AI Insight
This study analyzed adverse event reporting databases to examine the relationship between fluoroquinolone antibiotics and tendon disorders, finding that levofloxacin showed the strongest and most consistent association with tendon injuries in Japanese patients. Among all fluoroquinolones studied, levofloxacin demonstrated particularly elevated risk in males aged 70 years and older, with most adverse events occurring within 14 days of starting the medication. Oral administration was associated with higher reporting rates than intravenous use.
Why it matters
These findings suggest that Japanese clinicians should exercise heightened caution when prescribing levofloxacin to elderly male patients, a demographic at substantially increased risk for tendon disorders. The identification of specific at-risk populations and the timing of adverse events can inform safer prescribing practices and early monitoring protocols.
Understand the Science
by Toshihisa Nakashima, Yoshihiro Noguchi, Rikuto Masuda, Tomoaki Yoshimura
This study evaluated the association between individual fluoroquinolones and tendon disorders in Japan using two spontaneous reporting systems: the Food and Drug Administration Adverse Event Reporting System (FAERS) and the Japanese Adverse Drug Event Report (JADER). Five agents—ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin, and ofloxacin—were analyzed for “Muscle, tendon and ligament injuries” and “Tendon disorders.” All fluoroquinolones showed positive signals in the FAERS, whereas only levofloxacin demonstrated consistent and robust associations in the Japanese subset of the FAERS and the JADER. In the JADER, levofloxacin exhibited strong signals for muscle, tendon, and ligament injuries (reporting odds ratio [ROR] 30.6, information component [IC] 4.5) and tendon disorders (ROR 134.2, IC 5.8). Stratified analysis revealed markedly stronger signals in males, particularly those aged ≥70 years (relative ROR 12.21 and 25.67; IC delta 3.18 and 2.85, respectively). Oral levofloxacin was associated with higher reporting odds than intravenous administration. Time-to-onset analysis indicated that most tendon-related adverse events occurred within 14 days after drug initiation. Levofloxacin exhibited the most consistent and robust association with tendon disorders, especially in males aged ≥70 years in Japan. Therefore, clinicians in Japan should exercise caution when prescribing levofloxacin to older male patients.