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The British Journal of Clinical Pharmacology celebrates its 50th anniversary of publication in 2023. Here four previous Editors-in-Chief and the current Editor reflect on the Journal's history and the changes that have occurred during that time.
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Publicações Periódicas como Assunto , Farmacologia ClínicaRESUMO
INTRODUCTION: The recent introduction of the European Medical Device Regulation poses stricter legislation for manufacturers developing medical devices in the EU. Many devices have been placed into a higher risk category, thus requiring more data before market approval, and a much larger focus has been placed on safety. For implantable and Class III devices, the highest risk class, clinical evidence is a necessity. However, the requirements of clinical study design and developmental outcomes are only described in general terms due to the diversity of devices. METHODS: A structured approach to determining the requirements for the clinical development of high-risk medical devices is introduced, utilizing the question-based development framework, which is already used for pharmaceutical drug development. An example of a novel implantable device for haemodialysis demonstrates how to set up a relevant target product profile defining the device requirements and criteria. The framework can be used in the medical device design phase to define specific questions to be answered during the ensuing clinical development, based upon five general questions, specified by the question-based framework. RESULTS: The result is a clear and evaluable overview of requirements and methodologies to verify and track these requirements in the clinical development phase. Development organizations will be guided to the optimal route, also to abandon projects destined for failure early on to minimize development risks. CONCLUSION: The framework could facilitate communication with funding agencies, regulators and clinicians, while highlighting remaining 'known unknowns' that require answering in the post-market phase after sufficient benefit is established relative to the risks.
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Comunicação , Desenvolvimento de Medicamentos , Humanos , Desenho de EquipamentoRESUMO
BACKGROUND: Digital biomarkers are a promising novel method to capture clinical data in a home setting. However, clinical validation prior to implementation is of vital importance. The aim of this study was to clinically validate physical activity, heart rate, sleep and forced expiratory volume in 1â s (FEV1) as digital biomarkers measured by a smartwatch and portable spirometer in children with asthma and cystic fibrosis (CF). METHODS: This was a prospective cohort study including 60 children with asthma and 30 children with CF (aged 6-16â years). Participants wore a smartwatch, performed daily spirometry at home and completed a daily symptom questionnaire for 28â days. Physical activity, heart rate, sleep and FEV1 were considered candidate digital end-points. Data from 128 healthy children were used for comparison. Reported outcomes were compliance, difference between patients and controls, correlation with disease activity, and potential to detect clinical events. Analysis was performed with linear mixed effects models. RESULTS: Median compliance was 88%. On average, patients exhibited lower physical activity and FEV1 compared with healthy children, whereas the heart rate of children with asthma was higher compared with healthy children. Days with a higher symptom score were associated with lower physical activity for children with uncontrolled asthma and CF. Furthermore, FEV1 was lower and (nocturnal) heart rate was higher for both patient groups on days with more symptoms. Candidate biomarkers appeared able to describe a pulmonary exacerbation. CONCLUSIONS: Portable spirometer- and smartwatch-derived digital biomarkers show promise as candidate end-points for use in clinical trials or clinical care in paediatric lung disease.
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Asma , Fibrose Cística , Biomarcadores , Criança , Volume Expiratório Forçado , Humanos , Estudos Prospectivos , EspirometriaRESUMO
The creation of WADA contributed to harmonization of anti-doping and changed doping behavior and prevalence in the past 22 years. However, the system has developed important deficiencies and limitations that are causing harm to sports, athletes and society. These issues are related to the lack of evidence for most substances on the Prohibited List for performance or negative health effects, a lack of transparency and accountability of governance and decision-making by WADA and the extension of anti-doping policies outside the field of professional sports. This article tries to identify these deficiencies and limitations and presents a plea for more science, better governance and more education. This should lead to a discussion for reform among stakeholders, which should cover support of a new Prohibited List by actual research and evidence and introduce better governance with accountable control bodies and regulation. Finally, comprehensive education for all stakeholders will be the basis of all future positive improvements.
