Anticoagulation Monitoring and Targets: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic-review informed, modified Delphi consensus regarding anticoagulation monitoring assays and target levels in pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE. DATA SOURCES: A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021. STUDY SELECTION: Anticoagulation monitoring of pediatric patients on ECMO. DATA EXTRACTION: Two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool or the revised Cochrane risk of bias for randomized trials, as appropriate and the evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for clinical recommendations focused on anticoagulation monitoring and targets, using a web-based modified Delphi process to build consensus (defined as > 80% agreement). One weak recommendation, two consensus statements, and three good practice statements were developed and, in all, agreement greater than 80% was reached. We also derived some resources for anticoagulation monitoring for ECMO clinician use at the bedside. CONCLUSIONS: There is insufficient evidence to formulate optimal anticoagulation monitoring during pediatric ECMO, but we propose one recommendation, two consensus and three good practice statements. Overall, the available pediatric evidence is poor and significant gaps exist in the literature.

Monitoring levetiracetam concentration in saliva during pregnancy is stable and feasible.

AIMS: This multicenter prospective cohort study (registration no. ChiCTR2000032089) aimed to investigate the relationship between saliva and plasma levetiracetam concentrations to determine whether saliva could be used for routine monitoring of levetiracetam during pregnancy. METHODS: The slot concentrations of levetiracetam in simultaneously obtained saliva and plasma samples were measured using UPLC-MS/MS. The correlations between saliva and plasma levetiracetam concentrations and the dose-normalized concentrations were compared among pregnant women in different stages and nonpregnant control participants with epilepsy. RESULTS: In total, 231 patients with 407 plasma and saliva sample pairs were enrolled from 39 centers. Linear relationships between salivary and plasma levetiracetam concentrations were reported in the enrolled population (r = 0.898, p < 0.001), including pregnant (r = 0.935, p < 0.001) and nonpregnant participants (r = 0.882, p < 0.001). Plasma concentrations were moderately higher than saliva concentrations, with ratios of saliva to plasma concentrations of 0.98 for nonpregnant women, 0.98, 1, and 1.12 for pregnant women during the first trimester, the second trimester, the and third trimester, respectively. The effective range of saliva levetiracetam concentration was found to be 9.98 µg/mL (lower limit) with an area under the curve (AUC) of 0.937 (95% confidence intervals, 0.915-0.959), sensitivity of 88.9%, specificity of 86.8%, and p < 0.001, to 24.05 µg/mL (upper limit) with an AUC of 0.952 (0.914-0.99), sensitivity of 100%, specificity of 92.3%, and p = 0.007. CONCLUSION: The saliva/plasma concentration ratio of levetiracetam remains constant during pregnancy and is similar to that in non-pregnant individuals. Monitoring levetiracetam concentration in saliva during pregnancy should be widely promoted.

Relevance of plasma lenvatinib concentrations and endogenous urinary cytochrome P450 3A activity biomarkers in clinical practice.

Lenvatinib (LEN), a multitarget tyrosine kinase inhibitor used in various cancer treatments, is mainly metabolized by cytochrome P450 3A (CYP3A) enzymes. The importance of therapeutic drug monitoring (TDM) in patients administered LEN has been proposed. Although some biomarkers of endogenous CYP3A activity have been reported, their utility in dosage adjustments has not been well evaluated. This study investigated the correlation between plasma LEN concentrations and endogenous urinary CYP3A biomarkers in clinical practice. Concentrations of plasma LEN (N = 225) and CYP3A biomarkers (cortisol, 6ß-hydroxycortisol, deoxycholic acid, and 1ß-hydroxydeoxycholic acid) in urine (N = 214) from 20 patients (hepatocellular carcinoma, N = 6; thyroid cancer, N = 3; endometrial cancer, N = 8; and renal cell carcinoma, N = 3) collected for consultation for up to 1 year were evaluated using liquid chromatography-tandem mass spectrometry. Moreover, plasma trough LEN concentrations were predicted using a three-compartment model with linear elimination for outpatients administered LEN before sample collection. Moderate correlations were observed between the quantified actual concentrations and the predicted trough concentrations of LEN, whereas there was no correlation with endogenous urinary CYP3A biomarkers. The utility of endogenous urinary CYP3A biomarkers could not be determined. However, TDM for outpatients administered orally available medicines may be predicted using a nonlinear mixed effect model (NONMEM). This study investigated the utility of endogenous urinary CYP3A biomarkers for personalized medicine and NONMEM for predicting plasma trough drug concentrations. These findings will provide important information for further clinical investigation and detailed TDM.

The Black Book of Psychotropic Dosing and Monitoring.

