OBJECTIVES: To estimate the association between fluoroquinolone use and tendon injury in adolescents. METHODS: We conducted an active-comparator, new-user cohort study using population-based claims data from 2000 to 2018. We included adolescents (aged 12–18 years) with an outpatient prescription fill for an oral fluoroquinolone or comparator broad-spectrum antibiotic. The primary outcome was Achilles, quadricep, patellar, or tibial tendon rupture identified by diagnosis and procedure codes. Tendinitis was a secondary outcome. We used weighting to adjust for measured confounding and a negative control outcome to assess residual confounding. RESULTS: The cohort included 4.4 million adolescents with 7.6 million fills for fluoroquinolone (275 767 fills) or comparator (7 365 684) antibiotics. In the 90 days after the index antibiotic prescription, there were 842 tendon ruptures and 16 750 tendinitis diagnoses (crude rates 0.47 and 9.34 per 1000 person-years, respectively). The weighted 90-day tendon rupture risks were 13.6 per 100 000 fluoroquinolone-treated adolescents and 11.6 per 100 000 comparator-treated adolescents (fluoroquinolone-associated excess risk: 1.9 per 100 000 adolescents; 95% confidence interval −2.6 to 6.4); the corresponding number needed to treat to harm was 52 632. For tendinitis, the weighted 90-day risks were 200.8 per 100 000 fluoroquinolone-treated adolescents and 178.1 per 100 000 comparator-treated adolescents (excess risk: 22.7 per 100 000; 95% confidence interval 4.1 to 41.3); the number needed to treat to harm was 4405. CONCLUSIONS: The excess risk of tendon rupture associated with fluoroquinolone treatment was extremely small, and these events were rare. The excess risk of tendinitis associated with fluoroquinolone treatment was also small. Other more common potential adverse drug effects may be more important to consider for treatment decision-making, particularly in adolescents without other risk factors for tendon injury.
In recent years, there has been a surge in the participation of children in distance running. It is not unusual for an aspiring prepubescent athlete to run 10 to 15 miles daily and to participate in distance races, including marathons (26.2 miles). Although running is a natural activity that can maintain and improve aerobic fitness, racing and particularly training for long distances have their risks. Distance running may induce musculoskeletal, endocrine, hematologic, thermoregulatory, and psychosocial damage. Most reports on such potential damage have not been evaluated with proper epidemiologic scrutiny. It is unknown whether the risk is greater for children than for adults. Nevertheless, the American Academy of Pediatrics wishes to alert the physician to the presence of such risks. Even without established guidelines and extensive documentation, physicians can give children, parents, and coaches advice that fosters healthy physical and psychosocial growth. The most common musculoskeletal problems in the young runner are overuse injuries (ie, those that result from a mechanical stress repeated during a long period). These include epiphyseal plate injuries, stress fractures, patellofemoral syndrome, and chronic tendonitis.1-4 The incidence of such injuries seems to be related to the total distance covered in training and competition.4 Such overuse injuries may lead to a chronic disability (eg, chronic arthritis and growth deformity). Therefore, early medical intervention is important. Female distance runners often experience delayed menarche.5 Its etiology and relevance to health have yet to be established. In most cases, menarche will occur several months after cessation or reduction in volume of training.