Safety and tolerability of intravenous regadenoson in healthy subjects: A randomized, repeat-dose, placebo-controlled study

BACKGROUND Regadenoson is a selective A2A adenosine receptor agonist indicated for radionuclide myocardial perfusion imaging in patients unable to undergo adequate exercise stress. However, the safety, tolerability, and plasma concentrations associated with repeated doses have not previously been assessed. METHOD AND RESULTS Healthy males and females were randomized to receive intravenous regadenoson [100 μg (3 doses), 200 μg (3 doses), or 400 μg (2 doses)], or placebo (2 or 3 doses; 0.9% sodium chloride); all doses 10 minutes apart. The primary endpoint was vital sign measurements (blood pressure and heart rate). Secondary endpoints included 12-lead electrocardiogram measurements, clinical laboratory evaluations (hematology, chemistry, and urinalysis), and adverse events. Thirty-six subjects were randomized and completed the study. Plasma concentrations of regadenoson increased in a dose-related manner and with successive doses. No consistent effect was observed for systolic blood pressure, although diastolic blood pressure was slightly lower than placebo for all regadenoson groups. Transient, dose-dependent increases in heart rate were observed in all regadenoson groups. There were no serious adverse events; 27 adverse events occurred in 14 regadenoson-treated subjects vs two events in two placebo-treated subjects. CONCLUSION Repeated doses of regadenoson appeared to be safe and well tolerated in healthy subjects.