Introduction Since the last edition of the Black Book, several innovative agents have been approved or are poised to be approved in the coming year. These include novel antidepressants, the first muscarine agonist for the treatment of schizophrenia, the first psychedelic which may be approved for the treatment of PTSD (Post Traumatic Stress Disorder), and the first disease modifying drug for the treatment of Alzheimer's disease. Three new antidepressants have come to the market in the past 18 months. The first of those, Auvelity, the combination of bupropion and dextromethorphan, takes advantage of a pharmacokinetic and pharmacodynamic synergism between the two drugs.85 Dextromethorphan has several pharmacodynamic properties including actions on the NMDA receptor and the Sigma 1 receptor, adding to the indirect norepinephrine agonist properties of bupropion. How Dextromethorphan is rapidly metabolized via the CYP2D6 isoenzyme to dextrophan that may have mu opioid agonist properties. The combination with bupropion, a CYP2D6 inhibitor, inhibits the metabolism of dextromethorphan allowing for more consistent therapeutic levels. The combination of dextromethorphan 45 mg twice per day and bupropion SR 105 mg twice daily appears to be more effective than an equivalent dose of bupropion alone both in speeding up antidepressant response and achieving remission. However, it's not clear at this time how the combination would compare with a more typical dose of bupropion of 300-450 milligrams a day range. The phase III program for Auvelity, showed that the drug was well tolerated with the most common side effects being dizziness, headache, and dry mouth.86 Another novel antidepressant agent approved in 2023 is zuranolone (Zurzuvae). Zuranolone is an oral analog of IV brexanalone, and like brexanolone, was approved for the treatment of post-partum depression.83 The advantages of zuranolone over brexanalone are many. While brexanolone is a 60-hour intravenous infusion that must be administered in a health care facility, zuranolone is a once/day oral medication that is usually taken at home. Like brexanolone, and unlike most antidepressants, zuranolone has a short course of treatment, lasting just 14 days. Zuranolone's, as does brexanolone, is thought to act primarily as allosteric modulator of the GABA-a receptors. Despite only 14 days of treatment, zuranolone produced in depression in post-partum patients a clinically and significantly meaningful improvement at day 15 and continued to day 45 or 1 month past the end of treatment. Zuranolone is a schedule IV drug. The most common side effect in clinical trials was somnolence with 36% of participants reporting this side effect vs only 6% of those on placebo.84 Other common side effects included dizziness, diarrhea and fatigue. While the FDA declined to approve zuranolone as monotherapy or as an adjunctive treatment to standard antidepressants in major depression itself, there are positive studies in non-post-partum major depression albeit with smaller effect sizes and less consistent duration of activity. It is likely that zuranolone will continue to be studied in other depressive syndromes such as depression with anxious distress. The third "new" antidepressant approved late 2023 was gepirone (Exxua). Gepirone is not exactly a new or novel antidepressant and originally sought approval in the US about 20 years ago.88 There had been two positive studies of gepirone during the original NDA application but also a number of failed, negative, or non-informative studies as well. Thus, the FDA declined to originally approve the drug. However, failed and negative trials are common with antidepressants and after much internal debate, the FDA ultimately agreed to approve the drug based on the positive trials and a relatively favorable side effect profile. Gepirone, like buspirone, is a partial agonist of the 5HT1a receptor and a 5HT2 antagonist. As such, gepirone does not tend to be associated with sexual side effects, weight gain, or sedation. The most common side effects are dizziness, nausea, and insomnia which tend to improve in many patients over time. Second generation antipsychotics (SGAs) continue to be the only class of agents [other than esketamine (Spravato)] approved in adjunctive treatment of resistant major depression. In addition to olanzapine (combined with fluoxetine; Symbyax), aripiprazole (Abilify), quetiapine (Seroquel), brexpiprazole (Rexulti), cariprazine (Vraylar) became the latest SGA to be approved in 2022.90 Adjunctive cariprazine at 1.5 mg daily was significantly more effective than adjunctive placebo in patients with MDD who had failed to achieve an adequate response with an antidepressant alone after 6 weeks of treatment. Interestingly, a 3 mg dose of cariprazine was less consistently effective.91 The major advantage of cariprazine over some of the other approved adjunctive SGA's is easy dosing, with the starting 1.5 mg dose being the optimal therapeutic dose for most people, and a lower metabolic side effect burden with most subjects having limited or no weight gain in short term trials. The most common side effect were akathisia/restlessness, fatigue, and nausea. Lumateperone (Caplyta) is also has positive phase III data in the adjunctive treatment of major depression and is expective file for approval in late 2024. Another recent major development in psychopharmacology is the reemergence of psychedelics in the treatment of psychiatric disorders. The first of these is MDMA (phenethylamine 3,4-methylenedioxymethamphetamine) assisted psychotherapy for the treatment of PTSD. A New Drug Application (NDA) was accepted by the FDA for MDMA in the treatment of PTSD in late 2023.87 Because the drug is being fast tracked as a "breakthrough" treatment by the FDA, it was expected to see approval in the summer of 2024. The phase II and III data for MDMA assisted psychotherapy in the treatment of PTSD have been quite consistent and impressive. However, independent reviews have pointed to significant deficiencies in these studies including the bias introduced because of functional unblinding; virtually all patients in psychedelic studies can guess whether they got the active drug or placebo. The functional unblinding, the lack of standardization of adjunctive psychotherapy as well as the abuse potential of MDMA, may delay an FDA approval. The typical regimen in these trials included 3 preparatory psychotherapy sessions followed by once/month dosing sessions (lasting about 8 hours) and using doses of 120-160 mg in a split dose. There were typically 3 monthly dosing sessions, each followed by 3 integrative psychotherapy sessions to help subjects process and understand their experiences during the dosing sessions. In the most recent phase 3 trials, over 70% of subjects no longer met criteria for PTDS compared to 46% of those treated with psychotherapy and placebo alone.89 The only approved medications for treating PTSD are two SSRIs, paroxetine and sertraline. These drugs effect only some dimensions of PTSD with only 20-30% achieving a remission level response with these drugs. Thus, MDMA assisted psychotherapy appears to achieve much higher levels of remission and response than has been true for the SSRIs. Since MDMA is not taken continuously, side effects from MDMA tend to be short lived. Side effects have included muscle tightness, nausea, diminished appetite, excessive sweating, feeling cold and dizziness among others. Since MDMA is currently a schedule I drug, it is likely that a rigorous Risk Evaluation Mitigation (REMs) program will be put in place and a limited number of centers and clinicians will be designated to perform MDMA assisted psychotherapy for PTSD. In addition to MDMA, psilocybin-assisted psychotherapy is in phase 3 trials for treating resistant depression but unlikely to be available before late 2025 at the earliest. An argument can be made that there has not been a truly novel antipsychotic since the introduction of clozapine in the US in 1990. All first-generation antipsychotics have been dopamine 2 antagonists and second-generation drugs have involved some ratio of 5HT2 antagonism to D2 blockade. In 2023, the FDA accepted the application of xenomaline/tropsium (KarXT) which may become the first muscarinic M1M4 agonist approved for the treatment of schizophrenia.82,83 Tropsium is added as a muscarine antagonist to block the peripheral cholinergic effects of a muscarine agonist. Xenomaline/tropsium appears to be effective in treating both positive and negative symptoms of schizophrenia. In a phase 3 study of 407 patients with schizophrenia, xenomaline/tropsium at doses of xenomaline/50 mg/tropsium 20 mg twice daily up to 125 mg/30 mg twice daily was significantly more effective than placebo in treating both and negative symptoms over 5 weeks of treatment. As would be expected, the side effect profile of xenomaline/tropsium is very different that all currently available antipsychotics. There is no risk of EPS as it is not a dopamine antagonist, and xenomaline/tropsium is not associated with significant metabolic effects. The side effects are cholinergic in nature and include constipation, dry mouth, and nausea. A decision is expected in September of 2024. The year 2023 also saw the approval of the first disease modifying drug in the treatment of Alzheimer's disease, lecanemab (Lequembi). While acetylcholinesterase inhibitors and memantine have been available for decades, these drugs modestly improve cognition in Alzheimer's disease patients and do not alter the progressive course of the illness. Lecanemab is an IV monoclonal antibody that targets the removal of beta-amyloid in the brain as well proto-fibrils that are also known to be toxic to neuronal tissue. When given early in the course of the illness, patients treated with Lecanemab showed 27% less decline on some measures of cognition and function thandid patients treated with a placebo over 18 months (about 1 and a half years). It is not known whether treatment for longer than 18 months would show lesser or greater decline over time. However, there are simulation studies that suggest that Lecanemab may modestly reduce the number of patients who progress to severe Alzheimer's disease and require institutional care. The standard dose is 10 mg/kg given via IV over one hour every 2 weeks for 18 months. Lecanemab is typically administered in an infusion center so that side effects can be monitored. The most serious side effects of Lecanemab are amyloid related imaging abnormalities (ARIA) that are associated with brain edema and microhemorrhages. ARIA can occur in up to 15% of patients. More common side effects are headache and nausea. While it remains to be seen how useful these new agents will be in clinical practice, they do represent an approach to treating neuropsychiatric disorders that are a notable departure from the pharmacotherapy of the past half century. It seems likely that some patients who have not been able to respond to or tolerate traditional pharmacotherapy will find hope in these new medications.

