electrocardiographic changes after granisetron administration for chemotherapy induced nausea and vomiting

cancer patient receive various cytotoxic drugs in association with antiemetic drugs such as 5ht3 receptor antagonists as their chemotherapy regimen. 5ht3 receptor antagonists have been reported to produce changes in ecg parameter. there are only a few studies about cardiovascular events of these drugs in patient receiving potentially cardiotoxic chemotherapies. the subject of this study is to evaluate ecg changes after administration of chemotherapeutic agents and granisetron (the most commonly used 5ht3 antagonist in iran) in adults with cancer. for this clinical trial study, all cancer patients referred to department of radiation oncology of imam hossein hospital since august 2005 to march 2006 were evaluated if they had inclusion criteria. granisetron (3 mg) was infused intravenously over 30 seconds just a few minutes before chemotherapeutic agent administration. the 12-lead ecg recording was obtained before and 90 minutes after infusion of granisetron. one cardiologist determined pr, qrs, qtc intervals and heart rate of all ecgs. during the study period 54 patients fulfilled our criteria. with paired t-test, the pr and qtc intervals, but not qrs interval showed statistically significant prolongation after drug infusion (p < 0.0001), and heart rate showed statistically significant decrease (p < 0.0001). the ecg findings of chemotherapeutic agents and granisetron administration were prolongation of pr and qtc intervals and decrease of heart rate (p < 0.0001). although these changes did not cause clinical signs, with keeping in mind that there may be possible drug-drug interactions and preexisting cardiac comorbidities in cancer patient, it seems reasonable and necessary to consider physical condition specifically cardiac condition and drug usage of each patient, while designing chemotherapy regimen and supportive drugs.