Adverse reactions to dipyridamole in patients undergoing stress/rest cardiac perfusion testing.

OBJECTIVE A reaction scale was used to assess noncardiac adverse reactions exhibited by nuclear medicine outpatients receiving intravenous dipyridamole for pharmacological stress testing. METHODS The study included 933 patients referred to 2 cardiac outpatient centers for assessment. All patients evaluated in this study were unable to perform treadmill stress testing and underwent pharmacological intravenous dipyridamole stress testing. Dual-isotope (201)Tl rest/(99m)Tc-sestamibi stress imaging was performed. An analysis of adverse reactions exhibited by patients given dipyridamole was tabulated. RESULTS Of the 933 patients, 520 (55.7%) demonstrated no adverse reaction to intravenous dipyridamole; 413 patients (44.3%) had adverse reactions of some type. Many of these patients had multiple types of reactions, and a total of 604 reactions were recorded. The most prevalent adverse reaction was headache (224 reactions; 37.1%), followed by chest pain (73 reactions; 12.1%), and nausea (67 reactions; 11.1%). A sex comparison revealed 271 of 454 male patients (59.7%) and 249 of 479 female patients (52%) demonstrated no adverse reaction to intravenous dipyridamole. An evaluation of the most prevalent adverse reaction (headache) demonstrated a significant difference between males (37.9%) and females (62.1%). CONCLUSION An adverse reaction scale characterizing common noncardiac side effects of dipyridamole in nuclear medicine cardiac patients demonstrated the most prevalent adverse reaction was headache. Analysis by sex revealed that significantly more females than males complained of headaches.