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Dopagem Esportivo , Esportes , Atletas , Dopagem Esportivo/prevenção & controle , HumanosRESUMO
AIMS: During phase I study conduct, blinded data are reviewed to predict the safety of increasing the dose level. The aim of the present study was to describe the probability that effects are observed in blinded evaluations of data in a simulated phase I study design. METHODS: An application was created to simulate blinded pharmacological response curves over time for 6 common safety/efficacy measurements in phase I studies for 1 or 2 cohorts (6 active, 2 placebo per cohort). Effect sizes between 0 and 3 between-measurement standard deviations (SDs) were simulated. Each set of simulated graphs contained the individual response and mean ± SD over time. Reviewers (n = 34) reviewed a median of 100 simulated datasets and indicated whether an effect was present. RESULTS: Increasing effect sizes resulted in a higher chance of the effect being identified by the blinded reviewer. On average, 6% of effect sizes of 0.5 between-measurement SD were correctly identified, increasing to 72% in 3.0 between-measurement SD effect sizes. In contrast, on average 92-95% of simulations with no effect were correctly identified, with little effect of between-measurement variability in single cohort simulations. Adding a dataset of a second cohort at half the simulated dose did not appear to improve the interpretation. CONCLUSION: Our analysis showed that effect sizes <2× the between-measurement SD of the investigated outcome frequently go unnoticed by blinded reviewers, indicating that the weight given to these blinded analyses in current phase I practice is inappropriate and should be re-evaluated.
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Ensaios Clínicos Fase I como Assunto , Humanos , Estudos de Viabilidade , Interpretação Estatística de DadosRESUMO
AIM: Traditional studies focusing on the relationship between pharmacokinetics (PK) and pharmacodynamics necessitate blood draws, which are too invasive for children or other vulnerable populations. A potential solution is to use noninvasive sampling matrices, such as saliva. The aim of this study was to develop a population PK model describing the relationship between plasma and saliva clonazepam kinetics and assess whether the model can be used to determine trough plasma concentrations based on saliva samples. METHODS: Twenty healthy subjects, aged 18-30, were recruited and administered 0.5 or 1 mg of clonazepam solution. Paired plasma and saliva samples were obtained until 48 hours post-dose. A population pharmacokinetic model was developed describing the PK of clonazepam in plasma and the relationship between plasma and saliva concentrations. Bayesian maximum a posteriori optimization was applied to estimate the predictive accuracy of the model. RESULTS: A two-compartment distribution model best characterized clonazepam plasma kinetics with a mixture component on the absorption rate constants. Oral administration of the clonazepam solution caused contamination of the saliva compartment during the first 4 hours post-dose, after which the concentrations were driven by the plasma concentrations. Simulations demonstrated that the lower and upper limits of agreements between true and predicted plasma concentrations were -28% to 36% with one saliva sample. Increasing the number of saliva samples improved these limits to -18% to 17%. CONCLUSION: The developed model described the salivary and plasma kinetics of clonazepam, and could predict steady-state trough plasma concentrations based on saliva concentrations with acceptable accuracy.
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Clonazepam , Saliva , Teorema de Bayes , Criança , Clonazepam/farmacocinética , Humanos , Plasma , Populações VulneráveisRESUMO
OBJECTIVE: The aim of the present study was to develop a neural network to characterize the effect of aging on the ECG in healthy volunteers. Moreover, the impact of the various ECG features on aging was evaluated. METHODS & RESULTS: A total of 6228 healthy subjects without structural heart disease were included in this study. A neural network regression model was created to predict age of the subjects based on their ECG; 577 parameters derived from a 12lead ECG of each subject were used to develop and validate the neural network; A tenfold cross-validation was performed, using 118 subjects for validation each fold. Using SHapley Additive exPlanations values the impact of the individual features on the prediction of age was determined. Of 6228 subjects tested, 1808 (29%) were females and mean age was 34 years, range 18-75 years. Physiologic age was estimated as a continuous variable with an average error of 6.9 ± 5.6 years (R2 = 0.72 ± 0.04). The correlation was slightly stronger for men (R2 = 0.74) than for women (R2 = 0.66). The most important features on the prediction of physiologic age were T wave morphology indices in leads V4 and V5, and P wave amplitude in leads AVR and II. CONCLUSION: The application of machine learning to the ECG using a neural network regression model, allows accurate estimation of physiologic cardiac age. This technique could be used to pick up subtle age-related cardiac changes, but also estimate the reversing of these age-associated effects by administered treatments.
