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Aims: Information on breastfeeding and safety of biologics in infants is lacking due to difficulties in case collection. We evaluated methods for determining the concentration of biologics in breast milk using a dry filter method that can simplify the collection, storage and transport of breast milk. Methods: To generate dried filter paper (DFP) samples, approximately 30 μL of breast milk was placed onto a Whatman 903 card and punched out. After extraction, the supernatant was measured using an enzyme‐linked immunosorbent assay. Three concentrations of each drug were prepared in liquid breast milk (LBM) and DFP samples to determine their stability up to 28 days after storage at 2–8°C or −20°C for LBM and 25 ± 5°C for DFP. LBM and DFP samples were also provided by nursing mothers using biologics during lactation, and drug concentrations in both samples were compared. The agreement between the two measurement methods was confirmed by Bland–Altman analysis. Results: Breast milk was provided by 12 mothers who used biologics (tocilizumab, abatacept, etanercept, golimumab, sarilumab and belimumab). The coefficients of variation for within‐run and between‐run precision for the six drugs were within 15% for both LBM and DFP, and accuracy was within 90%–110% of the quality controls. After 28 days, concentrations remained at more than 90%. The difference between the values obtained by each method was within the acceptable range of error (−12.1 to +16.6 ng/mL). Conclusions: A method for determining the concentration of biologics using DFP is expected to help improve pharmacotherapy for lactating women. [ABSTRACT FROM AUTHOR]

A recent article in the British Journal of Clinical Pharmacology discusses a method developed by Saito et al. to measure the concentrations of biologic agents in dried milk spots. The study provides insights into the pharmacokinetic properties of these agents and offers clinically important information for their safe use. However, the authors suggest that additional data on analyte stability in the filter paper and the integrity of the analytes extracted from breast milk are needed. They also question the conclusions drawn from the study and recommend further evaluation of the effects of variability in dried spots and the need for separate analysis for each drug. Overall, more validation and evaluation are required before applying this method in clinical trials or practice. [Extracted from the article]

Measurement of pre‐dose tacrolimus concentrations, also referred to as trough concentrations or C0 (in this paper the term C0 will be used), is the most frequently used parameter for therapeutic drug monitoring in patients after solid organ transplantation. C0 is relatively easy to obtain, and can be combined with other lab tests. C0 monitoring is convenient for patient and hospital staff. Adjusting the dose based on C0 assumes that the C0 has a good correlation with the overall exposure to the drug, as reflected in the area under concentration—time curve (AUC).However, C0 may not be the panacea it is suggested to be, and there are patients who may benefit from additional measurements to more precisely assess drug exposure. Especially in patients with a low C0/dose ratio, the peak tacrolimus concentrations after oral administration may be unexpectedly high, resulting in toxicity and (as has been shown already) in poor long‐term graft survival. At the other extreme, patients who only need a very low dose to reach target C0 may have a low peak and also a low AUC and may be underexposed.In this paper, the limitations of C0 will be discussed, and the type of studies needed to provide the evidence for implementation of more sophisticated therapeutic drug monitoring. The paper focuses on treatment of adult kidney transplant recipients. [ABSTRACT FROM AUTHOR]

Opioid use disorder (OUD) and chronic pain are commonly co‐occurring disorders which can exacerbate each other. Sex/gender differences have been shown in aspects of the clinical course and biological underpinnings of both OUD and chronic pain. The purpose of this scoping review is to summarize literature which has addressed sex/gender differences in relation to the confluence of OUD and chronic pain. This review focused on peer‐reviewed journal articles with human subjects and addressing (a) opioid misuse, chronic opioid use or opioid use disorder (OUD), (b) chronic or persistent pain and (c) sex/gender differences in relation to OUD and/or chronic pain. Of the 146 papers identified by the search strategy, 30 met the criteria for inclusion. Charting focused on a priori themes of chronic pain, opioid misuse/OUD and sex/gender in sample, predictor and outcome variables, and key study findings. The majority of research identified was cross‐sectional in nature, and sex/gender differences and treatment effects were largely included as post‐hoc analyses. Together, the results of this early work align with higher prevalence for OUD in men/males and chronic pain in women/females, while adding critical information with respect to potential sex/gender differences in the development and treatment of their co‐occurrence across a range of biological and psychosocial factors. Findings underline the importance of considering sex and gender in the intersection of the development and treatment of OUD and chronic pain. [ABSTRACT FROM AUTHOR]

Aims Methods Results Conclusions Previous systematic reviews suggest that deprescribing may improve survival, particularly in frail older people. Evidence is rapidly accumulating, suggesting a need for an updated review of the literature.We updated a 2016 systematic review and meta‐analysis to include studies published from inception to 26 April 2024 from specified databases. Studies in which older people had at least one medication deprescribed were included and grouped by study designs and targeted medications. The risk of bias was assessed using the Cochrane tool and the Newcastle‐Ottawa tool. Odds ratios (OR) or mean differences were calculated as the effect measures using either the Mantel–Haenszel or generic inverse‐variance method with fixed‐ or random‐effects meta‐analyses. The primary outcome was mortality. Secondary outcomes were adverse drug withdrawal events, physical health, cognitive function, quality of life and effect on medication regimen. Subgroup analyses were performed based on age and intervention types.A total of 259 studies (reported in 286 papers) were included in this updated review. Deprescribing polypharmacy did not result in a significant reduction in mortality in both randomized (OR 0.96, 95% confidence interval [CI] 0.84–1.09) and non‐randomized studies (OR 0.70, 95% CI 0.36–1.38). Further subgroup analyses of randomized studies on deprescribing polypharmacy demonstrated a significant reduction in mortality in the young old (aged 65–79) (OR 0.71, 95% CI 0.51–0.99) and when patient‐specific interventions were applied (OR 0.79, 95% CI 0.63–0.99).Deprescribing can be achieved with potentially important benefits in terms of improved survival, particularly when patient‐specific interventions are applied and initiated early in the young old. [ABSTRACT FROM AUTHOR]

