Fluoroquinolone‑Associated Leg Tendon Injury: Evidence‑Based Recommendations

Epidemiology

In patients receiving fluoroquinolones, the odds of Achilles tendon rupture are increased 4.1‑fold (95 % CI 1.8–9.6) compared with non‑exposed individuals【1】.
The absolute excess risk of Achilles tendon rupture is about 12 additional cases per 100 000 persons within 90 days of fluoroquinolone therapy【2】.
Musculoskeletal adverse events occur in 9.3 % of pediatric patients treated with ciprofloxacin versus 6.0 % in controls, indicating a notable increase in children【5】.

The median time from the first ciprofloxacin dose to leg‑pain onset is 6 days【2】.
Tendon‑related pain may appear up to 6 months after discontinuation of the drug【3】.

Age > 60 years confers a four‑fold higher risk of Achilles rupture (≈ 1 in 1 638 patients)【1】.
Concurrent systemic corticosteroid use raises the odds of Achilles rupture to 43.2‑fold (≈ 1 in 979 patients)【1】.
Organ‑transplant recipients (kidney, heart, lung) have an elevated incidence of fluoroquinolone‑related tendon injury【2】.
Patients with pre‑existing rheumatologic or renal disease, prior tendon pathology, or a history of tendon injury are at greater risk【1】.
Athletes and physically active individuals account for roughly 50 % of fluoroquinolone‑associated tendon disorders that occur during sports participation【3】.

While the Achilles tendon is involved in ~90 % of cases, patellar tendon involvement occurs in about 10 % of non‑Achilles tendon injuries【3】.
Bilateral tendon involvement is observed in > 50 % of affected patients, warranting examination of both legs regardless of unilateral symptoms【2】【3】.

Discontinue ciprofloxacin immediately when leg pain or tendon symptoms arise; progression to complete rupture can occur within 48 hours of symptom onset【3】.
Do not restart any fluoroquinolone in patients with a prior fluoroquinolone‑associated tendon disorder【3】.
Perform a bilateral lower‑extremity examination to assess all potential tendon sites, even if pain is reported unilaterally【3】.
Avoid combined NSAID + corticosteroid therapy for pain control, as this combination further increases rupture risk【3】.

Magnesium supplementation during ciprofloxacin therapy is recommended when not contraindicated, to mitigate potential collagen synthesis interference【3】.
Antioxidant supplementation (e.g., vitamin E or coenzyme Q10) may provide protective effects against tendon damage【3】.

The majority of patients experience clinical improvement within 2 months after stopping ciprofloxacin, but ≈ 26 % continue to report pain or functional limitation at follow‑up【3】.

Given the higher musculoskeletal adverse‑event rate in children (9.3 % vs 6.0 % in controls), clinicians should maintain a high index of suspicion for fluoroquinolone‑related leg pain in pediatric patients and consider alternative antibiotics when feasible【5】.