Link to [[:wikitox:problems_for_discussion_2_xanthines|Problems for Discussion]]

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====== Xanthines ======

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.

The exact mechanism of toxicity is not known.

**Theophylline**

   * 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.

**Caffeine**

  * 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.

===== REFERENCES =====

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]]