Recurrent psychotic episodes in a patient who received rituximab for the treatment of non-Hodgkin's lymphoma.

375 mg/m 2 for relapsed non-Hodgkin’s lymphoma (NHL). Ibuprofen and chlorpheniramine were administered prophylactically. Allergic reactions were moderate. Attending nurses noticed verbomania and hyperactivity 8 h after starting rituximab. He put off his clothes, walked around the ward and talked to medical staffs in an aggressive tone. He was uncooperative, combative, manic, insomniac and disjointed. The mentalstatus was assessed as grade 3 regarding insomnia, irritability and mood alteration. 2 They lasted in the two following days. Intensive examination revealed no neurological abnormalities. At the second administration, the mental disorders recurred. While uncooperative and combative attitudes were mild, he became manic and verbomanic. He was insomniac throughout the night. At the third administration, he was slightly irritated. The irritability was assessed as grade 1. Thereafter, these mental disorders never occurred throughout his clinical courses. NHL is in partialremission and his psychiatric status is normalin Jul y 2001. It is controversialas to whether monocl onalantibodies penetrate the blood–brain barrier. However, this case suggests that peripherally administered rituximab might influence the central nervous system (CNS). These findings are comparable to previous reports, in which systemically infused rituximab was active in CNS despite its concentration of only 2% of the corresponding blood concentrations. 3 The exact mechanisms of these complications remain unknown. Rituximab might promote cytokine release, leading to the development of mentaldisorders. The psychotic disorders might be ampl ified by the concurrent administration of nonsteroidalantiinflammatory drugs as reported in patients receiving other monoclonal antibodies, OKT3. 4 Or, the drug might react to proteins related to CD20 that were expressed in the nonlymphoid tissues including the brain. 5