Small cell lung cancer (SCLC) with ectopic adrenocorticotropic hormone (ACTH) syndrome and resultant hypercortisolism carries a poor prognosis with a short median survival and high incidence of infective complications. The combination of etoposide with either carboplatin or cisplatin is the current standard chemotherapy used for the management of SCLC. Etoposide is metabolised by cytochrome P450 3A4. Ketoconazole is an imidazole derivative possessing antifungal properties and also causes inhibition of adrenal corticosteroid and androgen production. There is an additional increased risk of toxicity due to a potential interaction between etoposide and ketoconazole, which is a strong inhibitor of cytochrome P450 3A4, and theoretically can lead to greater myelosuppression. Metyrapone can be a safe alternative in such settings.
