Adenosine caffeine interactions

In addition, adenosine is implicated in sleep regulation. During periods of extended wakefulness, extracellular adenosine levels rise as a result of metabolic activity in the brain, and this increase promotes sleepiness. During sleep, adenosine levels fall. Caffeine promotes wakefulness by blocking the interaction of extracellular adenosine with its neuronal receptors. ... 

Clark, R.L., Eschbach, K., Cusick, W.A. and Heyse, J.F. (1987). Interactions between caffeine and adenosine agonists in producing embryo resorptions and malformations in mice. Toxicol. Appl. Pharmacol. 91 371-385. 

Carter AJ, O Connor WT, Carter MJ, Ungerstedt U. (1995). Caffeine enhances acetylcholine release in the hippocampus in vivo by a selective interaction with adenosine A1 receptors. J Pharmacol Exp Ther. 273(2) 637-42. 

Changes in the activity of adenosine receptors have been implicated in the stimulant effects of drugs like caffeine. Carbamazepine exhibits a partial agonist effect on adenosine receptors, and experimental evidence suggests that the reduced reuptake and release of noradrenaline caused by the drug are due to its interaction with these receptors. The precise relevance of these findings to its anticonvulsant and psychotropic effects is presently unclear. 

CNS, smooth muscle T diuresis X- pit aggregation Available forms Daily t doses w/ max 3 g PO daily Contra Avoid in PRG lactation, CAD, hyperthyroidism, anxiety disorders d/t high, caffeine content Notes/SE Insomnia, tach, anxiety, N/V, HA, HTN, Sz Interactions T Effects OF anticoagulants, anti-pits, BBs, bron-choclilators T risk of hypertensive crisis W/ MAOIs T effects W/ cimetidine, ciprofloxacin, ephedrine, hormonal contraceptives, dieophylline, cola, coffee X-effects OF adenosine, antihypertensives, benzodiazepines, Fe, X- effects W/ smoking EMS Tinctures contain EtOH may exacerbate GI disorders HTN T effects of anticoagulants and BBs... 

Daly, JW, Dkena, D, Jacobson, KA, Analogues of adenosine, theophylline, and caffeine Selective interactions with A, and A, adenosine receptors. In Topics and perspectives in adenosine research (eds Gerlach, E and Backer, BF), Springer-Verlag, Heidelberg, 1987,23-36. 

Clinically important, potentially hazardous interactions with acetylcysteine, adenosine, aprepitant, aripiprazole, buprenorphine, caffeine, charcoal, clarithromycin, clobazam, dorazepate, clozapine, darunavir, dasatinib, delavirdine, dexamethasone, diltiazem, doxacurium, erythromycin, felodipine, fesoterodine, fosamprenavir, imatinib, influenza vaccines, lacosamide, lapatinib, levetiracetam, lopinavir, methylprednisolone, midazolam, nelfinavir, nilotinib, piracetam, prednisolone, propoxyphene, ritonavir, rivaroxaban, rufinamide, solifenacin, St John s wort, telithromycin, temsirolimus, terbinafine, tolvaptan, troleandomycin, verapamil, voriconazole... 

Several inhibitors are known that bind to the adenosine site of PARP (19). These inhibitors include 6-bromo-2 -deoxyuridine, caffeine, 5-bromouracil, diadenosine-tetraphosphate, 1-methyladenine, 5-nitrouracil, theophylline, theobromine, thymidine, and other compounds. These compounds are not as well studied as the nicotinamide analogs. In addition, it is not known whether these compounds can interact with the adenosine (A,) receptors that are involved in modulation of synaptic transmission and neuroprotective effects. 

There are some extremely complex interactions in this area. To follow just two examples The Aj activation of phospholipase C causes increased hydrolyis of inositol lipids so that inositol-1,4,5-trisphosphate is produced and can induce calcium release from microsomes. Caffeine can directly inhibit opening of the calcium channel in the microsomes beyond any action it may have on the initial Aj receptor [212, 213], Caffeine acting on hippocampal Ai receptors appears to stimulate release of acetylcholine, but it is actually blocking adenosine receptors that inhibit the release [214, 215]. The end-result is increased wakefulness produced by caffeine. 

Experimental studies in healthy subjects, on the way xanthine drugs possibly interact with adenosine, have shown that caffeine and theophylline (but not enprofylline) reduced the increased heart rate and the changes in blood pressure caused by infusions of adenosine, and attenuated adenosine-induced vasodilatation. Theophylline also attenuated adenosine-induced respiratory effects and chest pain. Similarly, an adenosine infusion antagonised the haemodynamic effects of a single dose of theophylline in healthy subjects, but did not reduce the metabolic effects (reductions in plasma potassium and magnesium). ... 

Caffeine, once in the bloodstream, interacts with nerve cells to block adenosine receptors. The result is an increase of dopamine and norepinephrine neurotransmitters. The effects of increased levels of these neurotransmitters are a feeUng of alertness, competence, and wakefulness. 

---