systemic exposure of ribociclib may be increased resulting in an increase in ribociclib-related adverse reactions (e.g., neutropenia, QT prolongation). Ribociclib is extensively metabolized by CYP3A4 and cimetidine is a weak CYP3A4 inhibitor.
Cinacalcet: (Moderate) Use caution if coadministration of ribociclib with cinacalcet is necessary, as the systemic exposure of cinacalcet may be increased resulting in an increase in treatment-related adverse reactions. Monitor iPTH and serum calcium concentrations; adjust the dose of cinacalcet if necessary. Ribociclib is a moderate CYP3A4 inhibitor and cinacalcet is a CYP3A4 substrate.
Ciprofloxacin: (Major) Avoid coadministration of ribociclib with ciprofloxacin due to an increased risk for QT prolongation and torsade de pointes (TdP). Additionally, the systemic exposure of ribociclib may be increased resulting in an increase in treatment-related adverse reactions (e.g., neutropenia, QT prolongation). Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Rare cases of QT prolongation and TdP have been reported with ciprofloxacin during postmarketing surveillance. Concomitant use may increase the risk for QT prolongation. Ribociclib is also extensively metabolized by CYP3A4 and ciprofloxacin is a moderate CYP3A4 inhibitor.
Cisapride: (Severe) Coadministration of ribociclib with cisapride is contraindicated due to an increased risk for QT prolongation and torsade de pointes (TdP). Systemic exposure of cisapride may also be increased with concomitant use. Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. QT prolongation and ventricular arrhythmias, including torsade de pointes (TdP) and death, have been reported with cisapride. Concomitant use may increase the risk for QT prolongation. Ribociclib is also a moderate CYP3A4 inhibitor and cisapride is a CYP3A4 substrate.
Citalopram: (Major) Avoid coadministration of ribociclib with citalopram due to an increased risk for QT prolongation. If concurrent therapy is considered essential, ECG monitoring is recommended. Both drugs have been shown to prolong the QT interval in a concentration-dependent manner. Concomitant use may increase the risk for QT prolongation.
Clarithromycin: (Major) Avoid coadministration of ribociclib with clarithromycin due to the potential for additive effects on the QT interval and significantly increased exposure to ribociclib; exposure to clarithromycin may also increase. If coadministration cannot be avoided, reduce the ribociclib dose to 400 mg once daily. If clarithromycin is discontinued, resume the previous ribociclib dose after at least 5 half-lives of clarithromycin. Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Clarithromycin has an established risk for QT prolongation and torsade de pointes (TdP). Concomitant use may increase the risk for QT prolongation. Ribociclib is extensively metabolized by CYP3A4 and is a moderate CYP3A4 inhibitor; clarithromycin is a strong CYP3A4 inhibitor and CYP3A4 substrate.
Clobazam: (Moderate) Use caution if coadministration of ribociclib with clobazam is necessary, as the systemic exposure of ribociclib may decrease, resulting in decreased efficacy. Ribociclib is extensively metabolized by CYP3A4 and clobazam is a weak CYP3A4 inducer.
Clomipramine: (Major) Avoid coadministration of ribociclib with clomipramine due to an increased risk f |