The Effect of Real-Time Medication Monitoring-Based Digital Adherence Tools on Adherence to Antiretroviral Therapy and Viral Suppression in People Living With HIV: A Systematic Literature Review and Meta-Analysis.

BACKGROUND: Universal antiretroviral therapy (ART) has led to improved treatment outcomes in persons living with HIV. Adherence to ART is required to achieve viral suppression. Real-time medication monitoring (RTMM)-based digital adherence tools (DATs) could be effective in improving ART adherence and viral suppression in persons living with HIV. OBJECTIVES: The primary and secondary objectives of this review were to assess the effect of RTMM-based DATs on improving ART adherence and viral load suppression. METHODS: We searched MEDLINE, Embase, and Global Health for publications published through October 11, 2022. Narrative synthesis and random effects meta-analyses were conducted to synthesize the results. RESULTS: Of 638 papers identified, 8 were included. Six studies were randomized controlled trials (RCTs), and 2 were cohort studies. Two studies, an RCT in China (mean adherence: 96.2% vs 89.1%) and a crossover cohort study in Uganda (mean adherence: 84% vs 93%), demonstrated improved ART adherence. No studies demonstrated improved viral suppression. In the meta-analyses, we estimated that RTMM-based digital adherence tools had a statistically insignificant small positive effect on ART adherence and viral suppression with a standardized mean difference of 0.1922 [95% CI: -0.0268 to 0.4112, P-value: 0.0854] and viral suppression with an odds ratio of 1.3148 [95% CI: 0.9199 to 1.8791, P-value: 0.1331]. CONCLUSIONS: Our meta-analyses found that RTMM-based DATs did not have a significant effect on ART adherence and viral suppression. However, due to few published studies available, heterogeneity of target populations, intervention designs, and adherence measurement instruments, more data are required to provide conclusive evidence.

Development and validation of an LC-MS/MS method for ruxolitinib quantification: advancing personalized therapy in hematologic malignancies.