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Benchmarking , Eletrocardiografia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Eletrocardiografia/métodos , Feminino , Voluntários Saudáveis , Humanos , Lactente , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Redes Neurais de Computação , Adulto JovemRESUMO
BACKGROUND: The field of obstetrics and gynecology requires complex decision-making and skills because of unexpected high-risk situations. These skills are influenced by alertness, reaction time, and concentration. Night shifts result in sleep deprivation, which might impair these functions, although it is still unclear to what extent. OBJECTIVE: This study aimed to investigate whether a night shift routinely impairs the obstetrics and gynecology consultants' and residents' fitness to perform and whether this reaches a critical limit compared with relevant frames of reference. STUDY DESIGN: Residents (n=33) and consultants (n=46) in obstetrics and gynecology conducted multiple measurements (n=415) at precall, postcall, and noncall moments with the fitness to perform self-test. The self-test consists of an adaptive pursuit tracking task that is able to objectively measure alertness, reaction time, concentration, and hand-eye coordination and Visual Analog Scale tests to subjectively score alertness. The test is validated with a sociolegal reference of a 0.06% ethanol blood concentration (the peak level after 2 units of alcohol, the legal driving limit). This equals -1.37% on the objective score and -8.17 points on subjective alertness. Linear mixed models were used to analyze the difference within subjects over a night shift, integrating repeated measures over time. RESULTS: The overnight objective difference between postcall and precall measurements was -0.62 (P<.05) for residents and 0.28 (P=NS) for consultants, both not exceeding the sociolegal reference as a group. Objective impairment exceeded the reference for 31% of the residents and 28% of the consultants. Subjective alertness decreased in residents (-18.26; P<.001) and consultants (-10.85; P<.001), both exceeding the reference. No residents had to continue work postcall versus 7.8% of the consultants. None of the consultants that had to continue work were in an objective critically impaired state. CONCLUSION: This study provides insight and awareness of individual performance after night shifts with clear frames of reference. The performance of residents is negatively and significantly affected by night shifts; therefore, a scheduled day off after a night shift is justified. Consultants showed no overall impairment; however, a quarter did exceed the alcohol limit reference after their night shift. If not logistically feasible to schedule a protected day off after a night shift, our group recommends safe shift scheduling, including options to transfer care after a demanding night shift to prevent working in a compromised state.
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Competência Clínica , Ginecologia , Privação do Sono , Análise e Desempenho de Tarefas , Tolerância ao Trabalho Programado , Adulto , Competência Clínica/normas , Competência Clínica/estatística & dados numéricos , Consultores , Fadiga/etiologia , Fadiga/fisiopatologia , Fadiga/psicologia , Feminino , Ginecologia/educação , Ginecologia/normas , Humanos , Internato e Residência , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Países Baixos , Segurança do Paciente , Estudos Prospectivos , Melhoria de Qualidade , Reprodutibilidade dos Testes , Privação do Sono/etiologia , Privação do Sono/fisiopatologia , Privação do Sono/psicologia , Tolerância ao Trabalho Programado/fisiologia , Tolerância ao Trabalho Programado/psicologiaRESUMO
During the outbreak of the COVID-19 pandemic many clinical trials were abruptly halted. Measures to contain the pandemic are currently taking effect and societies in general and healthcare systems in particular are considering how to return to normalcy. This opens up the discussion when and how clinical trials should be restarted while the COVID-19 pandemic has not yet resolved, and what should happen in case of a resurgence of the virus in the coming months. This article uses the four ethical principles framework as a structured approach to come to a set of practical, ethically grounded guidelines for halting and relaunching clinical trials during the COVID-19 pandemic. The framework applied provides a structured approach for all clinical trials stakeholders and thereby prevents unclear reasoning in a complex situation. While it is essential to prevent the virus from resurging and focus on developing a COVID-19 treatment as soon as possible, it is just as important to our society that we continue developing new drugs for other conditions. In this article we argue that the situation for clinical trials is not essentially different from the pre-COVID-19 era and that an overcautious approach will have negative consequences.
