Quinolone Ear Drops and Achilles Tendon Rupture

Area of Science:

• Pharmacovigilance
• Otolaryngology
• Orthopedics

Background:

• Delayed eardrum healing in rats treated with otic quinolones (OQ) suggests potential systemic effects.
• Case reports link OQ treatment to tendinopathies, raising concerns about adverse events.

Purpose of the Study:

• To investigate the association between otic quinolone (OQ) exposure and tendon rupture outcomes.
• To compare the risk of Achilles tendon rupture (ATR), Achilles tendinitis (AT), and all-type tendon rupture (ATTR) following OQ treatment versus other otitis treatments.

Main Methods:

• A cohort study of 1,501,009 otitis episodes in patients aged 19-64.
• Utilized an active comparator, new-user design with propensity score weighting to balance groups.
• Follow-up included Achilles tendon rupture, tendinitis, and all tendon ruptures, with adjustments for potential confounders like physical activity.

Main Results:

• Otic quinolone exposure was associated with a significantly increased hazard ratio for Achilles tendon rupture (HR, 4.49) and all-type tendon rupture (HR, 1.71).
• Weighted risk differences indicated a higher incidence of ATR and ATTR per 100,000 episodes with OQ use.
• Analysis of clavicle fractures and sports injuries suggested limited residual confounding from physical activity differences.

Conclusions:

• Otic quinolone exposure may be linked to systemic adverse effects, including tendon injuries.
• Clinicians should be aware of and counsel patients on the potential risks associated with OQ treatment.
• Further research is warranted to elucidate the mechanisms and confirm these findings.