Background: Hematologic malignancies such as leukemia and lymphoma present treatment challenges due to their genetic and molecular heterogeneity. Ruxolitinib, a Janus kinase (JAK) inhibitor, has demonstrated efficacy in managing these cancers. However, optimal therapeutic outcomes are contingent upon maintaining drug levels within a therapeutic window, highlighting the necessity for precise drug monitoring. Methods: We developed a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify ruxolitinib in human plasma, improving upon traditional methods in specificity, sensitivity, and efficiency. The process involved the use of advanced chromatographic techniques and robust mass spectrometric conditions to ensure high accuracy and minimal matrix effects. The study was conducted using samples from 20 patients undergoing treatment, with calibration standards ranging from 10 to 2000 ng/mL. Results: The method displayed linearity (R 2 > 0.99) across the studied range and proved highly selective with no significant interference observed. The method's precision and accuracy met FDA guidelines, with recovery rates consistently exceeding 85%. Clinical application demonstrated significant variability in ruxolitinib plasma levels among patients, reinforcing the need for individualized dosing schedules. Conclusion: The validated LC-MS/MS method offers a reliable and efficient tool for the therapeutic drug monitoring of ruxolitinib, facilitating personalized treatment approaches in hematologic malignancies. This approach promises to enhance patient outcomes by optimizing dosing to reduce toxicity and improve efficacy.

Switching from Dose-Intensified intravenous to SubCutaneoUS infliximab in Inflammatory Bowel Disease (DISCUS-IBD): protocol for a multicentre randomised controlled trial.

INTRODUCTION: A substantial proportion of patients with inflammatory bowel disease (IBD) on intravenous infliximab require dose intensification. Accessing additional intravenous infliximab is labour-intensive and expensive, depending on insurance and pharmaceutical reimbursement. Observational data suggest that subcutaneous infliximab may offer a convenient and safe alternative to maintain disease remission in patients requiring dose-intensified infliximab. A prospective, controlled trial is required to confirm that subcutaneous infliximab is as effective as dose-intensified intravenous infliximab, to identify predictors of disease flare and to establish the role of subcutaneous infliximab therapeutic drug monitoring. METHODS AND ANALYSIS: The DISCUS-IBD trial is an investigator-initiated, prospective, multicentre, randomised, open-label non-inferiority study comparing the rate of disease flares in participants randomised to continue dose-intensified intravenous infliximab to those switched to subcutaneous infliximab after 48 weeks. Participants are adult patients with IBD in sustained corticosteroid-free remission on any regimen of dose-intensified infliximab up to a maximum of 10 mg/kg 4-weekly intravenously. Participants allocated to intravenous infliximab will continue infliximab at the same dose-intensified regimen they were receiving at study enrolment. Subcutaneous infliximab dosing will be stratified by prior intravenous infliximab dosing. Clinical (Harvey-Bradshaw Index, partial Mayo score), biochemical (C reactive protein, faecal calprotectin), pharmacokinetic (drug-level±antidrug antibodies) and qualitative data are collected 12-weekly until study conclusion at week 48. 13 sites across Australia will participate in recruitment to reach a calculated sample size of 120 participants. ETHICS AND DISSEMINATION: Multisite ethics approval was obtained from the Health District Human Research Ethics Committee (HREC) at The Alfred Hospital under a National Mutual Acceptance (NMA) agreement (HREC/90559/Alfred-2022; Local Reference: Project 618/22, version 1.6, 2 March 2023). Findings will be reported at national and international gastroenterology meetings and published in peer-reviewed journals. DISCUS-IBD was prospectively registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR) prior to commencing recruitment. TRIAL REGISTRATION NUMBER: ACTRN12622001458729.

Use of the DMAIC Lean Six Sigma quality improvement framework to improve beta-lactam antibiotic adequacy in the critically ill.

Beta-lactam antibiotics are widely used in the intensive care unit due to their favorable effectiveness and safety profiles. Beta-lactams given to patients with sepsis must be delivered as soon as possible after infection recognition (early), treat the suspected organism (appropriate), and be administered at a dose that eradicates the infection (adequate). Early and appropriate antibiotic delivery occurs in >90% of patients, but less than half of patients with sepsis achieve adequate antibiotic exposure. This project aimed to address this quality gap and improve beta-lactam adequacy using the Define, Measure, Analyze, Improve, and Control Lean Six Sigma quality improvement framework. A multidisciplinary steering committee was formed, which completed a stakeholder analysis to define the gap in practice. An Ishikawa cause and effect (Fishbone) diagram was used to identify the root causes and an impact/effort grid facilitated prioritization of interventions. An intervention that included bundled education with the use of therapeutic drug monitoring (TDM; i.e. drug-level testing) was projected to have the highest impact relative to the amount of effort and selected to address beta-lactam inadequacy in the critically ill. The education and TDM intervention were deployed through a Plan, Do, Study, Act cycle. In the 3 months after "go-live," 54 episodes of beta-lactam TDM occurred in 41 unique intensive care unit patients. The primary quality metric of beta-lactam adequacy was achieved in 94% of individuals after the intervention. Ninety-four percent of clinicians gauged the education provided as sufficient. The primary counterbalance of antimicrobial days of therapy, a core antimicrobial stewardship metric, was unchanged over time (favorable result; P = .73). Application of the Define, Measure, Analyze, Improve, and Control Lean Six Sigma quality improvement framework effectively improved beta-lactam adequacy in critically ill patients. The approach taken in this quality improvement project is widely generalizable to other drugs, drug classes, or settings to increase the adequacy of drug exposure.

Optimizing vancomycin therapeutic drug monitoring compliance in pediatric oncology: towards personalized medication management.