In solid organ transplantation (SOT), biologicals such as recombinant therapeutic proteins, monoclonal antibodies, fusion proteins and conjugates are increasingly used for immunosuppression, desensitization, ABO (blood group) incompatibility, antibody‐mediated rejections and atypical haemolytic uremic syndrome. In this paper, we review the medical evidence available for biologicals used in SOT and the potential for improvement by the application of therapeutic drug monitoring (TDM) and model‐informed precision dosing. Biologicals are used for off‐label indications within the field of SOT, building on the experience from their use on labelled indications. Dosing is currently mostly standard, and experience vs. effect and toxicity is limited. Pharmacokinetic characteristics of these large, partly also immunogenic molecules differ from those of traditional small molecules. Individualization by concentration measurements and modelling has mostly been proof‐of‐concept or feasibility studies that lack the power to provide evidence for improvement in clinical outcome. For some drugs such as alemtuzumab, eculizumab, rituximab, tocilizumab and belatacept, studies have demonstrated significant interindividual variability in pharmacokinetics. Variability in absorption from subcutaneous administration may increase interindividual variability. There is also an economic aspect of appropriate dosing that needs to be pursued. Available assays and models to refine interpretation are in place, but trials of adequate size to document the usefulness of TDM and MIPD are scarce. Collaboration within the TDM community seems mandatory to establish studies of sufficient strength to provide evidence for the use of biologicals that are currently used off‐label in SOT and furthermore to identify the settings where TDM may be beneficial. [ABSTRACT FROM AUTHOR]

Aims: The global older population is growing rapidly, and the rise in polypharmacy has increased potentially inappropriate medication (PIM) encounters. PIMs pose health risks, but detecting them automatically in large medical databases is complex. This review aimed to uncover PIM prevalence in individuals aged 65 years or older using health databases and emphasized the risk of underestimating PIM prevalence due to underutilization of detection tools. Methods: This study conducted a broad search on the Medline database to identify articles about the prevalence of PIMs in older adults using various databases. Articles published between January 2010 and June 2023 were included, and specific criteria were applied for study selection. Two literature reviews conducted before our study period were integrated to obtain a perspective from the 1990s to the present day. The selected papers were analysed for variables including database type, screening method, adaptations and PIM prevalence. The study categorized databases and original screening tools for clarity, examined adaptations and assessed concordance among different screening methods. Results: This study encompassed 48 manuscripts, covering 58 sample evaluations. The mean prevalence of PIMs within the general population aged over 65 years was 27.8%. Relevant heterogeneity emerged in both the utilized databases and the detection methods. Adaptation of original screening tools was observed in 86.2% (50/58) of cases. Half of the original screening tools used for assessing PIMs belonged to the simple category. About a third of the studies employed less than half of the original criteria after adaptation. Only three studies used over 75% of the original criteria and more than 50 criteria. Conclusions: This extensive review highlights PIM prevalence among the older adults, emphasizing method intricacies and the potential for underestimation due to data limitations and algorithm adjustments. The findings call for enhanced methodologies, transparent algorithms and a deeper understanding of intricate rules' impact on public health implications. [ABSTRACT FROM AUTHOR]

Cytomegalovirus (CMV) infection frequently occurs after solid organ transplantation and is associated with an increased morbidity and mortality. Fortunately, the development of valganciclovir prophylaxis has lowered the incidence of CMV infection and its complications in immunosuppressed solid organ transplant recipients. However, breakthrough infections during valganciclovir prophylaxis and late CMV infection after cessation of valganciclovir prophylaxis still occur with the current prophylactic strategy. Additionally, valganciclovir resistance has emerged among CMV strains, which complicates the treatment of CMV infections. Furthermore, the use of valganciclovir is associated with myelotoxicity, which can lead to the premature withdrawal of prophylaxis. It is important to address these current issues in order to improve the standard care after solid organ transplantation. This paper will therefore discuss the clinical practice of valganciclovir prophylaxis, elaborate on its issues and suggest how to improve the current prophylactic strategy with a possible role for therapeutic drug monitoring. [ABSTRACT FROM AUTHOR]

The British Journal of Clinical Pharmacology highlights several papers in its latest issue. One paper discusses the updated EMA guideline on medicinal products containing genetically modified cells. Two other papers focus on adherence, with one reporting that research underestimates non-adherence and the other suggesting that patient-reported daily doses can improve estimates of adherence. The issue also includes a study on the use of artificial intelligence in pharmacovigilance and a report on high-fidelity simulation medical education training in acute clinical toxicology. Lastly, a study from South Africa examines determinants of early changes in serum creatinine in individuals starting antiretroviral therapy for HIV. [Extracted from the article]

Aims Methods Results Conclusion In this reflection paper, the authors, based on their experience as teachers and students of the courses of Pharmacology at the University of Bologna, reflect on their specific roles towards innovation in the teaching of Clinical Pharmacology.Strengths, weaknesses and challenges are presented as identified during the teaching and learning experience in the currently evolving medical degree programmes of the University in light of current trends in medical education.Keeping in mind the identified challenges together with the features proposed for the model prescriber (knowledgeable, contemporary, communicative and safe), we indicate some ways to improve the students' experience and make sure they develop up‐to‐date skills in Clinical Pharmacology taking advantage of recent ongoing collaborations at European level. International collaboration is indeed necessary to adequately address the current challenges of teaching clinical pharmacology.Our shared conclusion is that empowering students with a scientifically sound method to retrieve relevant information and developing their skills to communicate in an interprofessional and, wherever possible, international environment is the key to prepare future prescribers and, ultimately, to improve patient safety. [ABSTRACT FROM AUTHOR]

This paper aims to explore the possibility of employing large language models (LLMs) – a type of artificial intelligence (AI) – in clinical pharmacology, with a focus on its possible misuse in bioweapon development. Additionally, ethical considerations, legislation and potential risk reduction measures are analysed. The existing literature is reviewed to investigate the potential misuse of AI and LLMs in bioweapon creation. The search includes articles from PubMed, Scopus and Web of Science Core Collection that were identified using a specific protocol. To explore the regulatory landscape, the OECD.ai platform was used. The review highlights the dual‐use vulnerability of AI and LLMs, with a focus on bioweapon development. Subsequently, a case study is used to illustrate the potential of AI manipulation resulting in harmful substance synthesis. Existing regulations inadequately address the ethical concerns tied to AI and LLMs. Mitigation measures are proposed, including technical solutions (explainable AI), establishing ethical guidelines through collaborative efforts, and implementing policy changes to create a comprehensive regulatory framework. The integration of AI and LLMs into clinical pharmacology presents invaluable opportunities, while also introducing significant ethical and safety considerations. Addressing the dual‐use nature of AI requires robust regulations, as well as adopting a strategic approach grounded in technical solutions and ethical values following the principles of transparency, accountability and safety. Additionally, AI's potential role in developing countermeasures against novel hazardous substances is underscored. By adopting a proactive approach, the potential benefits of AI and LLMs can be fully harnessed while minimizing the associated risks. [ABSTRACT FROM AUTHOR]

