Ribociclib may prolong the QT interval and increase the risk of cardiac arrhythmia.
Use with caution in patients with a congenital long QT syndrome, patients treated with a high cumulative dose of anthracycline therapy, patients taking medications that may prolong the QT interval, and those with electrolyte disturbances.
Risk factors (e.g. electrolyte abnormalities) should be corrected, where possible, prior to commencement of treatment and the concurrent use of drugs that may prolong the QT interval should be avoided.
Check serum electrolytes (including potassium, calcium, phosphate and magnesium) at baseline, prior to cycles 2 to 6 and as clinically indicated. Perform electrocardiogram (ECG) at baseline, on day 14 of cycle 1, prior to cycle 2 and as clinically indicated.