Possible Interaction: Caffeine and Vasodilator Agents

“The current American Society of Nuclear Cardiology (ASNC) imaging guidelines 5 recommend that caffeine and other methylxanthines (such as aminophylline or theobromine) be withheld for at least 12 hours prior to vasodilator stress MPI and list this as a contraindication for performing the test.”

“ Caffeine and theophylline block the vasodilating effects of adenosine and may act to enhance sympathoadrenal discharge and activate the renin‐angiotensin system.”

“For patients with peripheral arterial disease, drinking of caffeine-containing beverages may reduce the beneficial vasodilatory effect of elevated endogenous adenosine levels.”

“The increased production of a vasodilator such as PGI2 from blood vessels following exposure to caffeine may explain why caffeine has a beneficial effect in angina.”

“The clinical significance of this is that caffeine , a widely consumed adenosine receptor antagonist, could augment renin release responses to diseases such as renovascular hypertension, liver cirrhosis and heart failure and to therapeutic maneuvers such as salt restriction, diuretics and vasodilators.”

“Theophylline and caffeine (30- 100 mu M in arterial plasma) antagonized the vasodilatory effect of exogenous adenosine, abolished vasodilation due to EHNA+dipyridamole and reduced resting blood flow.”

“In summary, there is currently no robust evidence to reject the hypothesis that caffeine can have a negative impact on the diagnostic performance of vasodilatorMPS , especially at moderate to high concentrations.”

“It is therefore possible that caffeine intake may alter the sensitivity of vasodilator MPI in some patients.”

“Current American Society of Nuclear Cardiology guidelines recommend that caffeine be withheld for at least 12 hours prior to vasodilator stress MPI and lists caffeine intake in the previous 12 hours as a contraindication for performing adenosine, dipyridamole, or regadenoson MPI.”

“In line with the guidelines, we advise patients to withhold intake of any caffeinated products for 12 hours prior to undergoing vasodilator stress testing , but we do not cancel the test in patients who have had a cup of coffee in the morning prior to presenting to the laboratory.”