Methylxanthines

In the present volume of the Handbook of Experimental Pharmacology well known experts describe the actions of different xanthines with a focus on caffeine and theophylline. A special chapter is devoted to theobromine, an active component of chocolate, the actions of which are less well characterized. This book also presents the pharmacology of one xanthine derivative, propentofylline, as an example of a xanthine that has gone through extensive development for a novel therapeutic area.

This report from the Committee on Military Nutrition Research reviews the history of caffeine usage, the metabolism of caffeine, and its physiological effects. The effects of caffeine on physical performance, cognitive function and alertness, and alleviation of sleep deprivation impairments are discussed in light of recent scientific literature. The impact of caffeine consumption on various aspects of health, including cardiovascular disease, reproduction, bone mineral density, and fluid homeostasis are reviewed. The behavioral effects of caffeine are also discussed, including the effect of caffeine on reaction to stress, withdrawal effects, and detrimental effects of high intakes. The amounts of caffeine found to enhance vigilance and reaction time consistently are reviewed and recommendations are made with respect to amounts of caffeine appropriate for maintaining alertness of military personnel during field operations. Recommendations are also provided on the need for appropriate labeling of caffeine-containing supplements, and education of military personnel on the use of these supplements. A brief review of some alternatives to caffeine is also provided.

The first part of the report deals with occurrence of methylxanthines in foods, beverages, and medicines, and estimates of caffeine intake. In addition, a short review of the pharmacological and toxicological actions of caffeine is given. The second and main part of the report reviews available information from epidemiological studies on the potential health hazards to the human foetus associated with parental intake during pregnancy of caffeine and related methylxanthines in foods, beverages and medicines. The studied adverse effects are influence on fertility, spontaneous abortion, congenital malformation, pre-term delivery, foetal growth retardation, foetal behaviour and effects on neonates, infants and young children. The conclusion of the report demonstrates the need for limiting caffeine exposure during pregnancy. The Nordic Working Group on Food Toxicology and Risk Evaluation (NNT) recognizes that the human exposure to caffeine and related compounds causes a spectrum of pharmacological effects, for instance cardiovascular, renal, neurological and behavioural effects. The increasing use of caffeine and related methylxanthines in various foods and beverages consumed by children and adolescents cause concern. NNT recommends that a full hazard characterization of caffeine and related methylxanthines should be performed with the aim to reach a conclusion about the upper safe level of intake of these compounds.

This is a technically detailed state-of-the-art text on phosphodiesterase inhibition and the practical applications of theophylline and other phosphodiesterase inhibitors in asthma and chronic obstructive airways disease. It contains important new information on the mechanisms of drug action and on the inhibition of individual isoenzymes of the phosphodiesterase enzyme family as a potentially useful, safe, and non-toxic approach to asthma therapy.

Caffeine-found in tea, coffee, mate, cola beverages, cocoa, and chocolate products-is an integral part of the diet of many people. Caffeine answers questions for a broad range of readers interested in the effects beverages and foods containing this dietary methylxanthine have on human health, nutrition, and physiological functioning. The composition, processing, consumption, health effects, and epidemiological correlations of caffeine are examined in detail. It is often said that too much caffeine is "bad for you." How much is too much? Get the facts on consumption of caffeine-containing products with this authoritative text. Chapters 1 and 2 offer an introductory, concise overview of the chemistry and analysis of methylxanthines. In Chapters 3 through 8, each natural product-tea, coffee, mate, and cocoa and chocolate products-is described in terms of botany, cultivation, processing, composition, and consumption patterns. Consumption of caffeine is also examined in detail in Chapter 9. Chapter 10 provides an easy-to-read overview of the basic physiology and biochemistry of caffeine. The ergogenic, cognitive, and emotional effects of caffeine are discussed in Chapters 11 and 12. Chapters 13 through 16 deal with specific health effects-serum cholesterol, cancer and fibrocystic breast disease, calcium and bone health, and human reproduction. For physicians, nutritionists, other health professionals, food scientists, and everyone interested in the effects of caffeine on the human body, Caffeine is a convenient, single-source reference.

Coffee, tea, and chocolate are among the most frequently consumed products in the world. The pleasure that many experience from these edibles is accompanied by a range of favorable and adverse effects on the brain that have been the focus of a wealth of recent research. Coffee, Tea, Chocolate, and the Brain presents new information on the

Written in the award-winning Incredibly Easy! style, this book presents everything the nurse and nursing student needs to know about how drugs act and interact in the treatment of disease. The book focuses on mechanisms of drug action; details specific drugs by pharmacologic class; reviews the nursing process related to each drug category for all body systems, plus pain medications, anti-infective drugs, and cancer drugs; and highlights potentially dangerous interactions, including drug-herb interactions. This thoroughly updated Second edition includes the most current NANDA diagnoses. New chapters cover genitourinary drugs and drugs to treat fluid and electrolyte imbalances. Obesity drugs have been added to the gastrointestinal drugs chapter.

Reports the deliberations of a working group convened to evaluate the strength of evidence linking the drinking of coffee, tea, and mate to the development of human cancer. Separate evaluations are also provided for caffeine, theophylline theobromine and methylglyoxal, which are chemical constituents of coffee, tea, and several other popular beverages. The first and most extensive monograph evaluates the large number of studies designed to assess the carcinogenic potential of coffee. On the basis of available data, the working group concluded that coffee is possibly carcinogenic to the human urinary bladder. Evidence further suggests that coffee may actually protect humans against cancer of the colon and rectum. The risk for breast cancer was shown, with remarkable consistency, to have no association with coffee drinking. The second monograph evaluates the carcinogenicity of black and green teas. Although available data were judged inadequate to classify tea according to its carcinogenic risk, the analysis uncovered evidence suggesting that the temperature at which tea is drunk may be a more important determinant of risk than the chemical composition of the beverage. This observation is further supported in the monograph on mate, a South American beverage, which is usually drunk very hot following repeated addition of almost boiling water to the infusion. While mate could not be classified on the basis of available data, hot mate drinking was judged to have a probable association with the development of oesophageal and oral cancers. Evidence was inadequate to assess the carcinogenicity of caffeine, theophylline, theobromine, and methylglyoxal.