The pharmacokinetics of caffeine and its dimethylxanthine metabolites in patients with chronic liver disease.

Scott, NR; Stambuk, Drago; Chakraborty, J.; Marks, Vincent; Morgan, MY

doi:10.1111/j.1365-2125.1989.tb05352.x

Cited by 39 publications

(24 citation statements)

References 21 publications

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“…The childpugh classification adopted in the present study is also similar to that used by N.R. Scott et al 15 in 1989, their study also showed a significant correlation (p < 0.001) between childpugh score of severity of liver disease and salivary caffeine clearance values. It is also evident from the results that salivary caffeine concentration in patients (study group) at 0 h, i.e.…”

Section: Discussionsupporting

confidence: 84%

“…1,5 However saliva is emerging as efficient and feasible diagnostic fluid for many diseases and also being popular among patients and clinicians due to easy collection and less chances of cross contamination and can be used as sample for the study of larger group like country surveys. Saliva has been proposed as suitable diagnostic fluid for caffeine clearance assessment which is substantiated by a number of studies that confirmed an excellent correlation between caffeine elimination in saliva and liver function 14,15,16 In spite of these encouraging studies, the caffeine clearance test from saliva sample is not popular in clinical practice. This warrants further study to assess its feasibility as non invasive diagnostic modality for quantitative assessment of liver function and find out the possible shortcomings which is hindering its popularity.…”

Section: 10mentioning

confidence: 99%

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The role of salivary caffeine clearance in the diagnosis of chronic liver disease

Tiwari

Patil

Khanna

et al. 2015

Journal of Oral Biology and Craniofacial Research

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EMIT Liver cirrhosis a b s t r a c tBackground: Chronic liver diseases (CLD) are quite prevalent throughout the globe. Its early and correct diagnosis is always a concern among physicians, especially the residual liver function. For this various substrates like caffeine are being investigated in body fluids like serum and saliva. Saliva as a study sample has its own advantages due to its non invasiveness; it can be very useful study sample.Methods: 30 Subjects with CLD and 15 healthy controls were administered 200 mg of caffeine. Subjects classified into severity groups (class-A-mild-n ¼ 9, B-moderate-n ¼ 11, and C-severe-n ¼ 10) based on "Child-pugh classification" of severity of liver disease. After 17 h of dietary caffeine restriction and before drug administration, 0 h salivary sample was taken. After the dose of caffeine, 4 and 16 h saliva sample was taken. Blood sample was taken from controls only at same time points. These samples were analyzed on semi automated analyzer using Enzyme Multiplied Immunoassay Technique (EMIT) by spectrophotometric method. Caffeine clearance values were calculated and results were statistically analyzed.Results: Significant correlation was found between serum caffeine clearance and salivary caffeine clearance (SCC). Controls showed higher mean of SCC value of 1.6 ± 0.2 ml/min/kg while SCC values of subjects were less, with mean of 0.5 ± 0.2 ml/min/kg. Significant correlation was found between degree of hepatic dysfunction and SCC values.Conclusion: Saliva can be used for diagnosis of CLD and assessment of residual liver function in CLD as alternative to serum.

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Section: Discussionsupporting

confidence: 84%

Section: 10mentioning

confidence: 99%

The role of salivary caffeine clearance in the diagnosis of chronic liver disease

Tiwari

Patil

Khanna

et al. 2015

Journal of Oral Biology and Craniofacial Research

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“…Participants were instructed not to eat or drink anything (with the exception of water) after 9:00 p.m. the night before a test session and not to use any over-the-counter medications or herbal supplements 24 h prior to testing. A 12-h abstinence period is thought to be a sufficient wash-out period to attenuate the effects of earlier caffeine consumption, given that the mean plasma and elimination half-life of caffeine ranges from 3 to 10 h (Blanchard and Sawers, 1983; Scott et al, 1989; Nehlig et al, 1992a). Test sessions began between 7:00 and 9:30 a.m.…”

Section: Methodsmentioning

confidence: 99%

Caffeine Promotes Global Spatial Processing in Habitual and Non-Habitual Caffeine Consumers

Giles

Mahoney

Brunyé

et al. 2013

Front. Hum. Neurosci.