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COVID-19 , Ensaios Clínicos como Assunto/ética , Ensaios Clínicos como Assunto/métodos , Análise Ética , Pandemias , Humanos , Projetos de PesquisaRESUMO
BACKGROUND: Historically, pharmacokinetic (PK) studies and therapeutic drug monitoring (TDM) have relied on plasma as a sampling matrix. Noninvasive sampling matrices, such as saliva, can reduce the burden on pediatric patients. The variable plasma-saliva relationship can be quantified using population PK models (nonlinear mixed-effect models). However, criteria regarding acceptable levels of variability in such models remain unclear. In this simulation study, the authors aimed to propose a saliva TDM evaluation framework and evaluate model requirements in the context of TDM, with gentamicin and lamotrigine as model compounds. METHODS: Two population pharmacokinetic models for gentamicin in neonates and lamotrigine in pediatrics were extended with a saliva compartment including a delay constant (kSALIVA), a saliva:plasma ratio, and between-subject variability (BSV) on both parameters. Subjects were simulated using a realistic covariate distribution. Bayesian maximum a posteriori TDM was applied to assess the performance of an increasing number of TDM saliva samples and varying levels of BSV and residual variability. Saliva TDM performance was compared with plasma TDM performance. The framework was applied to a known voriconazole saliva model as a case study. RESULTS: TDM performed using saliva resulted in higher target attainment than no TDM, and a residual proportional error <25% on saliva observations led to saliva TDM performance comparable with plasma TDM. BSV on kSALIVA did not affect performance, whereas increasing BSV on saliva:plasma ratios by >25% for gentamicin and >50% for lamotrigine reduced performance. The simulated target attainment for voriconazole saliva TDM was >90%. CONCLUSIONS: Saliva as an alternative matrix for noninvasive TDM is possible using nonlinear mixed-effect models combined with Bayesian optimization. This article provides a workflow to explore TDM performance for compounds measured in saliva and can be used for evaluation during model building.
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Monitoramento de Medicamentos/métodos , Saliva , Teorema de Bayes , Criança , Humanos , Recém-Nascido , Dinâmica não Linear , Pediatria , Saliva/químicaRESUMO
BACKGROUND: Pediatric patients admitted for acute lung disease are treated and monitored in the hospital, after which full recovery is achieved at home. Many studies report in-hospital recovery, but little is known regarding the time to full recovery after hospital discharge. Technological innovations have led to increased interest in home-monitoring and digital biomarkers. The aim of this study was to describe at-home recovery of 3 common pediatric respiratory diseases using a questionnaire and wearable device. METHODS: In this study, patients admitted due to pneumonia (n = 30), preschool wheezing (n = 30), and asthma exacerbation (AE; n = 11) were included. Patients were monitored with a smartwatch and a questionnaire during admission, with a 14-day recovery period and a 10-day "healthy" period. Median compliance was calculated, and a mixed-effects model was fitted for physical activity and heart rate (HR) to describe the recovery period, and the physical activity recovery trajectory was correlated to respiratory symptom scores. RESULTS: Median compliance was 47% (interquartile range [IQR] 33-81%) during the entire study period, 68% (IQR 54-91%) during the recovery period, and 28% (IQR 0-74%) during the healthy period. Patients with pneumonia reached normal physical activity 12 days postdischarge, while subjects with wheezing and AE reached this level after 5 and 6 days, respectively. Estimated mean physical activity was closely correlated with the estimated mean symptom score. HR measured by the smartwatch showed a similar recovery trajectory for subjects with wheezing and asthma, but not for subjects with pneumonia. CONCLUSIONS: The digital biomarkers, physical activity, and HR obtained via smartwatch show promise for quantifying postdischarge recovery in a noninvasive manner, which can be useful in pediatric clinical trials and clinical care.