Aims: A key reason for the failure of antituberculosis (anti‐TB) treatment is missed doses (instances where medication is not taken). Adverse drug reactions (ADRs) are 1 cause of missed doses, but the global evidence, their relative contribution to missed doses vs. other causes, the patterns of missed doses due to ADRs and the specific ADRs associated with missed doses have not been appraised. We sought to address these questions through a scoping review. Methods: MEDLINE, Embase and Web of Science were searched on 3 November 2021 using terms around active TB, missed doses and treatment challenges. Studies reporting both ADR and missed dose data were examined (PROSPERO: CRD42022295209). Results: Searches identified 108 eligible studies: 88/108 (81%) studies associated ADRs with an increase in missed doses; 33/61 (54%) studies documenting the reasons for missed doses gave ADRs as a primary reason. No studies examined patterns of missed doses due to ADRs; 41/108 (38%) studies examined associations between 68 types of ADR (across 15 organ systems) and missed doses. Nuance around ADR‐missed doses relations regarding drug susceptibility testing profile and whether the missed doses originated from the patient, healthcare professionals, or both were found. Conclusion: There is extensive evidence that ADRs are a key driver for missed doses of anti‐TB treatment. Some papers examined specific ADRs and none evaluated the patterns of missed doses due to ADRs, demonstrating a knowledge deficit. Knowing why doses both are and are not missed is essential in providing targeted interventions to improve treatment outcomes. [ABSTRACT FROM AUTHOR]

The British Journal of Clinical Pharmacology's March issue highlights the incorporation of Artificial Intelligence (AI) into clinical pharmacology research, education, patient care, drug development, and dissemination. The issue also features papers on the side effects of drugs, including sex differences in serious adverse drug reactions, predicting adverse drug reactions in neonates, and a program for reporting adverse drug reactions in children and young adults. Additionally, the issue discusses inappropriate prescribing, standardization in pharmacovigilance efforts for pregnancy and breastfeeding, and the effects of isotretinoin on metabolizing enzymes. The author encourages readers to explore the editorial and all the papers on AI and clinical pharmacology. [Extracted from the article]

The British Journal of Clinical Pharmacology's February issue highlights several research papers on various topics. One study focuses on a potential treatment for autoimmune diseases using a novel C‐X‐C chemokine receptor 3 antagonist. Another paper examines the absorption, distribution, metabolism, and elimination of a cholesterol 24‐hydroxylase inhibitor for the treatment of seizures. Additionally, the issue includes critical evaluations of evidence from clinical studies, such as the use of oral gonadotrophin releasing hormone antagonists for uterine fibroids and the establishment of a children's Drugs and Therapeutics Committee. The issue also discusses the United Kingdom Prescribing Safety Assessment, which assesses the competence of physicians to prescribe medications. Overall, this issue offers valuable insights for clinical pharmacologists. [Extracted from the article]

The British Journal of Clinical Pharmacology's latest issue highlights include a Themed Issue on Drug Safety, which emphasizes the importance of investigating and limiting side effects while maintaining efficacy. The journal also features two papers on adherence, discussing the potential use of model-based TDM for optimizing antihypertensive drugs and the adverse consequences of undiagnosed nonadherence in Randomized Controlled Trials. The author concludes by wishing readers a safe and enjoyable summer. [Extracted from the article]

The British Journal of Clinical Pharmacology has published its June issue, which includes a range of articles on various topics. One article discusses the development of a method for extracting information on drug-health food product interactions using language processing techniques. Another article explores the risk/benefit ratio of different medications, such as potentially inappropriate medications for newly treated patients with type 2 diabetes and the risk of delirium after sedation with propofol or midazolam in intensive care units. Additionally, the issue features papers on ADME and pharmacokinetics. Readers can access the full articles through the provided links. [Extracted from the article]

The article titled "The association between proton pump inhibitor use and systemic anti-tumour therapy on survival outcomes in patients with advanced non-small cell lung cancer: A systematic review and meta-analysis" by Na Wei, Bin Zheng, Wancai Que, Jin Zhang, and Maobai Liu has issued a correction regarding the use of "Begger's test" in the statistical analysis and publication bias sections. The correct term should be "Begg's test." The authors assure readers that these corrections do not significantly affect the overall findings and conclusions of the paper. They apologize for any confusion caused and appreciate the opportunity to rectify the errors. [Extracted from the article]

Aim: Understanding how COVID-19 impacts the expression of clinically relevant drug metabolizing enzymes and membrane transporters (DMETs) is vital for addressing potential safety and efficacy concerns related to systemic and peripheral drug concentrations. This study investigates the impact of COVID-19 severity on DMETs expression and the underlying mechanisms to inform the design of precise clinical dosing regimens for affected patients., Methods: Transcriptomics analysis of 102 DMETs, 10 inflammatory markers, and 12 xenosensing regulatory genes was conducted on nasopharyngeal swabs from 50 SARS-CoV-2 positive (17 outpatients, 16 non-ICU, and 17 ICU) and 13 SARS-CoV-2 negative individuals, clinically tested through qPCR, in the Greater Toronto area from October 2020 to October 2021., Results: We observed a significant differential gene expression for 42 DMETs, 6 inflammatory markers, and 9 xenosensing regulatory genes. COVID-19 severity was associated with the upregulation of AKR1C1, MGST1, and SULT1E1, and downregulation of ABCC10, CYP3A43, and SLC29A4 expressions. Altogether, SARS-CoV-2-positive patients showed an upregulation in CYP2C9, CYP2C19, AKR1C1, SULT1B1, SULT2B1, and SLCO4A1 and downregulation in FMO5, MGST3, ABCC5, and SLCO4C1 compared with SARS-CoV-2 negative individuals. These dysregulations were associated with significant changes in the expression of inflammatory and xenosensing regulatory genes driven by the disease. GSTM3, PPARA, and AKR1C1 are potential biomarkers of the observed DMETs dysregulation pattern in nasopharyngeal swabs of outpatients, non-ICU, and ICU patients, respectively., Conclusion: The severity of COVID-19 is associated with the dysregulation of DMETs involved in processing commonly prescribed drugs, suggesting potential disease-drug interactions, especially for narrow therapeutic index drugs., (© 2024 The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: Population pharmacokinetics (PK) models may be effective in improving antibiotic exposure with individualized dosing. The aim of the study is to assess cefazolin exposure using a population PK model in critically ill children., Methods: We conducted a single-centre observational study including children under 18 years old who had cefazolin plasma monitoring before and after a cefazolin model implementation. The first concentration at steady state of each cefazolin course was analysed. The optimal exposure was defined by concentration values ranging from free concentration over four times the minimal inhibitory concentration (MIC) for 100% of the dosing interval to total trough or plateau concentration under 100 mg. L -1 ., Results: A total of 58 patients were included, of whom 39 and 19 children received conventional dosing or model-informed dosing, respectively. Median [range] age was 2.3 [0.1-17] years old, and median weight was 14.2 [2.9-72] kg. There were more continuous infusions (CI) in the model group than in the conventional group (n = 19/19 [100%] vs. n = 23/39 [59%]). Compared to conventional dosing, model-informed dosing provided more optimal exposure (n = 17/39 [44%] vs. n = 15/19 [79%], P = .01) and less underexposure (n = 18/39 [46%] vs. n = 2/19 [10%], P = .008), without increasing overexposure (n = 4/39 [10%] vs. n = 2/19 [11%], P = 1). Moreover, the time to C-reactive protein decrease by 50% was significantly shorter in the model group than the conventional group (3 [0.5-13] vs. 4 [1-34]; P = .045)., Conclusions: Use of individualized cefazolin model-informed dosing improves critically ill children's exposure. Further studies are needed to assess the clinical benefit of cefazolin PK model application., (© 2024 British Pharmacological Society.)

