Q97) A 68 year old man with history of DM type II, Hypertension and severe osteoarthritis presents to your office with complaints of chest pain on exertion for past 3 months. He denies any pain now. He smokes about one pack cigarettes per day. His only medications are Glyburide, Metprolol, Enalapril and Metformin. An EKG is obtained in the office and it reveals non-specific ST segment changes. The patient is scheduled for Dipyridamole stress test . The patient should be advised regarding which of the following:
A) Avoid Aspirin or NSAID for 24 hours prior to testing
B) Stop Metprolol 24 hours prior to tesing
C) Avoid Coffee or Caffeine for 24 hours prior to testing
D) Avoid smoking for one week prior to testing
E) Start inhaled Albuterol two days prior to testing
Archer USMLE Step 3 Blog 
D
I think “Avoid caffeine” is the answer
c
C.Caffenine blocks Adenosine Receptors & blunt the vasodilators properties of Caffeine-From Archer Lecture
b
Answer is C. Patients using methylxanthines (eg, caffeine, aminophylline) should not undergo dipyridamole stress testing because these substances act as competitive inhibitors of dipyridamole at the receptor level, potentially decreasing or completely attenuating the vasodilatory effect of dipyridamole. In general, patients should refrain from ingesting caffeine for at least 24 hours prior to dipyridamole administration. Patients should avoid decaffeinated products, which typically contain some caffeine, as opposed to caffeine-free products, which do not.
http://emedicine.medscape.com/article/1827166-overview#aw2aab6b2b3
Answer = B.
stop B-blockers 24 hrs before the test just in case there is need to resuscitate the patient. B-blockers will blunt the effect of epinephrine.
answer is C check archer’s notes, caffeine is a competitive antagonist of di[yridamole receptors therefore would potentiate the vasodilatory response and increased risk of false positive results