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wikitox:2.1.11.4.6_xanthines [2018/09/01 09:00] (current) |
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+ | Link to [[:wikitox:problems_for_discussion_2_xanthines|Problems for Discussion]] | ||
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+ | ---- | ||
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+ | ====== Xanthines ====== | ||
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+ | There are three main xanthine derivatives. Theophylline and aminophylline are methylxanthines once widely used for the treatment of asthma, but now less commonly so. Caffeine is a trimethylxanthine closely related to theophylline. And theobromine, which is a plant extract. | ||
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+ | The exact mechanism of toxicity is not known. | ||
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+ | **Theophylline** | ||
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+ | * inhibits phosphodiesterase at high levels, increasing intracellular cyclic adenosine monophosphate (cAMP). | ||
+ | * releases endogenous catecholamines | ||
+ | * stimulates beta-adrenergic receptors. | ||
+ | * And is an antagonist of adenosine receptors. | ||
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+ | **Caffeine** | ||
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+ | * acts primarily through inhibition of the adenosine receptor. | ||
+ | * In addition, with overdose there is beta-1 and beta-2 adrenergic stimulation secondary to release of endogenous catecholamines. | ||
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+ | ===== REFERENCES ===== | ||
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+ | Shannon M, Amitai Y, Lovejoy FH Jr. Multiple dose activated charcoal for theophylline poisoning in young infants. Pediatrics 1987;80(3):368-70 [[https://www.ncbi.nlm.nih.gov/pubmed/3627887|PMID3627887]] \\ | ||
+ | Henderson A, Wright DM, Pond SM. Management of theophylline overdose patients in the intensive care unit. Anaesth Intensive Care 1992;20(1):56-62 [[https://www.ncbi.nlm.nih.gov/pubmed/1609943|PMID1609943]] | ||
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