Caffeine acute effects

Smith, B., Rafferty, J., Lindgren, K., Smith, D. and Nespor, A., Chronic and acute effects of caffeine Testing a biobehavorial model. Physiol Behav, 51, 131-137, 1991. 

Elkins, R., Rapoport, J. and Zahn, T., Acute effects of caffeine in prepubertal... 

Van Soeren, M., Mohr, T., Kjaer, M. and Graham, T., Acute effects of caffeine ingestion at rest in humans with impaired epinephrine responses. J Appl Physiol 80(3), 999 1005, 1996. 

Massey, L. K., Hollingberry, P. W., Acute effects of dietary caffeine and sucrose on urinary mineral excretion of healthy adolescents, Nutrition Research, 8, 1005, 1988. 

Lorist MM, Snel J, Kok A, Mulder G. (1996). Acute effects of caffeine on selective attention and visual search processes. Psychophysiology. 33(4) 354-61. 

Un, acute exacerbation of chronic bronchitis prophylaxis in transurethral procedures Action Quinolone antibiotic -1- DNA gyrase. Dose 400 mg/d PO X w/ renal insuff, avoid antacids Caution [C, —] Interactions w/ cation-containing products Contra Quinolone all gy, children <18 y,T QT interval, X Disp Tabs SE NA/ /D, abd pain, photosens, Szs, HA, dizziness, tendon rupture, periph al neuropathy, pseudomembranous cohtis, anaphylaxis Interactions t Effects W/ cimetidine, probenecid T effects OF cyclosporine, warfarin, caffeine X effects W/ antacids EMS Monitor ECG for TqT int val, esp in pts taking class lA/III antiarrhythmics monitor ECG and BP for signs of h5 povolemia and electrol5rte disturbances (hypokalemia) d/t D T risk of photosensitivity Rxns OD May cause NA /D, confusion and Szs symptomatic and supportive... 

Acute Toxic Effects of Caffeine Chronic Effects of Caffeine Use Therapeutic Uses of Caffeine Conclusions Summary... 

The acute effects of caffeine include diuresis, stimulation of the heart and CNS, relaxation of smooth muscles, and stimulation of gastric acid. 

T Caffeine s acute effects of mood elevation and overall improvement in task performance seem to be reinforcing to humans. 

Because the physiological and pharmacological properties of caffeine represent the cumulative effects of not only the parent compound but also its metabolites, it is quite possible that effects attributed to caffeine per se are in fact mediated by one or more of its metabolites. It must also be noted that most of the knowledge about caffeine s effects has been derived from acute administration to fasted subjects submitted to a period of caffeine abstinence in order to ensure low plasma caffeine concentrations. It is thus difficult to extrapolate the results to the usual pattern of caffeine consumption in which... 

Pentoxifylline is stmcturaHy related to other methylxanthine derivatives such as caffeine [58-02-2] (1,3,7-trimethylxanthine), theobromine [83-67-0] (3,7-dimethylxanthine), and theophylline [58-55-9] (3,7-dihydro-1,3-dimethyl-1 H-piirine-2,6-dione or 1,3-dimethylxanthine), which also show radioprotective activity in some instances, suggesting that methylxanthines as a dmg class may radioprotect through a common mechanism (see Alkaloids). In a retrospective analysis of cervical and endometrial cancer patients receiving primary or adjuvant XRT, no association between caffeine consumption and incidence of acute radiation effects has been found. However, there was a decreased incidence of severe late radiation injury in cervical cancer patients who consumed higher levels of caffeine at the time of thek XRT (121). The observed lack of correlation between caffeine consumption and acute radiation effects is consistent with laboratory investigations using pentoxifylline. 

Human functioning the dual-interaction model. (From Smith, B.D., Effects of acute and habitual caffeine ingestion in physiology and behavior Tests of a biobehavioral arousal theory. Special issue Caffeine Research, Pharmacopsychoecologia, 7(2), 151-167, 1994. With permission.)... 

Moderate levels of chronic use of caffeine and other arousal agents tend to reduce the effects of acute exposure. However, higher chronic levels can exacerbate the impact of acute exposure. 

The individual s average habitual exposure to caffeine moderates the effect of acute exposure on both physiological and psychological functioning. 

There does, however, appear to be a ceiling on the acute dosage of caffeine that will enhance reaction time. At relatively low doses given prior to simple tasks or highly practiced complex tasks, the drug does enhance RT.41 104-117-143-144 However, these results may not apply to more complex tasks that have not been extensively practiced. For example, Lieberman79 found that 64 mg of caffeine decreased RT on a simple visual task in which the subject had to identify an object. However, the same dose of caffeine had no effect on RT when the subject had to choose objects in a more complex task. In fact, caffeine has been found to have detrimental effects on reaction times in some complex tasks.51 104 145 Again, there appears to be an inverted-U relationship between overall arousal — induced by the combination of caffeine and other arousal factors — and performance on reaction time tasks. 

As we noted earlier, caffeine affects not only arousal, but also other behavioral influences such as attentional focus. However, it now appears that these other effects may be secondary to the impact of the drug on arousal and that a multi-factorial model incorporating the inverted-U function may best describe that relationship. Most results in the literature to date are supportive of the biobehavioral model proposed here. However, research on the psychological effects of acute and habitual caffeine... 

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