Investigation of Adverse Drug Reactions in Bortezomib Therapy for Relapsed Multiple Myeloma

Bortezomib was approved in 2006 for use in patients with multiple myeloma. Although a high frequency of adverse drug reactions (ADRs) was reported in some clinical studies on bortezomib, little information is available on the time of occurrence of the ADRs. Therefore, we investigated the ADRs in 15 patients with relapsed multiple myeloma who received bortezomib alone or combined with dexamethasone, for 2 cycles. The ADRs with high frequencies were constipation (80.0%), leucopenia (73.3%), anemia (73.3%), fatigue (73.3%), peripheral neuropathy (66.7%) and thrombocytopenia (66.7%). The number of leukocytes decreased to the minimum on the 9th day and had recovered on the 14th day. The number of platelets decreased to the minimum on the 13th day, and had recovered on the 19th day. Gastrointestinal adverse reactions including constipation, diarrhea, nausea and vomiting were observed from the 5th day. Based on these results, we prepared a patient education sheet showing the times of occurrence of high frequency ADRs in the therapy schedule visually. This sheet should be useful in gaining the understanding of patients and their families regarding bortezomib therapy as well as enhancing its safety.