Positive Association Between Fluoroquinolone Exposure and Tendon Disorders: A Nationwide Population-Based Cohort Study in Taiwan

Safety of fluoroquinolones

Fluoroquinolones (FQs) are one of the most commonly prescribed classes of antibiotics. Although they were initially well tolerated in randomized clinical trials, subsequent epidemiological studies have reported an increased risk of threatening, severe, long-lasting, disabling and irreversible adverse effects (AEs), related to neurotoxicity and collagen degradation, such as tendonitis, Achilles tendon rupture, aortic aneurysm, and retinal detachment. This article reviews the main potentially threatening AEs, the alarms issued by regulatory agencies and therapeutic alternatives.

Risk of Tendon Injury in Patients Treated With Fluoroquinolone (FQ) Versus Non-Fluoroquinolone Antibiotics for Community-Acquired Pneumonia (CAP)

BACKGROUND

Fluoroquinolones (FQs) are associated with increased risk of tendon injury but comparative risk versus other antibiotic options for the same indication has yet to be evaluated.

OBJECTIVE

Describe the incidence (relative risk) of any tendon injury in patients receiving FQ compared with other (non-FQs) antibiotics for treatment of community-acquired pneumonia (CAP).

METHODS

A retrospective propensity score weighted cohort study was performed to evaluate the association between FQ antibiotics and tendon injury risk at 2 time points (within 1 month and within 6 months of use) compared with non-FQ regimens for treatment of CAP. The evaluation was performed using the CCAE (MarketScan Commercial Claims and Encounters) and COB (Medicare Supplemental and Coordination of Benefits) databases from 2014 to 2020. Patients with ICD (International Classification of Diseases) 9/10 coding for outpatient pneumonia who were >18 years and without history of tendon injury were included. Patients with history of tendon injury, who received multiple antibiotic therapies for recurrent pneumonia, or who received both FQ and non-FQ regimens during the study period were excluded. Propensity score weighting was used to adjust for selection bias due to contributing risk factors, including demographics (age, sex), comorbidities (diabetes mellitus, chronic kidney disease), and concurrent medications (corticosteroids).

RESULTS

At 1 month, the odds of tendon injury were estimated to be significantly higher (41.9%) in patients receiving FQs compared with those receiving a non-FQ-based regimen (odds ratio [OR] = 1.419, 95% confidence interval [CI] = [1.188-1.698]). The odds of tendon injury were also estimated to be higher (OR = 1.067, 95% CI = [0.975-1.173]) in the FQ population within 180 days, but this effect was not statistically significant. The most frequent sites of tendon injuries were rotator cuff, shoulder, and patellar tendon.

CONCLUSIONS AND RELEVANCE

Prescribers should recognize the risk of tendon injury within 1 month of FQ use when considering treatment regimens for CAP and use alternative options with lower risk whenever possible.

Fluoroquinolone-associated suspected tendonitis and tendon rupture: A pharmacovigilance analysis from 2016 to 2021 based on the FAERS database

Objective: The objective of this study was to scientifically and systematically explore the association between fluoroquinolones (ciprofloxacin, levofloxacin, and moxifloxacin) and tendonitis and tendon rupture through the Food and Drug Administration Adverse Event Reporting System (FAERS) database.

Methods: Disproportionality analysis was used to quantify the signals of fluoroquinolone-associated suspected tendonitis and tendon rupture based on the FAERS data from January 2016 to March 2021. Clinical characteristics, the onset time, oral and intravenous administrations, and the serious outcomes of fluoroquinolone-associated tendonitis and tendon rupture were further analyzed.

Results: Out of 35,667 fluoroquinolone-associated adverse events recorded in the FAERS database during the study period, 1,771 tendonitis and 1,018 tendon ruptures induced by fluoroquinolones as the suspected drug were analyzed, with a median age of 49.88–63.87 years. All three fluoroquinolones detected positive signals of tendonitis and tendon rupture in the four methods. Ciprofloxacin had the strongest statistical association with tendonitis with the highest positive signal values (ROR 98.50, PRR 93.25, IC 6.15, and EBGM 76.80), while levofloxacin showed the strongest statistical association with tendon rupture (ROR 76.38, PRR 73.75, IC 5.84, and EBGM 63.89). Compared with ciprofloxacin and levofloxacin, moxifloxacin was relatively weakly associated with tendonitis and tendon rupture. Oral fluoroquinolone-induced tendonitis and tendon rupture had a stronger signal strength than intravenous administration. The majority of fluroquinolone-related suspected tendonitis and tendon rupture tended to occur within a few days or one month. As for the disability rate of tendonitis, ciprofloxacin counted the highest (n = 461, 50.94%), with moxifloxacin the lowest (n = 20, 29.41%).

Conclusion: Fluoroquinolone-induced tendonitis and tendon rupture tended to occur early and might result in serious outcomes. Our study provided valuable references for early identification of the risk of fluoroquinolone-induced tendonitis and tendon rupture.

Challenges and perspectives of tendon-derived cell therapy for tendinopathy: from bench to bedside

Tendon is composed of dense fibrous connective tissues, connecting muscle at the myotendinous junction (MTJ) to bone at the enthesis and allowing mechanical force to transmit from muscle to bone. Tendon diseases occur at different zones of the tendon, including enthesis, MTJ and midsubstance of the tendon, due to a variety of environmental and genetic factors which consequently result in different frequencies and recovery rates. Self-healing properties of tendons are limited, and cell therapeutic approaches in which injured tendon tissues are renewed by cell replenishment are highly sought after. Homologous use of individual’s tendon-derived cells, predominantly differentiated tenocytes and tendon-derived stem cells, is emerging as a treatment for tendinopathy through achieving minimal cell manipulation for clinical use. This is the first review summarizing the progress of tendon-derived cell therapy in clinical use and its challenges due to the structural complexity of tendons, heterogeneous composition of extracellular cell matrix and cells and unsuitable cell sources. Further to that, novel future perspectives to improve therapeutic effect in tendon-derived cell therapy based on current basic knowledge are discussed.