Respiratory system caffeine, effects

Death from SNA Intoxication appears to Involve both cardiovascular and respiratory systems. 2 SNA Increases the effects of pentobarbital on both respiration and heart rate. The depressant effects of SNA on the myocardium and on the Purklnje system are antagonized effectively by epinephrine, but not by Metrazol (pentylenetetrazol) and caffeine. Artificial respiration restored cardiac stability and regularity. It was suggested that SNA Interferes with oxygen utilization In animals. The circulatory and respiratory responses to SNA were considered to be mediated through the medulla oblongata. 2... 

These three alkaloids are well-known compounds, as they are present in everyday foods and beverages, such as cocoa, drinking chocolate, tea, and cola, as well as in pharmaceutical products. In cocoa products, theobromine is the major alkaloid, followed by caffeine, which is found in small quantities. Slight traces of theophylline have been identified therefore, it is not considered relevant and is not reviewed in the cocoa products [22,23], The range of methylxanthines also depends on variables such as the origin of the cocoa beans, the fermentation process, and the cocoa production process. Thus, for instance, defatted cocoa beans may contain about 4% and 0.2% of theobromine and caffeine, respectively [24], Regarding their physiological effects in humans, methylxanthines have been related to various body systems, mainly the central nervous system, but also the cardiovascular, renal, and respiratory systems [25,26],... 

The effects of cisapride 0.2 mg/kg tds on acid gastroesophageal reflux in 32 formerly preterm infants receiving respiratory stimulation with caffeine have been stndied using 24-hour esophageal pH monitoring (27). Cisapride significantly reduced the reflux index and the freqnency of reflnx without impairing the systemic availability or therapentic effects of caffeine. 

Caffeine is a stimulant of the central nervous system. It eliminates fatigue and drowsiness. However, high doses cause gastrointestinal motility, restlessness, sleeplessness, nervousness, and tremor. Acute poisoning effects include nausea, vomiting, headache, excitability, tremor, and sometimes, convulsive coma. Other symptoms may be respiratory depression, muscle contraction, distorted perception, and hallucination. Ingestion of 15-20 g may be fatal to humans. 

Besides coffee and cola drinks, other sources of caffeine are tea, chocolate, and cocoa. Caffeine is a mild stimulant of the respiratory and central nervous systems, the reason for its well-known side effects of nervousness and insomnia. These characteristics, together with its behavior as a mild diuretic, account for the use of caffeine in a wide variety of products, including pain relievers, cold remedies, diet pills, and stay-awake pills (No-Doz ). Because caffeine is considered to be a drug, pregnant women should be prudent about how much caffeine they consume. Like most other drugs, caffeine enters the bloodstream, crosses the placental barrier, and reaches the fetus. 

Xanthine derivatives have a number of pharmacological properties in common. Five major actions are observed (1) central nervous system and respiratory stimulation, (2) skeletal muscle stimulation, (3) diuresis, (4) cardiac stimulation, and (5) smooth-muscle relaxation. Caffeine (29) increases central nervous system activity and its main effect is on the cerebral cortex, where it acts to produce clear thought and reduce drowsiness and fatigue. The normal dose is 100-200 mg (Cordell, 1981). The oral LD50 in mouse is 127-137 mg/kg the oral LD50 in rat for theobromine (31) is 950... 

The phosphodiesterase which cleaves cyclic AMP to adenylate is found in both particulate and soluble fractions of tissue homogenates, and it is inhibited by pyrophosphate and ATP, as well as by caffeine, theophylline, and theobromine. These three methylated xanthines cause central nervous system and respiratory stimulation, smooth muscle relaxation, diuresis, coronary dilatation, cardiac stimulation, and skeletal muscle stimulation these effects are believed to be due to increased tissue concentrations of cyclic AMP resulting from inhibition of phosphodiesterase activity. 

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