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Asma , Pneumonia , Doença Aguda , Assistência ao Convalescente , Biomarcadores , Criança , Pré-Escolar , Humanos , Alta do Paciente , Sons RespiratóriosRESUMO
Concentrations of drugs acting in the lungs are difficult to measure, resulting in relatively unknown local pharmacokinetics. The aim of this study is to assess the potential of exhaled breath condensate (EBC) as a matrix for pharmacokinetic analysis of inhaled and intravenous medication. A 4-way crossover study was conducted in 12 volunteers with tobramycin and salbutamol intravenously and via inhalation. EBC and plasma samples were collected postdose and analysed for drug concentrations. Sample dilution, calculated using urea concentrations, was used to estimate the epithelial lining fluid concentration. Salbutamol and tobramycin were largely undetectable in EBC after intravenous administration and were detectable after inhaled administration in all subjects in 50.8 and 51.5% of EBC samples, respectively. Correction of EBC concentrations for sample dilution did not explain the high variability. This high variability of EBC drug concentrations seems to preclude EBC as a matrix for pharmacokinetic analysis of tobramycin and salbutamol.
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Albuterol , Tobramicina , Administração Intravenosa , Biomarcadores , Testes Respiratórios , Estudos Cross-Over , HumanosRESUMO
PURPOSE: Recombinant human erythropoietin (rHuEPO) is known to increase thrombotic risk in patients and might have similar effects in athletes abusing the drug. rHuEPO is prohibited by anti-doping legislation, but this risk has not been investigated thoroughly. This analysis was designed to evaluate whether rHuEPO impacts hemostatic profile and endothelial and platelet activation markers in trained subjects, and whether the combination with exercise affects exercise induced alterations. METHODS: This double-blind, randomized, placebo-controlled trial enrolled healthy, trained male cyclists aged 18-50 years. Participants were randomly allocated (1:1) to receive subcutaneous injections of rHuEPO (epoetin-ß; mean dose 6000 IU per week) or placebo (0.9% NaCl) for 8 weeks. Subjects performed five maximal exercise tests and a road race, coagulation and endothelial/platelet markers were measured at rest and directly after each exercise effort. RESULTS: rHuEPO increased P-selectin (+ 7.8% (1.5-14.5), p = 0.02) and E-selectin (+ 8.6% (2.0-15.7), p = 0.01) levels at rest. Maximal exercise tests significantly influenced all measured coagulation and endothelial/platelet markers, and in the rHuEPO group maximal exercise tests led to 15.3% ((7.0-24.3%), p = 0.0004) higher E-selectin and 32.1% ((4.6-66.8%), p = 0.0207) higher Platelet factor 4 (PF4) levels compared to the placebo group. CONCLUSION: In conclusion, rHuEPO treatment resulted in elevated E- and P-selectin levels in trained cyclists, indicating enhanced endothelial activation and/or platelet reactivity. Exercise itself induces hypercoagulability, and the combination of rHuEPO and exercise increased E-selectin and PF4 levels more than either intervention alone. Based on this, exercise potentially increases thrombotic risk, a risk that might be enhanced in combination with rHuEPO use.