Aim: Vancomycin, a crucial treatment for Gram-positive bacteria, necessitates therapeutic drug monitoring (TDM) to prevent treatment failures. We investigated the healthcare professional's compliance toward TDM of vancomycin recommendations and follow-up levels. Materials & methods: We collected data from 485 patients who received vancomycin in the Children's Cancer Hospital Egypt 57357 medical records system (Cerner) over 4 months, from January to April 2020. Results: Our data shows that only 54% of patients had TDM requests from healthcare professionals for the total patients who received vancomycin treatment. The healthcare professionals' compliance with the recommendations was 91.7%, while the follow-up levels were 66.7%. Conclusion: While overall adherence to recommendations is strong, enhancing compliance with follow-up levels remains a priority for improvement.

[Box: see text].

A rapid LC-MS/MS method for the simultaneous quantification of ivacaftor, lumacaftor, elexacaftor, tezacaftor, hexyl-methyl ivacaftor and ivacaftor carboxylate in human plasma.

Cystic fibrosis is one of the most common genetic diseases among caucasian population. This disease is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene encoding for the CFTR protein. Lumacaftor, elexacaftor, tezacaftor, and ivacaftor were currently used as the treatment to Cystic fibrosis. In this study, we describe a new method for the simultaneous quantification of four molecules: lumacaftor, elexacaftor, tezacaftor, and ivacaftor, alongside two metabolites of ivacaftor, specifically hexyl-methyl ivacaftor and ivacaftor carboxylate by liquid chromatography-tandem mass spectrometry. This method holds significant utility for therapeutic drug monitoring and the optimization of treatments related to CFTR modulators. Molecules were extracted from 100 µL of plasma by a simple method of protein precipitation using acetonitrile. Following extraction, chromatographic separation was carried out by reverse chromatography on a C18 analytical column, using a gradient elution of water (0.05 % formic acid, V/V) and acetonitrile (0.05 % formic acid, V/V). The run time was 7 minutes at a flow rate of 0.5 mL/min. After separation, molecules were detected by electrospray ionization on a Xevo TQD triple-quadrupole-mass-spectrometer (Waters®, Milford, USA). The calibration range were: 0.053-20.000 mg/L for elexacaftor, tezacaftor and lumacaftor, 0.075-14.000 mg/L for ivacaftor, and 0.024-6.500 mg/L for hexyl-methyl ivacaftor and ivacaftor carboxylate. The proposed method underwent throughout validation demonstrating satisfactory precision (inter- and intra-day coefficients of variation less than 14.3 %) and a good accuracy (inter- and intra-day bias ranging between -13.7 % and 14.7 %) for all the analytes. The presented method for the simultaneous quantification of CFTR modulators and their metabolites in human plasma has undergone rigorous validation process yielding good results including strong precision and accuracy for all analytes. This method has been effectively used in routine analytical analysis and clinical investigations within our laboratory.

Improved high-performance liquid chromatography tandem mass spectrometry method for quantification of infliximab in pediatric plasma and its application in therapeutic drug monitoring.

RATIONALE: The application of infliximab (IFX) to immune-mediated disease is limited by the significant individual variability and associated clinical nonresponse, emphasizing the importance of therapeutic drug monitoring (TDM). Because of the cross-reactivity, limited linear range, and high costs, the clinical application of the previous reported methods was limited. Here, an improved high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed to address the issues. METHODS: This study developed an improved bioanalytical HPLC-MS/MS method coupling nanosurface and molecular-orientation limited proteolysis technology. The commercially available compound P14R was selected as the internal standard. This method was developed with fewer volume of reagents and was thoroughly validated. The validated method was applied to TDM in pediatric inflammatory bowel disease (IBD). RESULTS: Chromatography was performed using a Shim-pack GISS-HP C18 metal-free column (3 µm, 2.1 × 100 mm) with a gradient elution of 0.1% formic acid in water and acetonitrile at 0.4 mL/min. Detection and quantitation were performed using electrospray ionization (ESI) and multiple reaction monitoring in the positive ion mode. The method was validated to demonstrate its selectivity, linearity, accuracy, precision, recovery, matrix effect, and stability. The method exhibited a linear dynamic range of 0.3-100 µg/mL, with intra- and inter-day precision and relative errors below 15%. The recovery and matrix effect were measured as 87.28%-89.72% and 41.98%-67.17%, respectively, which were effectively compensated by the internal standard. A total of 32 samples collected from 24 pediatric patients with IBD were analyzed using the validated method, and only 46.9% achieved the reported targeted trough level. CONCLUSION: This study developed an improved HPLC-MS/MS method for the quantitative determination of IFX concentration in human plasma. The accurate, reliable, and cost-effective method was validated and utilized in the analysis of clinical samples. The results confirmed the importance of TDM on IFX and the clinical application prospects of the improved method.

Approach to loss of response to advanced therapies in inflammatory bowel disease.

BACKGROUND: Remarkable progress over the last decade has equipped clinicians with many options in the treatment of inflammatory bowel disease. Clinicians now have the unique opportunity to provide individualized treatment that can achieve and sustain remission in many patients. However, issues of primary non-response (PNR) and secondary loss of response (SLOR) to non-tumour necrosis factor inhibitor (TNFi) therapies remains a common problem. Specific issues include the choice of optimization of therapy, identifying when dose optimization will recapture response, establishing optimal dose for escalation and when to switch therapy. AIM: To explores the issues of PNR and SLOR to non-TNFi therapies. METHODS: This review explores the current evidence and literature to elucidate management options in cases of PNR/SLOR. It will also explore potential predictors for response following SLOR/PNR to therapies including the role of therapeutic drug monitoring (TDM). RESULTS: In the setting of PNR and loss of response to alpha-beta7-integrin inhibitors and interleukin (IL)-12 and IL-23 inhibitors dose optimization is a reasonable option to capture response. For Janus kinase inhibitors dose optimization can be utilized to recapture response with loss of response. CONCLUSION: The role of TDM in the setting of advanced non-TNFi therapies to identify patients who require dose optimization and as a predictor for clinical remission is not yet established and this remains an area that should be addressed in the future.

