Effects of recombinant human granulocyte colony-stimulating factor (filgrastim) on ECG parameters in neutropenic...

Human granulocyte colony-stimulating factor (G-CSF) is a haematopoietic hormone that promotes the growth, proliferation, differentiation and maturation of neutrophil precursors. Filgrastim is a recombinant human G-CSF. Myocardial infarction, atrial fibrillation and arrhythmia have been reported in several patients with malignancy receiving filgrastim, but a causal relationship with the drug has not been established. The purpose of this study was to investigate the changes in ECG parameters in neutropenic patients during treatment with filgrastim.

This was a single-centre, prospective study carried out in a hospital emergency room. Patients with neutropenia and malignancy who were required to receive filgrastim were eligible for the study. After a reference ECG had been obtained, filgrastim was administered to all patients at a dose of 5 microg/kg/day subcutaneously for 2 days. Follow-up ECGs were then obtained at 12-hourly intervals. Continuous telemetric monitoring was conducted throughout hospitalization.

Serial ECG parameters were compared in 102 patients. There were no statistically significant differences between baseline and follow-up ECG measurements of rhythm, P-wave duration, PR interval, QRS-wave duration, corrected QT (QTc) interval, ECG axis, premature supraventricular events, ventricular arrhythmia, R-wave progression, right bundle branch block or left bundle branch block. There was a significant reduction in mean heart rate in subsequent ECGs compared with baseline (p < 0.05).

This study did not demonstrate any ECG changes other than a significant reduction in mean heart rate in this selected population of neutropenic patients given 2 days' treatment with subcutaneous 5 microg/kg/day of filgrastim.