. . . "(eg, 18 mg IV) may be needed in patients taking theophylline or theobromine, or who consume large amounts of caffeine; smaller doses (eg, 3 mg IV) should be given to patients taking dipyridamole or carbamazepine, those with transplanted hearts, or when injecting via a central vein.Prior to injection, warn the patient about transient side effects from adenosine, including chest discomfort, dyspnea," .