Prematurely born neonates require, amongst others, pharmaceutical therapy. Dosing guidelines for these therapies are often based on data from term born neonates or older infants, while these are... Show morePrematurely born neonates require, amongst others, pharmaceutical therapy. Dosing guidelines for these therapies are often based on data from term born neonates or older infants, while these are not necessarily similar to prematurely born neonates. When suboptimal dosing guidelines are applied the neonates are at risk for under- or overdosing. In this thesis the pharmacokinetics and pharmacodynamics of a variety of drugs frequently used in preterm neonates were characterized, ultimately to optimize treatment. Specifically, caffeine, ibuprofen and fluconazole were studied which are drugs to treat apnea of prematurity, to close a patent ductus arteriosus and to treat or prevent infections with Candida in newborns, respectively. These drugs were introduced and used in clinical practice without sufficient knowledge, especially on appropriate dosing for this subpopulation. For caffeine and ibuprofen we found that the clearance rapidly increases with postnatal age, while for fluconazole clearance is better reflected by body weight and serum creatinine. For these drugs dosing guidelines were proposed based on identified covariates for their pharmacokinetics. Ibuprofen therapy was further investigated by examining the course of spontaneous closure of the ductus arteriosus, and evaluating the effects of ibuprofen exposure and patient characteristics simultaneously. Show less
The circadian timing system is highly integrated with the sleep-wake regulation system. This thesis focuses on how different pharmacological treatments influence the sleep regulation system and the... Show moreThe circadian timing system is highly integrated with the sleep-wake regulation system. This thesis focuses on how different pharmacological treatments influence the sleep regulation system and the circadian timing rhythm in two murine models. In the first animal model, which is presented in Chapter 2 and 3, we implanted EEG/EMG electrodes in freely moving Brown Norway rats. We chose this rat strain because it is pigmented and therefore a more representative model than the more mainstream rat strains which are usually albino rats. This study aimed to investigate the effect of caffeine, sleep deprivation and ketamine on sleep and circadian-controlled activity under constant darkness. In the second animal model, which is presented in Chapter 4 and 5, we implanted EEG/EMG or Multi-unit electrodes in chemotherapy-induced fatigue mice. All the results from this thesis and future perspectives were discussed in Chapter 6. We are able to see how disruption of sleep and the circadian clock adversely affect health and may contribute to many diseases in modern society. In this thesis, these studies provide a better understanding of these drugs influence the circadian timing system and sleep-wake regulation and maybe new treatment approaches for antidepressant therapy and cancer related fatigue. Show less
As the number of patients suffering from dementia is still growing, most of the patients display behavioral symptoms at some time during the disease and these behavioral symptoms lower the quality... Show moreAs the number of patients suffering from dementia is still growing, most of the patients display behavioral symptoms at some time during the disease and these behavioral symptoms lower the quality of life and increase the burden of caregivers, adequate management of these symptoms is warranted. However, the etiology and management of behavioral symptoms is complex, resulting in (mis)use of pharmacological interventions: a cure which is often worse than the disease. In healthy adults, caffeine is known to influence behavior. Four different studies were conducted to see if caffeine is an easy to adjust cause or a pragmatic intervention for behavioral symptoms in patients with dementia. Based on these studies, we conclude caffeine can influence behavior in persons with dementia, but most likely not in all persons, not in all situations and not all of the time; but it can have an influence. In clinical practice it is advisable to consider caffeine as a possible moderator in the clinical assessment of behavioral symptoms in persons with dementia. Show less
Several factors that modulate migraine, a common primary headache disorder, also affect susceptibility to cortical spreading depolarization (CSD). CSD is a wave of neuronal and glial depolarization... Show moreSeveral factors that modulate migraine, a common primary headache disorder, also affect susceptibility to cortical spreading depolarization (CSD). CSD is a wave of neuronal and glial depolarization and thought to underlie the migraine aura and possibly headache. Here, we tested whether caffeine, known to alleviate or trigger headache after acute exposure or chronic use/withdrawal, respectively, modulates CSD. We injected C57BL/6J mice with caffeine (30, 60, or 120 mg/kg; i.p.) once (acute) or twice per day for one or two weeks (chronic). Susceptibility to CSD was evaluated by measuring the electrical CSD threshold and by assessing KCl-induced CSD. Simultaneous laser Doppler flowmetry was used to assess CSD-induced cortical blood flow changes. Recordings were performed 15 min after caffeine/vehicle administration, or 24 h after the last dose of chronic caffeine in the withdrawal group. The latter paradigm was also tested in mice carrying the familial hemiplegic migraine type 1 R192Q missense mutation, considered a valid migraine model. Neither acute/chronic administration nor withdrawal of caffeine affected CSD susceptibility or related cortical blood flow changes, either in WT or R192Q mice. Hence, adverse or beneficial effects of caffeine on headache seem unrelated to CSD pathophysiology, consistent with the non-migrainous clinical presentation of caffeine-related headache. Show less
Panagiotou, M.; Meijer, M.; Meijer, J.H.; Deboer, T. 2019
BackgroundSpontaneous EEG theta/beta ratio (TBR) probably marks prefrontal cortical (PFC) executive control, and its regulation of attentional threat-bias. Caffeine at moderate doses may strengthen... Show moreBackgroundSpontaneous EEG theta/beta ratio (TBR) probably marks prefrontal cortical (PFC) executive control, and its regulation of attentional threat-bias. Caffeine at moderate doses may strengthen executive control through increased PFC catecholamine action, dependent on basal PFC function.GoalTo test if caffeine affects threat-bias, moderated by baseline frontal TBR and trait-anxiety.MethodsA pictorial emotional Stroop task was used to assess threat-bias in forty female participants in a cross-over, double-blind study after placebo and 200 mg caffeine.ResultsAt baseline and after placebo, comparable relations were observed for negative pictures: high TBR was related to low threat-bias in low trait-anxious people. Caffeine had opposite effects on threat-bias in low trait-anxious people with low and high TBR.ConclusionsThis further supports TBR as a marker of executive control and highlights the importance of taking baseline executive function into consideration when studying effects of caffeine on executive functions. Show less
