Drug Interaction Report

MONITOR: Coadministration with carboplatin or cisplatin may increase the systemic exposure of etoposide. The exact mechanism of interaction is unknown but may involve inhibition of etoposide metabolism. In one study, the median clearance of etoposide in 14 pediatric patients receiving concomitant therapy with high-dose carboplatin (400 to 700 mg/m2 given on alternate days of etoposide) was substantially lower than values previously reported in either children or adults. Higher etoposide concentrations were significantly associated with longer time to recovery of hematopoietic function. The interaction has also been reported with cisplatin during acute but not chronic administration.

MANAGEMENT: During concomitant therapy with carboplatin or cisplatin, patients should be observed for potentially increased toxicity of etoposide (e.g., myelosuppression, stomatitis, mucositis, alopecia, hepatotoxicity), and the dosage adjusted accordingly as necessary.