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Coagulação Sanguínea/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Eritropoetina/farmacologia , Exercício Físico , Adulto , Atletas , Endotélio Vascular/metabolismo , Eritropoetina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/efeitos dos fármacos , Selectinas/metabolismoRESUMO
BACKGROUND: Surgical skills and decision making are influenced by alertness, reaction time, eye-hand coordination, and concentration. Night shift might impair these functions but it is unclear to what extent. The aim of this study was to investigate whether a night shift routinely impairs the surgeon's fitness to perform and whether this reaches a critical limit as compared to relevant frames of reference. METHODS: Consultants (n = 59) and residents (n = 103) conducted fitness to perform measurements at precall, postcall, and noncall moments. This validated self-test consists of an adaptive tracker that is able to objectively measure alertness, reaction time, concentration, and eye-hand coordination, and multiple visual analog scales to subjectively score alertness. Results are compared to sociolegal (ethanol) and professional (operative skills) frames of reference that refer to a decrease under the influence of 0.06% ethanol. RESULTS: Residents spent 1.7 call hours asleep on average as compared to 5.4 for consultants. Subjective alertness decreased in residents after night shifts (-13, P < 0.001) but not in consultants (-1.2, Pâ=âNS). The overnight difference in tracker score was -1.17 (P < 0.001) for residents and 0.46 (Pâ=âNS) for surgeons. Postcall subjective alertness only correlated to objective alertness in consultants. For residents, hours slept on-call correlated to objective alertness. For consultants, subsequent night calls significantly correlated to objective alertness, with the third subsequent call related to performance below the reference. CONCLUSIONS: Consultants remain fit to perform after night call, but subsequent calls may compromise clinical activities. This study provides insight and awareness of individual performance with clear frames of reference.
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Plantão Médico/métodos , Competência Clínica , Fadiga/fisiopatologia , Aptidão Física/fisiologia , Autoavaliação (Psicologia) , Tolerância ao Trabalho Programado , Atenção/fisiologia , Estudos de Coortes , Consultores , Fadiga/epidemiologia , Feminino , Cirurgia Geral/educação , Humanos , Internato e Residência , Masculino , Países Baixos , Estudos Prospectivos , Reprodutibilidade dos Testes , Cirurgiões , Análise e Desempenho de TarefasRESUMO
Clinical trials have been conducted since 500 BC. Currently, the methodological gold standard is the randomized controlled clinical trial, introduced by Austin Bradford Hill. This standard has produced enormous amounts of high-quality evidence, resulting in evidence-based clinical guidelines for physicians. However, the current trial paradigm needs to evolve because of the ongoing decrease of the incidence of hard endpoints and spiraling trial costs. While new trial designs, such as adaptive clinical trials, may lead to an increase in efficiency and decrease in costs, we propose a shift towards value-based trial design: a paradigm that mirrors value-based thinking in business and health care. Value-based clinical trials will use technology to focus more on symptoms and endpoints that patients care about, will incorporate fewer research centers, and will measure a state or consequence of disease at home or at work. Furthermore, they will measure the subjective experience of subjects in relation to other objective measurements. Ideally, the endpoints are suitable for individual assessment of the effect of an intervention. The value-based clinical trial of the future will have a low burden for participants, allowing for the inclusion of neglected populations such as children and the elderly, will be data-rich due to a high frequency of measurements, and can be conducted with technology that is already available.
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Ensaios Clínicos como Assunto/normas , Projetos de Pesquisa/tendências , HumanosRESUMO
Therapeutic drug monitoring is routinely performed to maintain optimal tacrolimus concentrations in kidney transplant recipients. Nonetheless, toxicity and rejection still occur within an acceptable concentration-range. To have a better understanding of the relationship between tacrolimus dose, tacrolimus concentration, and its effect on the target cell, we developed functional immune tests for the quantification of the tacrolimus effect. Twelve healthy volunteers received a single dose of tacrolimus, after which intracellular and whole blood tacrolimus concentrations were measured and were related to T cell functionality. A significant correlation was found between tacrolimus concentrations in T cells and whole blood concentrations (r = 0.71, p = 0.009), while no correlation was found between tacrolimus concentrations in peripheral blood mononuclear cells (PBMCs) and whole blood (r = 0.35, p = 0.27). Phytohemagglutinin (PHA) induced the production of IL-2 and IFNγ, as well as the inhibition of CD71 and CD154 expression on T cells at 1.5 h post-dose, when maximum tacrolimus levels were observed. Moreover, the in vitro tacrolimus effect of the mentioned markers corresponded with the ex vivo effect after dosing. In conclusion, our results showed that intracellular tacrolimus concentrations mimic whole blood concentrations, and that PHA-induced cytokine production (IL-2 and IFNγ) and activation marker expression (CD71 and CD154) are suitable readout measures to measure the immunosuppressive effect of tacrolimus on the T cell.