Study protocol for ADAPT-TDM: A beta-lactam antibiotic Dose AdaPtation feasibility randomised controlled Trial using Therapeutic Drug Monitoring.

INTRODUCTION: Critically ill patients are at risk of suboptimal beta-lactam antibiotic (beta-lactam) exposure due to the impact of altered physiology on pharmacokinetics. Suboptimal concentrations can lead to treatment failure or toxicity. Therapeutic drug monitoring (TDM) involves adjusting doses based on measured plasma concentrations and individualising dosing to improve the likelihood of improving exposure. Despite its potential benefits, its adoption has been slow, and data on implementation, dose adaptation and safety are sparse. The aim of this trial is to assess the feasibility and fidelity of implementing beta-lactam TDM-guided dosing in the intensive care unit setting. METHODS AND ANALYSIS: A beta-lactam antibiotic Dose AdaPtation feasibility randomised controlled Trial using Therapeutic Drug Monitoring (ADAPT-TDM) is a single-centre, unblinded, feasibility randomised controlled trial aiming to enroll up to 60 critically ill adult participants (≥18 years). TDM and dose adjustment will be performed daily in the intervention group; the standard of care group will undergo plasma sampling, but no dose adjustment. The main outcomes include: (1) feasibility of recruitment, defined as the number of participants who are recruited from a pool of eligible participants, and (2) fidelity of TDM, defined as the degree to which TDM as a test is delivered as intended, from accurate sample collection, sample processing to result availability. Secondary outcomes include target attainment, uptake of TDM-guided dosing and incidence of neurotoxicity, hepatotoxicity and nephrotoxicity. ETHICS AND DISSEMINATION: This study has been approved by the Alfred Hospital human research ethics committee, Office of Ethics and Research Governance (reference: Project No. 565/22; date of approval: 22/11/2022). Prospective consent will be obtained and the study will be conducted in accordance with the Declaration of Helsinki. The finalised manuscript, including aggregate data, will be submitted for publication in a peer reviewed journal. ADAPT-TDM will determine whether beta-lactam TDM-guided dose adaptation is reproducible and feasible and provide important information required to implement this intervention in a phase III trial. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry, ACTRN12623000032651.

Evaluating the Clinical Impact and Feasibility of Therapeutic Drug Monitoring of Pazopanib in a Real-World Soft-Tissue Sarcoma Cohort.

INTRODUCTION AND OBJECTIVE: Pazopanib is registered for metastatic renal cell carcinoma and soft-tissue sarcoma (STS). Its variable pharmacokinetic (PK) characteristics and narrow therapeutic range provide a strong rationale for therapeutic drug monitoring (TDM). Prior studies have defined target levels of drug exposure (≥ 20.5 mg/L) linked to prolonged progression-free survival (PFS), but the added value of using TDM remains unclear. This study investigates the effect of TDM of pazopanib in patients with STS on survival outcomes and dose-limiting toxicities (DLTs) and evaluates the feasibility of TDM-guided dosing. METHODS: A TDM-guided cohort was compared to a non-TDM-guided cohort for PFS, overall survival (OS) and DLTs. PK samples were available from all patients, though not acted upon in the non-TDM-guided cohort. We evaluated the feasibility of TDM by comparing the proportion of underdosed patients in our TDM cohort with data from previous publications. RESULTS: A total of 122 STS patients were included in the TDM-guided cohort (n = 95) and non-TDM-guided cohort (n = 27). The average exposure in the overall population was 30.5 mg/L and was similar in both groups. Median PFS and OS did not differ between the TDM-guided cohort and non-TDM-guided cohort (respectively 5.5 vs 4.4 months, p = 0.3, and 12.6 vs 10.1 months, p = 0.8). Slightly more patients in the non-TDM-guided cohort experienced DLTs (54%) compared to the TDM-guided cohort (44%). The proportion of underdosed patients (13.3%) was halved compared to historical data (26.7%). CONCLUSION: TDM reduced the proportion of patients with subtherapeutic exposure levels by ~ 50%. Nonetheless, the added value of TDM for achieving target trough levels of ≥ 20.5 mg/L for pazopanib on survival outcomes could not be confirmed in STS patients.

Immune responsiveness in stable kidney transplantation patients: Complete inhibition of T-cell proliferation but residual T-cell activity during maintenance immunosuppressive treatment.

The recommended immunosuppressive treatment after kidney transplantation consists of tacrolimus, mycophenolate mofetil, and low-dose corticosteroids. Drug concentrations are monitored using therapeutic drug monitoring (TDM), which does not necessarily correlate with pharmacodynamic activity. To find the balance between optimal efficacy and minimal toxicity, it might be more informative to monitor patients' immunological status rather than drug concentrations. We selected a panel of T-cell-based immune assays, which were used for immunomonitoring of 14 stable kidney transplantation patients. Whole blood was incubated with a T-cell stimulus, after which T-cell proliferation, T-cell activation marker expression and cytokine production were measured to study residual immune activity in vitro (before drug intake; drug added to the incubation) and ex vivo (after drug intake). T-cell proliferation was completely suppressed in all patients over the full day, while IL-2, IFN-γ, CD71, and CD154 showed fluctuations over the day with a strong inhibition (75%-25%) at 2 h post-dose. The level of inhibition was variable between patients and could not be related to pharmacokinetic parameters or the presence of regulatory or senescence immune cells. Moreover, the level of inhibition did not correlate with the in vitro tacrolimus drug effect as studied by incubating pre-dose blood samples with additional tacrolimus. Overall, IL-2, IFN-γ, CD71, and CD154 seem to be good markers to monitor residual immune activity of transplantation patients. To evaluate the correlation between these pharmacodynamic biomarkers and clinical outcome, prospective observational studies are needed.

