Detection of fluoroquinolone-induced tendon disorders using a hospital database in Japan

Tendinitis and tendon rupture are well-known side effects of fluoroquinolones (FQs) in Western countries. In Japan, some case reports have been reported; however, the incidence of FQ-induced tendon disorders has not been investigated. The aims of this study were to measure the occurrence of tendon disorders associated with FQs in Japanese patients and to compare the observed risk with that of previous reports. Moreover, the observed risk in FQ-prescribed patients was compared with that in cephalosporin-prescribed patients.

The Hamamatsu University Hospital database was examined to determine the risk of tendon disorders that occurred in all inpatients and outpatients between the first day of prescription of an oral FQ or cephalosporins to the calculated end date plus 30 days. The risk of tendon disorders, the risk ratio, and their 95% confidence intervals (CIs) were evaluated.

From April 1996 to December 2009, FQs were prescribed to 17 147 patients, 14 of whom had tendon disorders (risk: 0.082%, 95%CI: 0.049-0.137). The risk of a tendon disorder in FQ-prescribed patients was significantly higher than that in cephalosporin-prescribed patients (five tendon disorders in 38 517 patients, risk: 0.013%, 95%CI: 0.006-0.030, and p < 0.001). The risk ratio of a tendon disorder in FQ-prescribed patients in relation to cephalosporin-prescribed patients was 6.29 (95%CI: 2.27-17.46). A large discrepancy in the risk of tendon disorders was not observed between our findings and previous reports.

A hospital database search revealed that the risk of tendon disorders in Japanese patients administered with FQs was higher than in those administered with cephalosporins.