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Monitoramento de Medicamentos , Leucócitos Mononucleares/imunologia , Tacrolimo , Adolescente , Adulto , Antígenos CD/imunologia , Ligante de CD40/imunologia , Feminino , Humanos , Interferon gama/imunologia , Interleucina-2/imunologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Fito-Hemaglutininas/farmacologia , Receptores da Transferrina/imunologia , Tacrolimo/administração & dosagem , Tacrolimo/farmacocinéticaRESUMO
AIMS: Salbutamol is used in the management of obstructive bronchospasm, including that of some elite athletes. It is claimed that high salbutamol (oral) doses may also have an anabolic effect. Therefore, inhalation of salbutamol is restricted by the World Anti-Doping Agency (WADA) to a maximal daily dose. Urine is tested for violations, but recent cases have resulted in a debate regarding the validity of this approach. It was our aim to determine whether current approaches are sufficiently able to differentiate approved usage from violations. METHODS: We extracted pharmacokinetic parameters from literature for salbutamol and its sulphated metabolite. From these parameters, a semi-physiological pharmacokinetic model of inhaled and orally administered salbutamol was synthesized, validated against literature data, and used to perform clinical trial simulations (n = 1000) of possible urine concentrations over time resulting from WADA-allowed and oral unacceptable dosages. RESULTS: The synthesized model was able to predict the literature data well. Simulations showed a very large range of salbutamol concentrations, with a significant portion of virtual subjects (15.4%) exceeding the WADA threshold limit of 1000 ng ml-1 at 1 h post-dose. CONCLUSIONS: The observed large variability in urine concentrations indicates that determining the administered dose from a single untimed urine sample is not feasible. The current threshold inadvertently leads to incorrect assumptions of violation, whereas many violations will go unnoticed, especially when samples are taken long after drug administration. These issues, combined with the dubious assertion of its anabolic effect, leads us to conclude that the large effort involved in testing should be reconsidered.
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Albuterol/urina , Anabolizantes/urina , Dopagem Esportivo/prevenção & controle , Futilidade Médica , Modelos Biológicos , Administração por Inalação , Administração Oral , Adulto , Albuterol/administração & dosagem , Albuterol/farmacocinética , Anabolizantes/administração & dosagem , Anabolizantes/farmacocinética , Variação Biológica da População/fisiologia , Espasmo Brônquico/tratamento farmacológico , Espasmo Brônquico/urina , Dopagem Esportivo/métodos , Reações Falso-Negativas , Reações Falso-Positivas , Estudos de Viabilidade , Humanos , Eliminação Renal/fisiologiaRESUMO
AIMS: Establishing a pharmacological challenge model could yield an important tool to understand the complex role of the nicotinic cholinergic system in cognition and to develop novel compounds acting on the nicotinic acetylcholine receptor. METHODS: This randomized, double-blind, double-dummy, placebo-controlled, four-way crossover study examined the effects of the nicotinic antagonist mecamylamine on a battery of cognitive and neurophysiological test with coadministration of a placebo, nicotine or galantamine in order to reverse the cognitive impairment caused by mecamylamine. RESULTS: Thirty-three healthy subjects received a single oral dose of 30 mg of mecamylamine (or placebo) in combination with either 16 mg of oral galantamine or 21 mg of transdermal nicotine (or its double-dummy). Mecamylamine 30 mg induced significant disturbances of cognitive functions. Attention and execution of visual (fine) motor tasks was decreased, short- and long-term memory was impaired and the reaction velocity during the test was slower when compared to placebo. Mecamylamine 30 mg produced a decrease in posterior α and ß power in the surface electroencephalogram, effects that were reversed by nicotine coadministration. Memory and motor coordination tests could be partially reversed by the coadministration of nicotine. CONCLUSIONS: Mecamylamine administration induced slowing of the electroencephalogram and produced decrease in performance of tests evaluating motor coordination, sustained attention and short- and long-term memory. These effects could be partially reversed by the coadministration of nicotine, and to a lesser extent by galantamine.