Older adults are at risk of adverse drug events during transition of care from hospital to community, thus optimal communication about medications at discharge is essential. Standardization of medication discharge plan (MDP) is lacking. This study aimed to (1) create a standardized MDP for older adults using consensus-based principles, (2) create a short-version MDP and (3) generate a practical guide. Modified Delphi was used to establish consensus on guiding principles for the MDP. Additionally, participants were asked about guiding principles deemed most essential, patient prioritization, the format and mode of transmission of the MDP. Twenty-six guiding principles reached consensus, with 17 prioritized for a short-version MDP. The practical guide includes explanations of the guiding principles, criteria for patient selection and recommendations on the format and mode of transmission. The results of this study will assist implementation of MDPs when older adults are discharged from hospital., (© 2024 The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: To investigate plasma apixaban concentrations and thrombin generation assay (TGA) parameters across different apixaban doses in atrial fibrillation patients who had dose-reduction criteria for apixaban., Methods: This observational study included 374 patients (mean age 75.6 ± 7.7 years, 54.8% female) with dose-reduction criteria for apixaban. The patients were divided into 3 groups: (i) on-label standard dose (5 mg twice daily, n = 166); (ii) on-label reduced dose (2.5 mg twice daily, n = 55); and (iii) off-label underdose (2.5 mg twice daily, n = 153). Apixaban concentrations determined via the anti-Xa assay and TGA parameters were compared at trough levels., Results: The off-label underdose group exhibited significantly lower apixaban trough concentrations than the on-label reduced-dose and standard-dose groups (56.7 ± 42.9 vs. 83.7 ± 70.4 vs. 129.9 ± 101.8 ng/mL, all P < .001). Less than 70% of all patients fell within the expected range of apixaban concentrations. Proportions exceeding the upper limit of the expected range were significantly lower in the off-label underdose group (1.3%) than in the on-label reduced-dose (9.1%, P = .005) and standard-dose (12.7%, P < .001) groups. The TGA parameters showed the on-label standard-dose group displaying the lowest thrombogenic profiles. Lower creatinine clearance was the most significant predictor of higher apixaban concentrations., Conclusion: Off-label underdosed apixaban resulted in lower apixaban concentrations than both on-label standard and reduced-dose regimens. A considerable proportion of the patients exhibited apixaban concentrations outside the expected range, suggesting the potential benefits of plasma concentration monitoring. Further studies are needed to compare dosages directly, investigate the impact of plasma apixaban concentration monitoring and validate the current dose-reduction criteria., (© 2024 British Pharmacological Society.)

In this systematic review, we report on the effects of diuretic deprescribing compared to continued diuretic use. We included clinical studies reporting on outcomes such as mortality, heart failure recurrence, tolerability and feasibility. We assessed risk of bias and certainty of the evidence using the GRADE framework. We included 25 publications from 22 primary studies (15 randomized controlled trials; 7 nonrandomized studies). The mean number of participants in the deprescribing groups was 35, and median/mean age 64 years. In patients with heart failure, there was no clear evidence that diuretic deprescribing was associated with increased mortality compared to diuretic continuation (low certainty evidence). The risk of cardiovascular composite outcomes associated with diuretic deprescribing was inconsistent (studies showing lower risk for diuretic deprescribing, or comparable risk with diuretic continuation; very low certainty evidence). The effect on heart failure recurrence after diuretic deprescribing in patients with diuretics for heart failure, and of hypertension in patients with diuretics for hypertension was inconsistent across the included studies (low certainty evidence). In patients with diuretics for hypertension, diuretic deprescribing was well tolerated (moderate certainty evidence), while in patients with diuretics for heart failure, deprescribing diuretics can result in complaints of peripheral oedema (very low certainty evidence). The overall risk of bias was generally high. In summary, this systematic review suggests that diuretic discontinuation could be a safe and feasible treatment option for carefully selected patients. However, there isa lack of high-quality evidence on its feasibility, safety and tolerability of diuretic deprescribing, warranting further research., (© 2024 The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: We report on investigations exploring the P2X3-receptor antagonist filapixant's effect on taste perception and cough-reflex sensitivity and describe its pharmacokinetics, including its CYP3A4-interaction potential., Methods: In a randomized, placebo-controlled, double-blind study, 3 × 12 healthy men (18-45 years) were assigned (3:1) to filapixant (20, 80 or 250 mg by mouth) or placebo twice daily over 2 weeks. A single dose of midazolam (1 mg), a CYP3A4 substrate, was administered with and without filapixant. Assessments included a taste-strips test, a taste questionnaire, cough challenge with adenosine triphosphate, adverse event reports and standard safety assessments., Results: Taste disturbances were observed mainly in the 250-mg group: six of nine participants (67%) in this group reported hypo- or dysgeusia in the questionnaire; eight participants (89%) reported taste-related adverse events. Five participants (56%) had a decrease in overall taste-strips-test scores ≥2 points (point estimate -1.1 points, 90% confidence interval [-3.3; 1.1]). Cough counts increased with adenosine triphosphate concentration but without major differences between treatments. Filapixant exposure increased proportionally to dose. Co-administration of filapixant had no clinically relevant effect on midazolam pharmacokinetics. Area under the concentration-time curve ratios and 90% confidence intervals were within 80-125%. No serious or severe adverse events were reported., Conclusions: Overall, filapixant was safe and well tolerated, apart from mild, transient taste disturbances. Such disturbances occurred more frequently than expected based on (in vitro) receptor-selectivity data, suggesting that other factors than P2X3:P2X2/3 selectivity might also play an important role in this context. The cough-challenge test showed no clear treatment effect. Filapixant has no clinically relevant CYP3A4 interaction potential., (© 2024 Bayer AG and The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Drug hypersensitivity reactions (DHRs) are type B adverse drug reactions (ADRs) traditionally defined as unpredictable, dose independent and not related to the drug pharmacology. DHRs, also called drug allergy if the immune system involvement is confirmed, represent around one-sixth of all ADRs and can cause major clinical problems due to their vague clinical presentation and irregular time course. Understanding the underlying pathophysiology of DHRs is very important for their diagnosis and management. Multiple layers of evidence exist pointing to the involvement of the immune system in DHRs. Recent data have led to a paradigm shift in our understanding of the exact pathophysiology of these reactions. Numerous hypotheses proposing explanation on how a low molecular weight drug molecule can elicit an immune reaction have been proposed. In addition to the classical "hapten" hypothesis, the reactive metabolite hypothesis, the pharmacological interaction with the immune system (p-i) concept, the danger/injury hypothesis and the altered peptide repertoire hypothesis have been proposed. We here introduce the inflammasome activation hypothesis and the cross-reactivity hypothesis as additional models explaining the pathophysiology of DHRs. Available data supporting these hypotheses are briefly summarized and discussed. We also introduced the cross-reactivity model, which may provide a platform to appreciate the potential role played by other factors leading to the activation of the immune system. We believe that although the drug in question could be the trigger of the reaction, the components of the immune system mediating the reaction do not act in isolation but rather are affected by the proinflammatory milieu occurring at the time of the reaction. This review attempts to summarize the available evidence to further illustrate the pathophysiology of DHRs., (© 2022 British Pharmacological Society.)

