Drug Interaction Report

GENERALLY AVOID: The use of cladribine with other immunosuppressive or myelosuppressive agents may increase the risk of infections. Cladribine alone may cause severe and prolonged myelosuppression, lymphopenia, and opportunistic infections. 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: Concomitant use of oral cladribine with immunosuppressive or myelosuppressive agents should be avoided if possible. Acute short-term therapy with corticosteroids can be administered. Caution is advised if IV cladribine 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. In patients who have previously been treated with immunomodulatory or immunosuppressive drugs, consider potential additive effect, mode of action, and duration of effect of the other drugs prior to initiation of cladribine. Patients should be advised to contact their physician if they develop signs and symptoms of infection such as fever, chills, diarrhea, sore throat, muscle aches, shortness of breath, blood in phlegm, weight loss, red or inflamed skin, body sores, and pain or burning during urination.

ADJUST DOSING INTERVAL: Oral cladribine may increase the bioavailability of other drugs, which may increase the risk or severity of adverse reactions. Cladribine tablets may contain hydroxypropyl betadex, which could form a complex with the active ingredients of other drugs, especially agents with low solubility. The clinical relevance of this interaction remains unknown.

MANAGEMENT: Administration of oral cladribine should be separated from any other oral drug by at least 3 hours.

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.