The thesis describes the use of extensive pharmacodynamic effect profiling to characterise the clinical pharmacology of classic and non-classical analgesia. Analgesic drugs that modulate widespread... Show moreThe thesis describes the use of extensive pharmacodynamic effect profiling to characterise the clinical pharmacology of classic and non-classical analgesia. Analgesic drugs that modulate widespread targets in the nervous system can be expected to affect numerous CNS functions, which requires multimodal characterisation of pain processing and neurocognition. This is illustrated on the basis of two case studies of pharmacological agents that target cannabinoid CB1 and GABA-ergic GABAA receptors: two of the most widely distributed systems of receptors and neurotransmitters that are involved in a myriad of physiological functions. The distribution of receptors throughout the central nervous system render an oral formulation of ∆9-THC and a positive allosteric modulator of α2/3/5 subunit-containing GABAA receptors, ideal candidates for extensive neurophysiological and analgesic effect profiling in early phase clinical research. Profiling human pharmacology with a strong focus on pharmacodynamics may help to better understand the therapeutic potential and safety limitations of a compound before selection of doses and patient populations for phase II proof-of-concept studies. Show less
Drug development scientists are on a search for suitable biomarkers that can assist in predicting the therapeutic potential of analgesic medication and, therefore, it’s efficacy in the target... Show moreDrug development scientists are on a search for suitable biomarkers that can assist in predicting the therapeutic potential of analgesic medication and, therefore, it’s efficacy in the target population. This is particularly appropriate for human pain where models can assist to bridge the preclinical and clinical findings. These models can provide valuable information about the mechanism of action of existing and new drugs. However, a single human pain model cannot be used exclusively to screen the pharmacological mechanism of a compound as it inherently only tests a single mechanism. In this thesis the performance of a battery of pain models (PainCart) was investigated. Three main topics were investigated. (1) The validation of the PainCart was described in which the effects of different classes of analgesics on this battery of pain models were explored. (2) The PainCart was used in different chronic pain populations. (3) The performance of the battery during the development of new analgesic compounds was studied. The battery of pain models can act as biomarker to assess the effect of analgesics on pain. It can be used to benchmark analgesic properties of new drugs against established analgesics in early phase clinical studies. Show less
The endocannabinoid system has only been discovered during the last few decades, and scientific progress in understanding the relevance of this system in health and disease has been limited and... Show moreThe endocannabinoid system has only been discovered during the last few decades, and scientific progress in understanding the relevance of this system in health and disease has been limited and slow. CB1 antagonists were considered a __miracle drug__ for the treatment of obesity and smoking with __blockbuster__ potential. But due to central side effects (such as depression and suicidal behaviour) and a lack of systematic clinical pharmacologic research, market access of a CB1 antagonists failed. In this thesis, we explored some improvements in the early development of cannabinoids, and by systematically investigating, we found that the new cannabinoid antagonist TN38837 seems effective with a reduced propensity for central side effects, and that a new oral THC formulation enhances the pharmacological activities by its seemingly superior pharmacokinetics. Also, we experiment with new methodology to optimise effect measurement, including resting state-FMRI which we found suitable for early phase cannabinoid research, and including new concentration-effect models to improve the simulation and prediction of future studies. The research in this thesis shows that a revival of research on the cannabinoid system requires novel approaches to the administration of cannabinoids, to the measurements and the study designs, and to the analyses of the effects. This reflects the complexity of the highly integrated endocannabinoid system, but also sets the stage for other innovative drug development programs Show less
This thesis covers a variety of topics around the central theme of pharmacological research involving children, with a specific focus on the development of minimally invasive methodology that can... Show moreThis thesis covers a variety of topics around the central theme of pharmacological research involving children, with a specific focus on the development of minimally invasive methodology that can be employed in future studies involving children. Children form a unique group within the area of pharmacological research and pharmacotherapy. The heterogeneity even within this group is large, covering the range of preterm neonates weighing 500 grams up to adolescents. Obviously, therapeutic needs change across this range, as among others disease epidemiology, drug disposition, pharmacodynamic response, and suitable drug formulations change with age. The same holds true for the design of drug trials involving children: where pharmacokinetics in adults can be studied simply by recruiting a number of healthy volunteers, such a study with a number of healthy toddlers is clearly not feasible and not acceptable. Therefore, approaches and new methodology are needed to circumvent these issues. Show less
