treatment Program

The primary aim was to compare the impact of NAVIGATE, a comprehensive, multidisciplinary, team-based treatment approach for first episode psychosis designed for implementation in the U.S. healthcare system, to Community Care on quality of life

Cardiometabolic Risk in Patients With First-Episode Schizophrenia Spectrum Disorders: Baseline Results From the RAISE-ETP Study

IMPORTANCE: The fact that individuals with schizophrenia have high cardiovascular morbidity and mortality is well established. However, risk status and moderators or mediators in the earliest stages of illness are less clear. OBJECTIVE: To assess cardiometabolic risk in first-episode schizophrenia spectrum disorders (FES) and its relationship to illness duration, antipsychotic treatment duration and type, sex, and race/ethnicity. DESIGN, SETTING, AND PARTICIPANTS: Baseline results of the Recovery After an Initial Schizophrenia Episode (RAISE) study, collected between July 22, 2010, and July 5, 2012, from 34 community mental health facilities without major research, teaching, or clinical FES programs. Patients were aged 15 to 40 years, had research-confirmed diagnoses of FES, and had less than 6 months of lifetime antipsychotic treatment. EXPOSURE: Prebaseline antipsychotic treatment was based on the community clinician's and/or patient's decision. MAIN OUTCOMES AND MEASURES: Body composition and fasting lipid, glucose, and insulin parameters. RESULTS: In 394 of 404 patients with cardiometabolic data (mean [SD] age, 23.6 [5.0] years; mean [SD] lifetime antipsychotic treatment, 47.3 [46.1] days), 48.3% were obese or overweight, 50.8% smoked, 56.5% had dyslipidemia, 39.9% had prehypertension, 10.0% had hypertension, and 13.2% had metabolic syndrome. Prediabetes (glucose based, 4.0%; hemoglobin A1c based, 15.4%) and diabetes (glucose based, 3.0%; hemoglobin A1c based, 2.9%) were less frequent. Total psychiatric illness duration correlated significantly with higher body mass index, fat mass, fat percentage, and waist circumference (all P<.01) but not elevated metabolic parameters (except triglycerides to HDL-C ratio [P=.04]). Conversely, antipsychotic treatment duration correlated significantly with higher non-HDL-C, triglycerides, and triglycerides to HDL-C ratio and lower HDL-C and systolic blood pressure (all P≤.01). In multivariable analyses, olanzapine was significantly associated with higher triglycerides, insulin, and insulin resistance, whereas quetiapine fumarate was associated with significantly higher triglycerides to HDL-C ratio (all P≤.02). CONCLUSIONS AND RELEVANCE: In patients with FES, cardiometabolic risk factors and abnormalities are present early in the illness and likely related to the underlying illness, unhealthy lifestyle, and antipsychotic medications, which interact with each other. Prevention of and early interventions for psychiatric illness and treatment with lower-risk agents, routine antipsychotic adverse effect monitoring, and smoking cessation interventions are needed from the earliest illness phases

Prescription Practices in the Treatment of First-Episode Schizophrenia Spectrum Disorders: Data From the National RAISE-ETP Study

Treatment guidelines suggest distinctive medication strategies for first episode and multi-episode patients with schizophrenia. How much community clinicians adjust their usual treatment regimens for first episode patients is unknown. We examined prescription patterns and factors associated with prescription choice within a national cohort of early phase patients

Relax and try this instead: abbreviated habit reversal for maladaptive self-biting.

We evaluated the effectiveness of an abbreviated habit reversal procedure to reduce maladaptive oral self-biting in an adolescent boy in residential care. Treatment involved a combination of relaxation and two competing responses. Results of a withdrawal design and two posttreatment medical evaluations indicated that the intervention eliminated the biting and the tissue damage it caused

Exposure-effect relationship of mycophenolic acid and prednisolone in adult patients with lupus nephritis

