Drug Interactions between fluticasone / salmeterol and omacetaxine

MONITOR: The use of omacetaxine with other immunosuppressive or myelosuppressive agents may increase the risk of infections. Omacetaxine alone may cause severe myelosuppression, neutropenia, lymphopenia, and opportunistic infections. In clinical trials, infections/infestations (bacterial, viral, fungal, and nonspecified) were reported in up to 56% of patients, and grade 3 or 4 infections/infestations in up to 20% of patients. The risk may theoretically increase when coadministered with other hematotoxic 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 omacetaxine 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. Patients should be advised to seek medical attention if they experience symptoms such as fever, chills, shortness of breath, fatigue, and any unusual bleeding or bruising.

Although they are often combined in clinical practice, the concomitant use of beta-2 adrenergic agonists and corticosteroids may result in additive hypokalemic effects. Since beta-2 agonists can sometimes cause QT interval prolongation, the development of hypokalemia may potentiate the risk of ventricular arrhythmias including torsade de pointes. However, clinical data are limited, and the potential significance is unknown. Patients who are receiving systemic or nebulized formulations of beta-2 agonists, high dosages of inhaled beta-2 agonists, or systemic corticosteroid therapy may be at a greater risk of developing hypokalemia.