Drug-induced skin disease or cutaneous adverse drug reactions (CADRs) are terms that encompass the clinical manifestations of the skin, mucosae and adnexa induced by a drug or its metabolites. The skin is the organ most frequently affected by drug reactions, which may affect up to 10% of hospitalized patients and occur in 1-3% of multimedicated patients. Most CADRs are mild or self-resolving conditions; however, 2-6.7% of could develop into potentially life-threatening conditions. CADRs represent a heterogeneous field and can be diagnostically challenging as they may potentially mimic any dermatosis. Currently, there are between 29-35 different cutaneous drug-reaction patterns reported ranging from mild dermatitis to an extensively burnt patient. The most frequently reported are maculopapular rash, urticaria/angioedema, fixed drug eruption and erythema multiforme. Less common but more severe patterns include erythroderma, drug reaction with eosinophilia and systemic symptoms, and Stevens-Johnson syndrome/toxic epidermal necrolysis spectrum. Almost any drug can induce a CADR, but antibiotics, nonsteroidal anti-inflammatory drugs and antiepileptics are the most frequently involved. Different mechanisms are involved in the pathogenesis of CADRs, although in some cases, these remain still unknown. CADRs could be classified in different ways: (i) type A (augmented) or type B (bizarre); (ii) immediate or delayed; (iii) immune-mediated or nonimmune-mediated; (iv) nonsevere or life-threatening; and (v) by their phenotype, including exanthematous, urticarial, pustular and blistering morphology. Recognizing a specific CADR will mostly depend on the ability of the physician to perform a detailed clinical examination, the proper description of the morphology of the skin lesions and supporting laboratory and/or skin biopsy findings., (© 2022 British Pharmacological Society.)

Patients are often switched between generic formulations of the same drug, but in some cases generic interchangeability is questioned. For generic drugs to be approved, bioequivalence with the innovator drug should be demonstrated, but evidence of bioequivalence is not required in the intended patient population or relative to other approved generics., Aim: We aim to identify pathophysiological pharmacokinetic subpopulations for whom there is a difference in comparative bioavailability compared to a healthy population., Methods: We used simulated exposures from a nonparametric model of multiple generics and the originator gabapentin. Exposure was simulated for virtual populations with pharmacokinetic characteristics beyond those of healthy subjects with regard to rate of absorption, volume of distribution and reduced renal function. Virtual parallel design bioequivalence studies were performed using a random sample of 24 simulated subjects, with standard acceptance criteria., Results: Results indicated increased pharmacokinetic variability for patient populations with a lower rate of absorption or a reduced renal function, but no change in the average comparable bioavailability ratio. This increased variability results in a reduced likelihood of demonstrating bioequivalence. Observations were similar for comparisons between all different formulations, as well as between subjects who received the identical formulation in a repeated fashion. No relevant effect was observed for simulations with increased volume of distribution., Conclusion: Our simulations indicate that the reduced likelihood of demonstrating bioequivalence for subjects with altered pharmacokinetics is not influenced by a formulation switch, nor does the average comparable bioavailability ratio change, therefore these results support generic interchangeability and current approval requirements for generics., (© 2022 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: While diagnostic codes from administrative health data might be a valuable source to identify adverse drug events (ADEs), their ability to identify unintended harms remains unclear. We validated claims-based diagnosis codes for ADEs based on events identified in a prospective cohort study and assessed whether key attributes predicted their documentation in administrative data., Methods: This was a retrospective analysis of 3 prospective cohorts in British Columbia, from 2008 to 2015 (n = 13 969). We linked prospectively identified ADEs to administrative insurance data to examine the sensitivity and specificity of different diagnostic code schemes. We used logistic regression to assess which key attributes (e.g., type of event, symptoms and culprit medications) were associated with better documentation of ADEs in administrative data., Results: Among 1178 diagnosed events, the sensitivity of the diagnostic codes in administrative data ranged from 3.4 to 52.6%, depending on the database and codes used. We found that documentation was worse for certain types of ADEs (dose-related: odds ratio [OR]: 0.32, 95% confidence interval [CI]: 0.15, 0.69; nonadherence events (OR: 0.35, 95% CI: 0.20, 0.62), and better for those experiencing arrhythmias (OR: 4.19, 95% CI: 0.96, 18.28)., Conclusion: ADEs were not well documented in administrative data. Alternative methods should be explored to capture ADEs for health research., (© 2024 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: Meropenem/vaborbactam combination is approved in adults by FDA and EMA for complicated urinary tract infections and by EMA also for other Gram-negative infections. We aimed to characterise the pharmacokinetics of both moieties in an ongoing study in children and use a model-based approach to inform adequate dosing regimens in paediatric patients., Methods: Over 4196 blood samples of meropenem and vaborbactam (n = 414 subjects) in adults, together with 114 blood samples (n = 39) in paediatric patients aged 3 months to 18 years were available for this analysis. Data were analysed using a population with prior information from a pharmacokinetic model in adults to inform parameter estimation in children. Simulations were performed to assess the suitability of different dosing regimens to achieve adequate probability of target attainment (PTA)., Results: Meropenem/vaborbactam PK was described with two-compartment models with first-order elimination. Body weight and CLcr were significant covariates on the disposition of both drugs. A maturation function was evaluated to explore changes in clearance in neonates. PTA ≥90% was derived for children aged ≥3 months after 3.5-h IV infusion of 40 mg/kg Q8h of both meropenem and vaborbactam and 2 g/2 g for those ≥50 kg. Extrapolation of disposition parameters suggest that adequate PTA is achieved after a 3.5-h IV infusion of 20 mg/kg for neonates and infants (3 months)., Conclusions: An integrated analysis of adult and paediatric data allowed accurate description of sparsely sampled meropenem/vaborbactam PK in paediatric patients and provided recommendations for the dosing in neonates and infants (3 months)., (© 2024 British Pharmacological Society.)