The aim was to examine relationships between total and unbound mycophenolic acid (MPA) and prednisolone exposure and clinical outcomes in patients with lupus nephritis. METHODS: Six blood samples were drawn pre- and at 1, 2, 4, 6 and 8 h post-dose and total and unbound MPA and prednisolone pre-dose (C0 ), maximum concentration (Cmax ) and area under the concentration-time curve (AUC) were determined using non-compartmental analysis in 25 patients. The analyses evaluated drug exposures in relation to treatment response since starting MPA and drug-related adverse events. RESULTS: Dose-normalized AUC varied 10-, 8-, 7- and 19-fold for total MPA, unbound MPA, total prednisolone and unbound prednisolone, respectively. Median values (95% CI) of total MPA AUC(0,8 h) (21.5 [15.0, 42.0] vs. 11.2 [4.8, 30.0] mg l-1 h, P= 0.048) and Cmax (11.9 [6.7, 26.3] vs. 6.1 [1.6, 9.2] mg l-1 , P = 0.016) were significantly higher in responders than non-responders. Anaemia was significantly associated with higher total (37.8 [14.1, 77.5] vs. 18.5 [11.7, 32.7] mg l-1 h, P = 0.038) and unbound MPA AUC(0,12 h) (751 [214, 830] vs. 227 [151, 389] mg l-1 h, P = 0.004). Unbound prednisolone AUC(0,24 h) was significantly higher in patients with Cushingoid appearance (unbound: 1372 [1242, 1774] vs. 846 [528, 1049] nmol l-1 h, P = 0.019) than in those without. Poorer treatment response was observed in patients with lowest tertile exposure to both total MPA and prednisolone as compared with patients with middle and higher tertile exposure (17% vs. 74%, P = 0.023). CONCLUSIONS: This study suggests a potential role for therapeutic drug monitoring in individualizing immunosuppressant therapy in patients with lupus nephritis

Development of Improved Dosing Regimens for Mycophenolate Mofetil Based on Population Pharmacokinetic Analyses in Adults with Lupus Nephritis

Mycophenolic acid (MPA) provides effective treatment for lupus nephritis patients. Owing to its large pharmacokinetic variability, it is questionable whether standard fixed dose therapy can achieve optimal MPA exposure. The aim of this study was to develop a population pharmacokinetic model of MPA and its metabolite, 7-O-MPA-β-glucuronide (MPAG), to identify important covariate influences and better predict patient dosing requirements.MPA and MPAG concentration-time profiles were collected from 25 patients receiving mycophenolate mofetil (MMF) with or without cyclosporine (CsA) co-therapy. Samples were collected pre-dose and at 1, 2, 4, 6 and 8\ua0h post-dose on one or two occasions.A total of 225 and 226 concentration-time measurements of MPA and MPAG, respectively, were used to develop the model, utilizing NONMEM(®) software. A two-compartment model with first-order absorption and elimination for MPA and a one-compartment model with first-order elimination and enterohepatic circulation (EHC) for MPAG best described the data. Apparent clearance of MPAG (CL/F MPAG) significantly decreased with reducing renal function and extent of EHC was reduced with concomitant CsA use. Simulations using the final model showed that a 70-kg subject with a creatinine clearance of 90\ua0mL/min receiving concomitant CsA would require 1.25\ua0g of MMF twice daily while a similar subject who did not receive concomitant CsA would require 0.75\ua0g twice daily to achieve a MPA area under the concentration-time curve from 0 to 12\ua0h (AUC0-12) of 45\ua0mg·h/L.A 'tiered' dosing approach considering patient renal function and CsA co-therapy, rather than a 'one dose fits all' approach, would help individualize MMF therapy in adult lupus nephritis patients to ensure more patients have optimal MPA exposure

Antecedent manipulations in a tangible condition: effects of stimulus preference on aggression.

After a functional analysis indicated that aggression of an 8-year-old boy with autism was maintained by access to preferred items, antecedent manipulations involving the relative preference of restricted and noncontingently available stimuli were conducted. Restricting highly preferred items evoked the highest rates of aggression regardless of the preference level of the noncontingently available alternative items. Restricting less preferred stimuli was associated with moderate rates of aggression even when the alternative items were more preferred

Variable-ratio conditioning history produces high- and low-rate fixed-interval performance in rats.

Four rats were exposed to an A-B-A-B series of 30 sessions each of variable-ratio 20 (A) and fixed-interval 30-s (B) schedules. Four other rats received 120 sessions of fixed-interval 30 s. The rats with a history of variable-ratio responding subsequently showed primarily high or low response-rate patterns on the fixed-interval schedule without evidence of classical scalloping (i.e., increased rates of responding throughout the interreinforcement interval), except infrequently in 1 rat. The rats exposed to only the fixed-interval 30-s schedule displayed the expected sequence of scalloping giving way to lower rate break-run or simply low-rate responding over time. This experiment shows that when naive rats are exposed to even a simple history of reinforcement (in this case, a variable-ratio 20), their subsequent fixed-interval performance is very different from comparable performance in naive rats, and might be said to be more similar to the responding of adult humans. The argument is made that care should be taken in comparing the fixed-interval performance of humans and nonhumans because humans have a complex history of reinforcement, whereas laboratory nonhumans are typically naive