[The Application Study of Voriconazole and Its Metabolites Concentration Monitoring in Allogeneic Hematopoietic Stem Cell Transplantation Patients].

OBJECTIVE: To explore the application value of simultaneous monitoring of voriconazole (VRCZ) and voriconazole N-oxide (VNO) in efficacy and safety of VRCZ in the prevention and treatment of fungal infections in allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients before engraftment (i.e., days +1 to +30 after transplantation). METHODS: The influencing factors of VRCZ, VNO concentration and MR (CVNO/CVRCZ) and the difference of VRCZ in the prevention and treatment of fungal infection and liver and kidney injury were analyzed. The receiver operating characteristic curve (ROC) was used to analyze the differences (the corresponding to the maximum of the Youden index on the curve was set as the cut-off value) to confirm the critical value. RESULTS: The factors affecting VRCZ concentration (CVRCZ), VNO concentration (CVNO) and MR were patient weight, VRCZ daily dose, and transplantation type (all P < 0.05). CVRCZ and CVNO in the effective group were higher than those in the ineffective group (P < 0.001), the opposite of MR (P < 0.001); the liver and renal injury group had lower MR than the normal group (P < 0.05). ROC showed that CVRCZ, C VNO and MR had important value in predicting VRCZ in the prevention and treatment of invasive fungal infections in allo-HSCT patients before engraftment, and their cutoff of concentrations were 0.95 µg/ml, 1.35 µg/ml and 1.645, respectively (AUC: 0.9677, 0.7634, 0.9564). CVRCZ and MR can assist in indicating liver ï¼»cutoff values: 0.65 µg/ml, 1.96 (AUC: 0.5971, 0.6663)ï¼½ and renal injury ï¼»cutoff values: 0.95 µg/ml, 1.705 (AUC: 0.6039, 0.6164)ï¼½. CONCLUSION: The great value of simultaneous monitoring of VRCZ, VNO and MR can predict in the efficacy and safety of VRCZ in allo-HSCT patients before engraftment. The prediction accuracy of CVRCZ was higher than that of MR, followed by that of CVNO. Increased CVRCZ and decreased MR increase the risk of liver and kidney injury.

Pharmacogenetic Testing or Therapeutic Drug Monitoring: A Quantitative Framework.

BACKGROUND: Pharmacogenetic profiling and therapeutic drug monitoring (TDM) have both been proposed to manage inter-individual variability (IIV) in drug exposure. However, determining the most effective approach for estimating exposure for a particular drug remains a challenge. This study aimed to quantitatively assess the circumstances in which pharmacogenetic profiling may outperform TDM in estimating drug exposure, under three sources of variability (IIV, inter-occasion variability [IOV], and residual unexplained variability [RUV]). METHODS: Pharmacokinetic models were selected from the literature corresponding to drugs for which pharmacogenetic profiling and TDM are both clinically considered approaches for dose individualization. The models were used to simulate relevant drug exposures (trough concentration or area under the curve [AUC]) under varying degrees of IIV, IOV, and RUV. RESULTS: Six drug cases were selected from the literature. Model-based simulations demonstrated that the percentage of patients for whom pharmacogenetic exposure prediction is superior to TDM differs for each drug case: tacrolimus (11.0%), tamoxifen (12.7%), efavirenz (49.2%), vincristine (49.6%), risperidone (48.1%), and 5-fluorouracil (5-FU) (100%). Generally, in the presence of higher unexplained IIV in combination with lower RUV and IOV, exposure was best estimated by TDM, whereas, under lower unexplained IIV in combination with higher IOV or RUV, pharmacogenetic profiling was preferred. CONCLUSIONS: For the drugs with relatively low RUV and IOV (e.g., tamoxifen and tacrolimus), TDM estimated true exposure the best. Conversely, for drugs with similar or lower unexplained IIV (e.g., efavirenz or 5-FU, respectively) combined with relatively high RUV, pharmacogenetic profiling provided the most accurate estimate for most patients. However, genotype prevalence and the relative influence of genotypes on the PK, as well as the ability of TDM to accurately estimate AUC with a limited number of samples, had an impact. The results could be used to support clinical decision making when considering other factors, such as the probability for severe side effects.

Population Pharmacokinetics of Cabozantinib in Metastatic Renal Cell Carcinoma Patients: Towards Drug Expenses Saving Regimens.