Aims: To evaluate relationships between plasma concentrations of belantamab mafodotin, total monoclonal antibody, and its payload and changes in electrocardiogram (ECG) parameters in patients with relapsed or refractory multiple myeloma from the DREAMM-1 and DREAMM-2 studies., Methods: Hysteresis plots and linear regression analyses of pharmacokinetic (PK) analyte (belantamab mafodotin, total monoclonal antibody, and cytotoxic cysteine-maleimidocaproyl monomethyl auristatin F payload) concentrations vs. time-matched ECG parameters (absolute/change from baseline in QT interval corrected for RR interval [QTc/ΔQTc] and QT interval corrected for heart rate by Fridericia's formula [QTcF/ΔQTcF]) were performed. Concentrations of PK analyte required for a 10-ms increase in QTc in DREAMM-2 were calculated via simulation, as was the probability of ΔQTc/ΔQTcF exceeding 10 ms for the expected C max of PK analyte concentrations associated with the doses (2.5 and 3.4 mg/kg) administered in DREAMM-2., Results: Time-matched PK and ECG data from 290 patients (DREAMM-1, n = 73; DREAMM-2, n = 217) were analysed. Hysteresis plots did not clearly indicate any concentration-related prolongation in QTc or QTcF; regression analyses indicated a very small rate of increase in ΔQTc and ΔQTcF with increasing concentrations of PK analytes. Calculated concentrations of PK analyte required for a 10-ms prolongation in QTc were higher than the maximum analyte concentrations observed following treatment with belantamab mafodotin in DREAMM-2; the probability that each dose would prolong ΔQTc and ΔQTcF by >10 ms was 0 and <0.25%, respectively., Conclusion: This study of belantamab mafodotin and its payload did not provide evidence of QT prolongation in patients with relapsed or refractory multiple myeloma at clinically relevant doses., (© 2024 GSK Plc. and The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: The aim of this study was to estimate the prevalence of potentially inappropriate prescriptions (PIPs) in patients starting their first noninsulin antidiabetic treatment (NIAD) using two explicit process measures of the appropriateness of prescribing in UK primary care, stratified by age and polypharmacy status., Methods: A descriptive cohort study between 2016 and 2019 was conducted to assess PIPs in patients aged ≥45 years at the start of their first NIAD, stratified by age and polypharmacy status. The American Geriatrics Society Beers criteria 2015 was used for older (≥65 years) patients and the Prescribing Optimally in Middle-age People's Treatments criteria was used for middle-aged (45-64 years) patients. Prevalence of overall PIPs and individual PIPs criteria was reported using the IQVIA Medical Research Data incorporating THIN, a Cegedim Database of anonymized electronic health records in the UK., Results: Among 28 604 patients initiating NIADs, 18 494 (64.7%) received polypharmacy. In older and middle-aged patients with polypharmacy, 39.6% and 22.7%, respectively, received ≥1 PIP. At the individual PIP level, long-term proton pump inhibitors (PPI) use was the most frequent PIP among older adults, and strong opioid without laxatives was the most frequent PIP in middle-aged patients with polypharmacy (11.1% and 4.1%, respectively)., Conclusions: This study revealed that patients starting NIAD treatment receiving polypharmacy have the potential for pharmacotherapy optimization., (© 2024 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: The aim of this study was to estimate adherence to urate-lowering therapy (ULT), predominately allopurinol, from Australia's Pharmaceutical Benefits Scheme (PBS) claims database in association with (1) patient-reported doses and (2) World Health Organization's (WHO) defined daily doses (DDD), namely, allopurinol (400 mg/day) or febuxostat (80 mg/day)., Methods: Proportion of days covered (PDC) was calculated in 108 Gout App (Gout APP) trial participants with at least two recorded ULT dispensings in an approximately 12-month period before provision of intervention or control apps. Adherence was defined as PDC ≥80%. We measured the correlation between the two methods of calculating PDC using a Wilcoxon signed rank test. Agreement between ULT-taking status (self-reports) and ULT-dispensed status (PBS records) was tested with Cohen's kappa (κ), and positive and negative percent agreement., Results: Allopurinol was prescribed in 93.5% of participants taking ULT. Their self-reported mean daily dose (SD) was 291 (167) mg/day. Mean PDC (SD) for allopurinol was 83% (21%) calculated using self-reported dose, and 63% (24%) using WHO's DDD. Sixty-three percent of allopurinol users were identified as adherent (PDC ≥80%) using self-reported dose. There was good agreement between self-reported ULT use and PBS dispensing claims (κ = 0.708, P < .001; positive percent agreement = 90%, negative percent agreement = 82%)., Conclusions: Participant-reported allopurinol daily doses, in addition to PBS dispensing claims, may enhance confidence in estimating PDC and adherence compared to using DDD. This approach improves adherence estimations from pharmaceutical claims datasets for medications where daily doses vary between individuals or where there is a wide therapeutic dose range., (© 2024 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Great advances have been made in the knowledge of development and regulatory approval of medicinal product containing genetically modified cells. Although a guideline has been available in the EU since 2012, the current updated version provides a useful guide to developers and professionals involved in the regulatory process of these medicines. This article presents the main issues communicated in that guidance, the regulators' insights and a commentary from the academic developers' point of view., (© 2024 British Pharmacological Society.)

