Drug General Information (ID: DDITHJAPRQ)
Drug Name			Caffeine		Drug Info		Adenosine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antihypertensive Agents				Antiarrhythmic Agents
Structure

Mechanism of Caffeine-Adenosine Interaction (Severity Level: Moderate)
Attenuated pharmacological effects (Unspecific) Click to Show/Hide Mechanism Graph
Drug Name		Caffeine				Adenosine
Mechanism		Reduce therapeutic efficacy of adenosine receptor agonists by competitive antagonism of adenosine receptors				Adenosine receptor agonists
Key Mechanism Factor 1
		Factor Name		Pharmacodynamics
		Factor Description		Reduced pharmacological effects leading to insufficient efficacy and/or treatment failure.
Mechanism Description		Attenuated pharmacological effects of  Caffeine when combined with Adenosine

Recommended Action
Management		Clinicians should be aware that adenosine and other adenosine receptor agonists may be less effective in the presence of methylxanthines. Methylxanthines including caffeine should be withheld for 12 to 24 hours (or five half-lives) prior to administration of adenosine receptor agonists for myocardial perfusion imaging. However, parenteral aminophylline should be readily available for treating severe or persistent adverse reactions to adenosine receptor agonists such as bronchospasm or chest pain.

References
1	Product Information. Persantine (dipyridamole). Boehringer-Ingelheim, Ridgefield, CT.
2	Ranhosky A, Kempthorne-Rawson J, the Intravenous Dipyridamole Thallium Imaging Study Group "The safety of intravenous dipyridamole thallium myocardial perfusion imaging." Circulation 81 (1990): 1205-9. [PMID: 2107985]
3	Smits P, Schouten J, Thien T "Respiratory stimulant effects of adenosine in man after caffeine and enprofylline." Br J Clin Pharmacol 24 (1987): 816-9. [PMID: 3440102]