Paralytic ileus following "subcutaneous bortezomib" therapy: focus on the clinical emergency-report of two cases.

We retrospectively analyzed the medical history of 19 elderly myeloma patients treated with the "novel subcutaneous formulation of bortezomib." In our experience, two patients (10 %) discontinued treatment for paralytic ileus. The exact pathogenetic mechanisms of toxic megacolon and paralytic ileus due to "novel subcutaneous formulation of bortezomib" are unclear. Probably, it may be related to possible damage of the autonomic nerve fibers that control organ functions. Adequate prevention and management of the gastrointestinal (GI) toxicities with the use of fluid intake and prokinetic and laxative drugs (at least two types of agents in a suboptimal dose) especially in patients with risk factors for GI side effects (anti-myeloma novel agents, opioids or antiemetics, iron supplements, spinal and cord compression, immobility, history of constipation) can decrease the possibility of interruption of administration of drug and increase adherence to treatment. Clearly this complication must be borne in mind whenever a patient develops acute abdominal pain and distension.