Aims: Many transgender and gender diverse (TGD) individuals have expressed concerns about the potential for oral pre-exposure prophylaxis to affect hormonal concentrations achieved from taking gender-affirming hormone therapy (GAHT). The purpose of this study was to understand the bidirectional effects between hormone and intraerythrocytic tenofovir diphosphate concentrations when switching from tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) to tenofovir alafenamide/emtricitabine (TAF/FTC) in TGD users/nonusers of GAHT., Methods: The study evaluated stored blood samples and dried blood spot cards from TGD adults without HIV who took ≥12 weeks of TDF/FTC and then switched to ≥12 weeks of TAF/FTC for pre-exposure prophylaxis., Results: Thirty-nine individuals met the study inclusion criteria. Regardless of sex assigned at birth and the use of GAHT, there were no significant differences in hormone concentrations when individuals taking GAHT were taking TDF/FTC and then switched to TAF/FTC. Further, there was no significant difference in intraerythrocytic tenofovir diphosphate concentrations between users and nonusers of GAHT., Conclusion: There are no bidirectional effects between hormone and intraerythocytic tenofovir diphosphate concentrations when switching from TDF/FTC to TAF/FTC in TGD users/nonusers of GAHT., (© 2024 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: Amikacin requires therapeutic drug monitoring for optimum efficacy; however, the optimal model-informed precision dosing strategy for the area under the concentration-time curve (AUC) of amikacin is uncertain. This simulation study aimed to determine the efficient blood sampling points using the Bayesian forecasting approach for early achievement of the target AUC range for amikacin in critically ill patients., Methods: We generated a virtual population of 3000 individuals using 2 validated population pharmacokinetic models identified using a systematic literature search. AUC for each blood sampling point was evaluated using the probability of achieving a ratio of estimated/reference AUC at steady state in the 0.8-1.2 range., Results: On day 1, the 1-point samplings for population pharmacokinetic models showed a priori probabilities of 26.3 and 45.6%, which increased to 47.3 and 94.4% at 23 and 15 h, respectively. Using 2-point sampling at the peak (3 and 4 h) and trough (24 h) on day 1, these probabilities further increased to 72.3 and 99.5%, respectively. These probabilities were comparable on days 2 and 3, regardless of 3 and 6 sampling points or estimated glomerular filtration rate. These results indicated the higher predictive accuracy of 2-point sampling than 1-point sampling on day 1 for amikacin AUC estimation. Moreover, 2-point sampling was a more reasonable approach than rich sampling., Conclusions: This study contributes to the development of an efficient model-informed precision dosing strategy for early targeting of amikacin AUC in critically ill patients., (© 2024 British Pharmacological Society.)

Aims: AP30663 is a novel compound under development for pharmacological conversion of atrial fibrillation by targeting the small conductance Ca 2+ activated K + (K Ca 2) channel. The aim of this extension phase 1 study was to test AP30663 at higher single doses compared to the first-in-human trial., Methods: Sixteen healthy male volunteers were randomized into 2 cohorts: 6- and 8-mg/kg intravenous single-dose administration of AP30663 vs. placebo. Safety, pharmacokinetic and pharmacodynamic data were collected., Results: AP30663 was associated with mild and transient infusion site reactions with no clustering of other adverse events but with an estimated maximum mean QTcF interval prolongation of 45.2 ms (95% confidence interval 31.5-58.9) in the 6 mg/kg dose level and 50.4 ms (95% confidence interval 36.7-64.0) with 8 mg/kg. Pharmacokinetics was dose proportional with terminal half-life of around 3 h., Conclusion: AP30663 in doses up to 8 mg/kg was associated with mild and transient infusion site reactions and an increase of the QTcF interval. Supporting Information support that the QTc effect may be explained by an off-target inhibition of the I Kr channel., (© 2023 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Artificial intelligence (AI) will impact many aspects of clinical pharmacology, including drug discovery and development, clinical trials, personalized medicine, pharmacogenomics, pharmacovigilance and clinical toxicology. The rapid progress of AI in healthcare means clinical pharmacologists should have an understanding of AI and its implementation in clinical practice. As with any new therapy or health technology, it is imperative that AI tools are subject to robust and stringent evaluation to ensure that they enhance clinical practice in a safe and equitable manner. This review serves as an introduction to AI for the clinical pharmacologist, highlighting current applications, aspects of model development and issues surrounding evaluation and deployment. The aim of this article is to empower clinical pharmacologists to embrace and lead on the safe and effective use of AI within healthcare., (© 2023 British Pharmacological Society.)

Aims: Our aim was to determine the absolute bioavailability, mass balance, metabolism and excretion of soticlestat (TAK-935)., Methods: An open-label, two-period, single-site, phase 1 study was conducted in six healthy men. In Period 1, a single 300 mg dose of soticlestat was administered orally, followed by a 15-min intravenous infusion of [ 14 C]soticlestat 50 μg (~1 μCi) 10 min later. In Period 2, a single 300 mg dose (~100 μCi) of [ 14 C]soticlestat in solution was administered orally. Samples were collected, analysed for radioactivity or unchanged soticlestat, and profiled for metabolites., Results: In Period 1, soticlestat had an absolute bioavailability of 12.6% (90% confidence interval, 7.81-20.23%). In Period 2, there was near-complete recovery of total radioactivity (TRA) following a 300 mg dose of [ 14 C]soticlestat: urine, 94.8% (standard deviation [SD], 1.35%); faeces, 2.7% (SD, 1.67%). Of TRA, 0.1% (SD, 0.09%) and 0.6% (SD, 0.21%) were recovered as soticlestat and metabolite M-I in urine, respectively. In plasma, soticlestat and M-I reached geometric mean maximum observed concentrations of 1352 ng/mL (geometric percent coefficient of variation [gCV%], 61.3) and 253.2 ng/mL (gCV%, 44.1) after 25 min and declined with mean terminal half-lives (SD) of 5.7 (2.90) and 2.0 (0.15) h, respectively. Soticlestat represented 4.9% of TRA in plasma. Soticlestat was rapidly eliminated primarily via O-glucuronidation to metabolite M3, which was the dominant species in plasma (92.6%) and urine (86%)., Conclusions: This study indicates that soticlestat and its metabolites are rapidly cleared and eliminated, lowering the risk of dose accumulation from repeated dosing and supporting further investigation of soticlestat., (© 2023 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Annual influenza vaccination is one of the main public health measures able to drastically reduce the burden of this infectious disease. Some evidence suggests 'trained immunity' triggered by influenza vaccine might reduce the risk of SARS-CoV-2 infection. Adjuvanted influenza vaccines are known to induce a broader cross-reactive immunity. No studies investigated the effect of adjuvanted vs. non-adjuvanted influenza vaccines on the risk of symptomatic SARS-CoV-2 infection. A case-control analysis nested in a cohort of subjects aged ≥65 years and immunized with adjuvanted or non-adjuvanted influenza vaccines was conducted. Although no statistically significant (OR = 0.87; P = .082) difference between the two vaccine types was observed for the 9-month follow-up period, a 17% (OR = 0.83; P = .042) reduction in the odds of COVID-19 was observed for adjuvanted vaccines with a 6-month follow-up. Further evidence is needed, but these results might have implications given the complexity of the upcoming winter seasons, in which the co-occurrence of influenza, SARS-CoV-2 and other respiratory infections (e.g., syncytial virus) might be unpredictable., (© 2023 British Pharmacological Society.)