INTRODUCTION: Cabozantinib is one of the preferred treatment options in the latest metastatic renal cell carcinoma (mRCC) guidelines. Cabozantinib is also associated with high drug expenses irrespective of the used dose, because a flat-prizing model has been implemented. In addition, concomitant intake with a high-fat meal increases its bioavailability on average by 57%. Combined with the long terminal half-life of cabozantinib (99 h), this creates possibilities to extend the dosing interval to reduce drug expenses whilst maintaining equivalent exposure. OBJECTIVES: The primary objective was to evaluate the population pharmacokinetic (POPPK) model of cabozantinib developed for its registration using real-world patients' therapeutic drug monitoring (TDM) data. The secondary objective was to design, simulate, and evaluate alternative dose regimens with the aim to reduce drug expenses whilst maintaining comparable exposure. METHODS: Retrospective TDM data from mRCC patients treated with cabozantinib were obtained. The data were evaluated using the published Food and Drug Administration (FDA) cabozantinib POPPK model, a two-compartment disposition model with a dual (fast and slow) lagged first-order absorption process derived from FDA registration documents, as a basis. Subsequently, simulations of alternative drug expenses saving regimens were evaluated. RESULTS: Twenty-seven mRCC patients with 75 pharmacokinetic observations were included. Patients were treated for a median of 75 days with a median dose of 40 mg. Model evaluation results showed that the cabozantinib TDM concentrations were adequately predicted by the published FDA cabozantinib POPPK model, except for a slightly higher clearance (CL) of 3.11 L/h compared to the reported value (2.23 L/h). The simulation study indicated that an alternative dose regimen that consists of taking 60 mg of cabozantinib for 2 days and then skipping 1 day results in comparable average exposure when compared with a 40 mg daily dose, both without food interaction, while saving 33.3% of the total drug expenses per month. The food effect of a high-fat meal was also taken into account when simulating other alternative dose regimens; 40 mg every 72 h combined with a high-fat meal resulted in comparable exposure when compared with a 20 mg daily dose fasted, while saving 66.7% in drug expenses. CONCLUSIONS: In this study, the optimized cabozantinib POPPK model resulted in adequate prediction of real-world cabozantinib pharmacokinetic data. Alternative dosing regimens with and without using known food interactions were proposed that resulted in potential strategies to significantly reduce cabozantinib drug expenses.

Dried blood spot sampling coupled with liquid chromatography-tandem mass for simultaneous quantitative analysis of multiple cardiovascular drugs.

Dried Blood Spots (DBS) revolutionize therapeutic drug monitoring using LC-MS for the precise quantification of cardiovascular drugs (CDs), enabling personalized treatment adapted to patient-specific pharmacokinetics with minimal invasiveness. This study aims to achieve simultaneous quantification of eight CDs in DBS, overcoming physicochemical challenges. A two-step protein precipitation method was used for simple and precise sample preparation. The drugs were analyzed using LC-MS/MS in ESI positive-ion mode, showing high sensitivity and linearity, with a correlation coefficient (r2) exceeding 0.999, after being separated on a reversed-phase chromatography by gradient elution of DW-acetonitrile containing 0.1 % formic acid + 2 mM ammonium formate. The validation results indicate good selectivity, with no observed matrix effect and carry-over. The intra- and inter-day accuracy and precision were within 6 % for most drugs, except for digoxin and deslanoside at low therapeutic levels where the variation was within 20 %. Stability tests confirmed suitable DBS handling and storage conditions, indicating drug stability for at least 30 days at room temperature. The analysis of whole spot has demonstrated remarkable precision and reliability in all target drugs. The analysis of 3 mm internal diameter discs, punched in and out of DBS, presumed to contain 3 µL of blood, showed acceptable accuracy for most drugs, with less polar drugs like digoxin and deslanoside showing lower accuracy, indicating a need for further correction due to non-uniform drug distribution. Consequently, the developed LC-MS/MS method enables the quantification of multiple CDs in a single DBS analysis, while suggesting the potential for accuracy-based analysis.

Quantification and analyses of seven tyrosine kinase inhibitors targeting hepatocellular carcinoma in human plasma by QuEChERS and UPLC-MS/MS.

Tyrosine kinase inhibitors (TKIs) are commonly used to treat various cancers. Literature suggests that the blood concentration of TKIs strongly correlates with their efficacy and adverse effects. Therefore, establishing a Therapeutic Drug Monitoring (TDM) methodology for TKI drugs is crucial to improving their clinical efficacy and minimizing the treatment-related adverse effects. However, quantifying their concentrations in the plasma using existing methods to avoid potential toxicity is challenging. Herein, seven TKIs, namely sorafenib tosylate, axitinib, erlotinib, cediranib, brivanib, linifanib, and golvatinib, were successfully analyzed in human plasma by following a quick, easy, cheap, effective, rugged, and safe (QuEChERS) pretreatment method combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Briefly, biological samples were extracted using 1 mL of methanol, followed by the sequential addition of 250 mg of anhydrous magnesium sulfate and 25 mg of N-propylethylenediamine (PSA) for salinization and purification by adsorption, respectively. In this study, dovitinib was used as the internal standard. The seven TKIs were detected by the gradient elution method for 4 min in the positive ion electrospray mode. The mobile phase comprised methanol (phase A) and 0.1 % aqueous formic acid solution (phase B) on the Agilent Zorbax RRHD Stablebond Aq, (2.1 × 50 mm; 1.8 µm). Brivanib, linifanib, axitinib, sorafenib tosylate, and golvatinib exhibited good linearity in the range of 5-500 ng/mL, and erlotinib and cediranib exhibited good linearity in the range of 10-1000 ng/mL, with linear correlation coefficients (R2) ≥ 0.99. The limits of detection and quantification were 0.60-0.18 ng/mL and 5-10 ng/mL, respectively. The intraday and interday accuracy values ranged from -6.12 % to 7.31 %, with a precision (RSD) of ≤ 10.57 %. The method was rapid, accurate, specific, simple, reproducible, and suitable for the quantitative determination of the seven TKIs in human plasma.