Use of fluroquinolone and risk of Achilles tendon rupture: a population-based cohort study

Eur J Clin Pharmacol. 2007 May;63(5):499-503. doi: 10.1007/s00228-007-0265-9. Epub 2007 Mar 3.


Objective: Several case-control studies have reported that the use of fluoroquinolone increases the risk of rupture of the Achilles tendon. Our aim was to estimate this risk by means of a population-based cohort approach.

Setting: Data on Achilles tendon ruptures and fluoroquinolone use were retrieved from three population-based databases that include information on residents of Funen County (population: 470,000) in primary and secondary care during the period 1991-1999. A study cohort of all 28,262 first-time users of fluoroquinolone and all incident cases of Achilles tendon ruptures were identified.

Main outcome measures: The incidence rate of Achilles tendon ruptures among users and non-users of fluoroquinolones and the standardised incidence rate ratio associating fluoroquinolon use with Achilles tendon rupture were the main outcome measures.

Results: Between 1991 and 2002 the incidence of Achilles tendon rupture increased from 22.1 to 32.6/100,000 person-years. Between 1991 and 1999 the incidence of fluoroquinolone users was 722/100,000 person-years, with no apparent trend over time. Within 90 days of their first use of fluoroquinolone, five individuals had a rupture of the Achilles tendon; the expected number was 1.6, yielding an age- and sex-standardised incidence ratio of 3.1 [(95% confidence interval (95%CI): 1.0-7.3). The 90-day cumulative incidence of Achilles tendon ruptures among fluoroquinolone users was 17.7/100,000 (95%CI: 5.7-41.3), which is an increase of 12.0/100,000 (95%CI: 0.0-35.6) compared to the background population.

Conclusion: Fluoroquinolone use triples the risk of Achilles tendon rupture, but the incidence among users is low.

MeSH terms

  • Achilles Tendon / injuries
  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Anti-Infective Agents / adverse effects*
  • Child
  • Cohort Studies
  • Databases as Topic
  • Denmark
  • Female
  • Fluoroquinolones / adverse effects*
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Rupture / chemically induced
  • Rupture / epidemiology
  • Sex Factors
  • Tendon Injuries / chemically induced*
  • Tendon Injuries / epidemiology


  • Anti-Infective Agents
  • Fluoroquinolones