Aims: The C-X-C chemokine receptor 3 (CXCR3) axis is highly upregulated in the tissue of patients with type 1 diabetes. Antagonizing CXCR3 may reduce the migration of CXCR3-expressing cells to the pancreas. The pharmacokinetics (PKs), target engagement (TE) (inhibition of CXCR3 internalization) and safety of single- and multiple-ascending doses (SADs and MADs) of ACT-777991, a novel orally available potent CXCR3 antagonist, were assessed in a double-blind, randomized, placebo-controlled phase 1 study., Methods: Doses up to 100 mg (SAD part) and 40 mg twice daily (MAD part) were investigated in a total of 70 male and female healthy participants. Food effect was integrated as an SAD subpart. PK, TE, safety and tolerability data were collected up to 4 days after (last) dosing., Results: In both SAD and MAD parts, ACT-777991 was rapidly absorbed with a time to reach maximum concentration between 0.5 and 1.5 h post dose, followed by a biphasic disposition with a terminal half-life between 9.7 and 10.3 h. Increase in exposure and maximum concentration of ACT-777991 were dose-proportional. Steady state was reached after 48 h with minimal accumulation. The rate but not the extent of absorption was modified by food intake. A dose-dependent TE was demonstrated in both SAD and MAD parts. ACT-777991 was well tolerated. Neither a treatment-related pattern nor a dose-response relationship was determined for adverse events or any safety variable. No QT prolongation liability of regulatory concern was detected., Conclusions: In this first-in-human study, ACT-777991 showed good tolerability for all doses tested and a PK and TE profile suitable for further clinical development., (© 2023 British Pharmacological Society.)

Aims: Ibrutinib is used in the treatment of certain B-cell malignancies. Due to its CYP3A4-mediated metabolism and highly variable pharmacokinetics, it is prone to potentially harmful drug-drug interactions., Methods: In a randomized, placebo-controlled, three-phase crossover study, we examined the effect of the CYP3A4-inhibiting antifungal posaconazole on ibrutinib pharmacokinetics. Eleven healthy participants ingested repeated doses of 300 mg of posaconazole either in the morning or in the evening, or placebo. A single dose of ibrutinib (30, 70 or 140 mg, respectively) was administered at 9 AM, 1 or 12 h after the preceding posaconazole/placebo dose., Results: On average, morning posaconazole increased the dose-adjusted geometric mean area under the plasma concentration-time curve from zero to infinity (AUC 0-∞ ) and peak plasma concentration (C max ) of ibrutinib 9.5-fold (90% confidence interval [CI] 6.3-14.3, P < 0.001) and 8.5-fold (90% CI 5.7-12.8, P < 0.001), respectively, while evening posaconazole increased those 10.3-fold (90% CI 6.7-16.0, P < 0.001) and 8.2-fold (90% CI 5.2-13.2, P < 0.001), respectively. Posaconazole had no significant effect on the half-life of ibrutinib, but substantially reduced the metabolite PCI-45227 to ibrutinib AUC 0-∞ ratio. There were no significant differences in ibrutinib pharmacokinetics between morning and evening posaconazole phases., Conclusions: Posaconazole increases ibrutinib exposure substantially, by about 10-fold. This interaction cannot be avoided by dosing the drugs 12 h apart. In general, a 70-mg daily dose of ibrutinib should not be exceeded during posaconazole treatment to avoid potentially toxic systemic ibrutinib concentrations., (© 2023 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: To describe characteristics of applicant, tool, outcomes, regulatory responses and general learnings from European Medicines Agency (EMA) Qualification Procedures on patient-reported outcomes (PROs), observer-reported outcomes (ObsROs) and performance outcomes (PerfOs) finalized between January 2013 and December 2018., Methods: Descriptive analysis, and qualitative review of the regulatory outcomes of the study procedures., Results: Seventeen qualification programmes for PROs, 6 for ObsRO tools and 11 for PerfO tools were submitted by consortia, large and small/medium companies. Gastroenterology and neurology were the most frequent therapeutic areas. There was a high level of regulators' partial agreement (above 70%) with applicant's approaches with constructive input; EMA published Letters of Support for PRO (6), ObsRO (2) and PerfO (4) tools, and Qualification Opinions on PROs (2) and PerfOs (1). General issues related to Qualification Procedures on PROs raised by EU regulatorsincluded: population, appropriate studies to demonstrate ability to detect change, tool validation in interventional trials, anchoring, identification of the minimally important difference, item selection, weighting, and multiple domains. In addition, specific issues for ObsROs and PerfO tools validation are identified., Conclusions: Regulators discussed principles and challenges of validation tailored to specific setting in tool development, providing constructive feedback. Regulatory outputs supportive of further development were published in over one-third of programs. We encourage applicants intending to use or develop novel PRO, ObsRO and PerfO tools that will generate evidence for regulatory submissions on medicines to consider Qualification procedures for novel methods to seek feedback on the development and validation of these tools., (© 2023 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Cytomegalovirus (CMV) infection frequently occurs after solid organ transplantation and is associated with an increased morbidity and mortality. Fortunately, the development of valganciclovir prophylaxis has lowered the incidence of CMV infection and its complications in immunosuppressed solid organ transplant recipients. However, breakthrough infections during valganciclovir prophylaxis and late CMV infection after cessation of valganciclovir prophylaxis still occur with the current prophylactic strategy. Additionally, valganciclovir resistance has emerged among CMV strains, which complicates the treatment of CMV infections. Furthermore, the use of valganciclovir is associated with myelotoxicity, which can lead to the premature withdrawal of prophylaxis. It is important to address these current issues in order to improve the standard care after solid organ transplantation. This paper will therefore discuss the clinical practice of valganciclovir prophylaxis, elaborate on its issues and suggest how to improve the current prophylactic strategy with a possible role for therapeutic drug monitoring., (© 2024 The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Measurement of pre-dose tacrolimus concentrations, also referred to as trough concentrations or C0 (in this paper the term C0 will be used), is the most frequently used parameter for therapeutic drug monitoring in patients after solid organ transplantation. C0 is relatively easy to obtain, and can be combined with other lab tests. C0 monitoring is convenient for patient and hospital staff. Adjusting the dose based on C0 assumes that the C0 has a good correlation with the overall exposure to the drug, as reflected in the area under concentration-time curve (AUC). However, C0 may not be the panacea it is suggested to be, and there are patients who may benefit from additional measurements to more precisely assess drug exposure. Especially in patients with a low C0/dose ratio, the peak tacrolimus concentrations after oral administration may be unexpectedly high, resulting in toxicity and (as has been shown already) in poor long-term graft survival. At the other extreme, patients who only need a very low dose to reach target C0 may have a low peak and also a low AUC and may be underexposed. In this paper, the limitations of C0 will be discussed, and the type of studies needed to provide the evidence for implementation of more sophisticated therapeutic drug monitoring. The paper focuses on treatment of adult kidney transplant recipients., (© 2024 The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)