ase in treatment-related adverse reactions. Ribociclib is a moderate CYP3A4 inhibitor and regorafenib is a CYP3A4 substrate.
Repaglinide: (Moderate) Use caution if coadministration of ribociclib with repaglinide is necessary, as the systemic exposure of repaglinide may be increased resulting in increase in treatment-related adverse reactions including hypoglycemia; adjust the dose of repaglinide if necessary. Ribociclib is a moderate CYP3A4 inhibitor and repaglinide is a CYP3A4 substrate.
Rifabutin: (Moderate) Use caution if ribociclib is coadministered with rifabutin, as the systemic exposure of rifabutin may increase resulting in rifabutin-related adverse reactions; adjust the dose of rifabutin if needed. Exposure to ribociclib may also decrease, resulting in reduced efficacy. Ribociclib is extensively metabolized by CYP3A4 and is a moderate CYP3A4 inhibitor; rifabutin is both a CYP3A4 substrate and inducer.
Rifampin: (Major) Avoid coadministration of ribociclib with rifampin; the systemic exposure of ribociclib was significantly decreased in a drug interaction study. Consider an alternative treatment with less potential to induce CYP3A. Ribociclib is a CYP3A4 substrate and rifampin is a strong CYP3A4 inducer. In a drug interaction study in healthy volunteers, the ribociclib AUC (0-inf) and Cmax values were decreased by 89% and 81%, respectively, when a single dose of ribociclib 600 mg was administered following 14 days of rifampicin 600 mg daily compared with a single dose of ribociclib administered alone.
Rifapentine: (Moderate) Use caution if coadministration of ribociclib with rifapentine is necessary, as the systemic exposure of ribociclib may be decreased resulting in decreased efficacy. Ribociclib is extensively metabolized by CYP3A4 and rifapentine is a moderate CYP3A4 inducer.
Rilpivirine: (Major) Avoid coadministration of ribociclib with rilpivirine due to an increased risk for QT prolongation. Systemic exposure of rilpivirine may also be increased resulting in increase in treatment-related adverse reactions. Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Supratherapeutic doses of rilpivirine (75 to 300 mg per day) have caused QT prolongation. Concomitant use may increase the risk for QT prolongation. Ribociclib is also a moderate CYP3A4 inhibitor and rilpivirine is a CYP3A4 substrate.
Risperidone: (Major) Avoid coadministration of ribociclib with risperidone due to an increased risk for QT prolongation and torsade de pointes (TdP). Systemic exposure of risperidone may also be increased resulting in increase in treatment-related adverse reactions. Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Risperidone has been associated with a possible risk for QT prolongation and/or TdP. Reports of QT prolongation and TdP during risperidone therapy are noted by the manufacturer, primarily in the overdose setting. Concomitant use may increase the risk for QT prolongation. Ribociclib is also a moderate CYP3A4 inhibitor and risperidone is a CYP3A4 substrate.
Ritonavir: (Severe) Coadministration of ribociclib with ritonavir is contraindicated, as elevated plasma concentrations of ribociclib may be associated with QT prolongation; exposure to ritonavir may also increase. Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Ritonavir has also been associated with QT prolongation. Ribociclib is al |
