Drug Interaction Report

MONITOR: The use of topotecan with other cytotoxic agents is likely to result in greater myelosuppression due to additive or synergistic pharmacologic effects. Severe neutropenia and neutropenic sepsis resulting in death were reported with topotecan and cisplatin.

MANAGEMENT: Caution is advised if topotecan is used with other cytotoxic agents. Dosage reductions may be required, and bone marrow function should be closely monitored. Patients should be advised to contact their physician if they develop signs and symptoms of myelosuppression such as pallor, dizziness, fatigue, lethargy, fainting, easy bruising or bleeding, or signs of infection such as fever, chills, sore throat, body aches, and other influenza-like symptoms.

ADJUST DOSING INTERVAL: Food may reduce the oral bioavailability of ixazomib. A food effect study found that administration of a single 4 mg dose of ixazomib with a high-fat meal decreased ixazomib peak plasma concentration (Cmax) by 69% and systemic exposure (AUC) by 28%.

MANAGEMENT: Ixazomib should be taken at least one hour before or two hours after eating. On days when both ixazomib and dexamethasone are administered, advise patients to separate dosing times, since dexamethasone should be taken with food while ixazomib should be taken on an empty stomach.