NCI Drug Dictionary

The NCI Drug Dictionary contains technical definitions and synonyms for drugs/agents used to treat patients with cancer or conditions related to cancer. Each drug entry includes links to check for clinical trials listed in NCI's List of Cancer Clinical Trials.

A naturally occurring xanthine derivative with central nervous system (CNS) stimulating activity. Due to the structural similarity to adenosine, caffeine binds to and blocks adenosine receptors, thereby preventing the inhibitory effects of adenosine on nerve cells. This leads to stimulation of medullary, vagal, vasomotor, and respiratory centers in the brain; and the release of epinephrine. Physiologic responses can include bradycardia, tachycardia, vasoconstriction, CNS excitablility, increased respiratory rate, increased blood pressure, increased blood flow to muscles, decreased blood flow to skin and inner organs, and release of glucose by the liver. Due to the interaction between adenosine A2A and dopamine D2 receptors, caffeine can also indirectly increase the levels of dopamine in the brain. Check for active clinical trials using this agent. (NCI Thesaurus)

Chemical structure:
  • 1,3,7-trimethylxanthine
  • 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione