Fingolimod initiation results in decreased heart rate and may prolong the QT interval; fingolimod has not been studied in patients treated with drugs that prolong the QT interval, but drugs that prolong the QT interval have been associated with cases of TdP in patients with bradycardia. Concomitant use may increase the risk for QT prolongation.
Flecainide: (Major) Avoid coadministration of ribociclib with flecainide due to an increased risk for QT prolongation and torsade de pointes (TdP). Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Flecainide is a Class IC antiarrhythmic associated with a possible risk for QT prolongation and/or TdP; flecainide increases the QT interval, but largely due to prolongation of the QRS interval. Concomitant use may increase the risk for QT prolongation.
Flibanserin: (Severe) The concomitant use of flibanserin and moderate CYP3A4 inhibitors such as ribociclib is contraindicated. Moderate CYP3A4 inhibitors can increase flibanserin concentrations, which can cause severe hypotension and syncope. If initiating flibanserin following the use of ribociclib, start flibanserin at least 2 weeks after the last dose of ribociclib. If initiating ribociclib following flibanserin use, begin therapy at least 2 days after the last dose of flibanserin. In cases where the benefit of initiating ribociclib therapy within 2 days of stopping flibanserin clearly outweighs the risk of flibanserin-related hypotension and syncope, monitor the patient for signs of hypotension and syncope.
Fluconazole: (Severe) The concurrent use of fluconazole with drugs that are associated with QT prolongation and are CYP3A4 substrates, such as ribociclib, is contraindicated. Fluconazole has been associated with QT prolongation. 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; fluconazole also prolongs the QT interval. Concomitant use may increase the risk for QT prolongation. Ribociclib is also extensively metabolized by CYP3A4 and fluconazole is a moderate CYP3A4 inhibitor.
Fluoxetine: (Major) Avoid coadministration of ribociclib with fluoxetine 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; QT prolongation and TdP have been reported in patients treated with fluoxetine. Concomitant use may increase the risk for QT prolongation. Ribociclib is also extensively metabolized by CYP3A4; while fluoxetine is a weak inhibitor of CYP3A4, its metabolite norfluoxetine is a moderate CYP3A4 inhibitor.
Fluoxetine; Olanzapine: (Major) Avoid coadministration of ribociclib with fluoxetine 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; QT prolongation and TdP have been reported in patients treated with fluoxetine. Concomitant use may incr |
