Machiko Tsukaguchi, Masaru Shibano, Ai Matsuura, Satoru Mukai

Peripheral neuropathy (PN) caused by bortezomib is an important complication of multiple myeloma. Subcutaneous injection of bortezomib reduced PN, but 24% of cases were grade 2 PN and 6% of cases were grade 3 PN. PN higher than grade 2 was not resolved by subcutaneous injection. PN higher than grade 3 has serious dose limiting toxicity and is the cause of discontinuing bortezomib treatment. Lafutidine is an H2-blocker with gastroprotective activity and is thought to function by increasing mucosal blood flow via capsaicin sensitive neurons. The same activity of lafutidine is considered to improve glossodynia and taxane induced PN. We hypothesized that lafutidine prevents or improves PN that is caused by bortezomib. In the current study, bortezomib was administered in the usual manner (intravenous administration of bortezomib 1.3 mg/m(2), twice a week for 2 weeks, followed by 1 week without treatment) for up to four cycles to compare our data with other studies. Lafutidine was administered orally at a dose of 10 mg twice daily. In our eight evaluated cases, the total occurrence of PN was four out of eight patients (50%). There were only grade 1 PN (4 out of 8) cases, and no cases higher than grade 2. We conclude that (1) the total occurrence of PN was not improved, (2) there was no PN after the first course, (3) there were only grade 1 cases and there were no cases higher than grade 2, and (4) no cases discontinued bortezomib treatment because of PN. This is the first report showing that lafutidine is useful for the amelioration of bortezomib induced PN.