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Information processing is generally biased toward global cues, often at the expense of local information. Equivocal extant data suggests that arousal states may accentuate either a local or global processing bias, at least partially dependent on the nature of the manipulation, task, and stimuli. To further differentiate the conditions responsible for such equivocal results we varied caffeine doses to alter physiological arousal states and measured their effect on tasks requiring the retrieval of local versus global spatial knowledge. In a double-blind, repeated-measures design, non-habitual (Experiment 1; N = 36, M = 42.5 ± 28.7 mg/day caffeine) and habitual (Experiment 2; N = 34, M = 579.5 ± 311.5 mg/day caffeine) caffeine consumers completed four test sessions corresponding to each of four caffeine doses (0, 100, 200, 400 mg). During each test session, participants consumed a capsule containing one of the three doses of caffeine or placebo, waited 60 min, and then completed two spatial tasks, one involving memorizing maps and one spatial descriptions. A spatial statement verification task tested local versus global spatial knowledge by differentially probing memory for proximal versus distal landmark relationships. On the map learning task, results indicated that caffeine enhanced memory for distal (i.e., global) compared to proximal (i.e., local) comparisons at 100 (marginal), 200, and 400 mg caffeine in non-habitual consumers, and marginally beginning at 200 mg caffeine in habitual consumers. On the spatial descriptions task, caffeine enhanced memory for distal compared to proximal comparisons beginning at 100 mg in non-habitual but not habitual consumers. We thus provide evidence that caffeine-induced physiological arousal amplifies global spatial processing biases, and these effects are at least partially driven by habitual caffeine consumption.

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“…Treatment order was counterbalanced across participants using a complete Latin square. Participants were tested during morning sessions following a 12 h fast, which is thought to be a sufficient wash-out period to attenuate the effects of earlier caffeine and theanine consumption, particularly given that the mean plasma elimination half-life ranges from 3 to 10 h in caffeine (Blanchard and Sawers 1983;Nehlig et al 1992;Scott et al 1989) and from 65 to 75 min in theanine (Scheid et al 2012;van der Pijl et al 2010). Participants were further instructed not to use any over-the-counter medications or herbal supplements for 24 h prior to testing.…”

Section: Designmentioning

confidence: 99%

Caffeine and theanine exert opposite effects on attention under emotional arousal

Giles

Mahoney

Brunyé

et al. 2017

Can. J. Physiol. Pharmacol.

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Tea is perceived as more relaxing than coffee, even though both contain caffeine. L-theanine in tea may account for the difference. Consumed together, caffeine and theanine exert similar cognitive effects to that of caffeine alone, but exert opposite effects on arousal, in that caffeine accentuates and theanine mitigates physiological and felt stress responses. We evaluated whether caffeine and theanine influenced cognition under emotional arousal. Using a double-blind, repeatedmeasures design, 36 participants received 4 treatments (200 mg caffeine + 0 mg theanine, 0 mg caffeine + 200 mg theanine, 200 mg caffeine + 200 mg theanine, 0 mg caffeine + 0 mg theanine) on separate days. Emotional arousal was induced by highly arousing negative film clips and pictures. Mood, salivary cortisol, and visual attention were evaluated. Caffeine accentuated global processing of visual attention on the hierarchical shape task (p < 0.05), theanine accentuated local processing (p < 0.05), and the combination did not differ from placebo. Caffeine reduced flanker conflict difference scores on the Attention Network Test (p < 0.05), theanine increased difference scores (p < 0.05), and the combination did not differ from placebo. Thus, under emotional arousal, caffeine and theanine exert opposite effects on certain attentional processes, but when consumed together, they counteract the effects of each other.Key words: caffeine, theanine, arousal, attention, cortisol, emotion, cognition.Résumé : Le thé est perçu comme étant plus relaxant que le café, même si tous deux contiennent de la caféine. La L-théanine du thé pourrait être à l'origine de la différence entre les deux. Consommées ensemble, la caféine et la théanine exercent des effets similaires sur les facultés cognitives que la caféine seule, mais elles exercent des effets contraires sur l'éveil : effets d'accentuation de la caféine et effets mitigés de la théanine sur le plan des réactions au stress de natures physiologique et des sensations. Nous avons tenté de vérifier l'hypothèse selon laquelle la caféine et la théanine pourraient influencer les facultés cognitives en situation d'excitation émotionnelle. À l'aide d'un modèle à double insu avec mesures répétées sur des jours distincts, nous avons administré les traitements suivants chez 36 participants : caféine à 200 mg + théanine à 0 mg, caféine à 0 mg + théanine à 200 mg, caféine à 200 mg + théanine à 200 mg et caféine à 0 mg + théanine à 0 mg. Nous avons provoqué une excitation émotionnelle à l'aide d'images et de séquences filmées négatives. Nous avons évalué l'humeur, les taux de cortisol dans la salive et l'attention visuelle. La caféine entraînait une accentuation du traitement global par l'attention visuelle aux tâches de catégorisation de formes (« hierarchical shape task »; p < 0,05), la théanine entraînait une accentuation du traitement local (p < 0,05), et l'association des deux donnait les mêmes résultats que le placebo. La caféine entraînait une réduction des scores de différence des conflits en présenc...

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The pharmacokinetics of caffeine and its dimethylxanthine metabolites in patients with chronic liver disease.

Cited by 39 publications

References 21 publications

The role of salivary caffeine clearance in the diagnosis of chronic liver disease

The role of salivary caffeine clearance in the diagnosis of chronic liver disease

Caffeine Promotes Global Spatial Processing in Habitual and Non-Habitual Caffeine Consumers

Caffeine and theanine exert opposite effects on attention under emotional arousal

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