Drug Interaction Report

MONITOR: The use of ustekinumab with other immunosuppressive or myelosuppressive agents may increase the risk of infections. Serious bacterial, fungal, and viral infections have been observed during clinical trials with ustekinumab, and the risk may theoretically increase when coadministered with other immunosuppressive therapy. Agents that may be significantly myelo- or immunosuppressive include antineoplastic agents, radiation, zidovudine, linezolid, some antirheumatic agents, high dosages of corticosteroids or adrenocorticotropic agents (greater than 10 mg/day to 1 mg/kg/day, whichever is less, of prednisone or equivalent for more than 2 weeks), and long-term topical or inhaled corticosteroids.

MANAGEMENT: Caution is advised if ustekinumab must be used in patients who have recently received or are receiving treatment with other immunosuppressive or myelosuppressive drugs, and vice versa. Close clinical and laboratory monitoring for the development of severe hematologic adverse effects is recommended both during and after discontinuation of therapy.

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.