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Cognição/efeitos dos fármacos , Eletroencefalografia/efeitos dos fármacos , Galantamina/farmacologia , Mecamilamina/antagonistas & inibidores , Nicotina/farmacologia , Adolescente , Adulto , Estudos Cross-Over , Método Duplo-Cego , Interações Medicamentosas , Voluntários Saudáveis , Humanos , Masculino , Mecamilamina/farmacologia , Pessoa de Meia-Idade , Agonistas Nicotínicos/farmacologia , Antagonistas Nicotínicos/farmacologia , Tempo de Reação/efeitos dos fármacos , Adulto JovemRESUMO
AIMS: The aims of the present study were to investigate the role of pharmacology in the design of first-in-man (FIM) trials in the Netherlands, and to evaluate the change in design approaches between 2007 and 2015. METHODS: All FIM drug trials approved by all Dutch Institutional Review Boards (IRBs) in 2007 and in 2015 were selected. The original trial protocols, investigator's brochures and investigational medicinal product dossiers were the data sources. The following four design elements were assessed on the justification of the chosen approaches: preclinical information, dose calculation, endpoints, and dose escalation. RESULTS: In 2007, the Dutch IRBs approved 21 FIM trials, and in 2015 they approved 34 FIM trials (55 in total). Seven out of 21 (33%) of the FIM trials from 2007, and 14 out of the 34 (41%) FIM trials from 2015 discussed only the no-observed-adverse-effect level or no-observed-effect level as preclinical information. Furthermore, five of the 21 (24%) 2007 FIM trials and 12 of the 34 (35%) 2015 FIM trials used unexplained allometric scaling. Pharmacodynamic (PD) parameters were measured in 15 of the 21 (71%) 2007 FIM trials and in 31 of the 34 (91%) of the 2015 FIM trials, and allometric scaling was only guided by safety/tolerability in 11 of the 20 (55%) dose escalation trials in 2007 and in nine of the 33 (27%) dose escalation trials in 2015. CONCLUSIONS: Trial protocols and investigator's brochures commonly lack pharmacokinetic/PD approaches. Investigators, sponsors and IRBs should require an upfront consideration of pharmacology in these aspects for all FIM trials.
Assuntos
Ensaios Clínicos como Assunto/métodos , Preparações Farmacêuticas/administração & dosagem , Projetos de Pesquisa/tendências , Bases de Dados Factuais , Relação Dose-Resposta a Droga , Cálculos da Dosagem de Medicamento , Avaliação Pré-Clínica de Medicamentos/tendências , Determinação de Ponto Final/tendências , Humanos , Países Baixos , Nível de Efeito Adverso não Observado , Farmacocinética , Fatores de TempoRESUMO
Over the past 10 years, thousands of first-into-human (FIH) clinical trials have been performed in Europe, with few severe adverse events (SAEs). Each has received detailed prior safety review at both the local clinical research facility and at national drug regulatory authority level. The recent fatal SAE in the BIA-102474-101 clinical trial shows the limitations of this process. Although criticized for not sequentially dosing subjects both within and between cohorts - as recommended by the European Medicines Agency for high-risk compounds after the TeGenero clinical trial disaster in 2006 - BIA-102474-101 was not considered to be high risk. Indeed, compounds with similar mechanisms of action had previously been taken through phase I and II trials without incident, and higher doses had been safely given for longer durations to nonhuman primates. If the available data are comprehensive and accurate, and further investigation does not reveal unreported warning signs, this study has serious implications for ongoing and future review of FIH clinical trials. All preclinical study documents and clinical data collected during the BIA-102474-101 trial should be made available urgently so that lessons can be learnt. In the meantime, reviewers and clinical researchers should always ask for information on drug and target interactions and full reports of preclinical toxicity studies, and plan sequential dosing with longer delays between patients and cohorts, particularly if late SAEs might be anticipated. The use of individual patient pharmacokinetic and dynamic data should guide sequential dosing. A process for systematic risk assessment, like that currently used in the Netherlands, should be applied routinely to all trials with novel compounds.