Fluoroquinolone antibiotics are a broad-spectrum antibiotic, commonly used for urinary tract infections (bladder infections), pneumonia and acute sinusitis.

They are not used in children because animal studies have shown that it can damage the cartilage in weight-bearing joints, such as knees 1,3. Fluoroquinolones have many other possible side effects in adults too, including tendon pain, tendon tears, joint problems and pain (arthritis) and muscle pain.
Joint problems, including arthritis, are rare and have been reported in only about 1% of patients. The patients who experience joint problems form these antibiotics report symptoms that include stiffness, swelling and pain.

What are the symptoms and side-effects of these antibiotics?

The symptoms usually start within a few days of starting the medication but usually resolve within days to weeks after stopping the tablets. Sometimes, irreversible lesions in the cartilage can occur due to the antibiotic having a toxic effect on the cartilage.

One of the more common side effects is tendon pain (tendinopathy) and/or tears. The first case of tendon problems associated with fluoroquinolone antibiotic use was reported in 1983 and since then, the number of tendinopathy complaints have increased. The risk for tendinopathies is highest in people over 60 years, especially if they are using cortisone at the same time.

The tendon symptoms usually start within 1 to 2 weeks of treatment, although some people report symptoms within a few days. Sometimes symptoms can occur within hours of starting the medication and it can take up to 6 months for the symptoms to resolve. Levofloxacin appears to be associated with the highest incidence of tendon problems.

Sadly, the exact mechanism by which these antibiotics cause the problems is still unclear. Other risk factors for people developing tendon pain/tears includes:

  • simultaneous use of corticosteroids (cortisone)
  • organ transplant
  • tendon flexibility
  • poor body biomechanics
  • mechanical strain of muscles/tendons (sport)

Commonly used fluoroquinolones include:

  • ciprofloxacin
  • levofloxacin
  • pefloxacin
  • norfloxacin

Ciprofloxacin is an important antibiotic in a sports team’s doctor’s bag and it is often used to treat “traveller’s diarrhoea” in athletes who are competing overseas. In athletes, the Achilles tendon is the tendon that is most commonly affected (95% of reported tendinopathies), but other tendons in the body can also be involved. This can include:

  1. Tendons of the shoulder
  2. Lower leg tendons
  3. Tendons of the hip

Use of fluoroquinolone antibiotics in sport

  1. Always avoid using these antibiotics, unless there is no alternative.
  2. The athlete and coaching staff must be informed that the athlete is using a fluoroquinolone.
  3. Cortisone (tablets or injection) must not be avoided while the athlete is on fluoroquinolones.
  4. Consider using magnesium and/or antioxidant supplements while on the antibiotic.
  5. Training should be adjusted while the athlete is on fluoroquinolones. The intensity and/or duration of training should be reduced.
  6. If symptoms start in the athlete, all training should be stopped.
  7. Once the course of antibiotics is complete, return to sport should be done gradually.
  8. The athlete should be monitored for at least one month after stopping fluoroquinolone antibiotics and athletes must remember that symptoms can remain for up to 6 months.

Interestingly, other drugs that cause muscle and tendon pain include:

  • statins (cholesterol-lowering drugs)
  • retinol agents (acne medication such as Roaccutane)
  • tetracyclines (antibioitic used to treat various infections, including acne).

This article was submitted by Wendy Snyders, Practice Manager at Lamberti Physiotherapy in Tygervalley, Western Cape. You can discuss with her the implications of anti-biotics on athletes by booking a session via our quick online appointment form.


  1. Conforti et al (2007). Musculoskeletal Adverse Drug Reactions: A Review of Literature and Data from ADR Spontaneous Reporting Databases. Current Drug Safety Vol. 2, No. 1.
  2. Kaleagasioglu and Olcay (2012). Fluoroquinolone-induced Tendinopathy: Etiology and Preventative measures. Tohoku J. Exp. Med. 226 (251 – 258)
  3. Lewis and Cook (2014). Fluoroquinolones and Tendinopathy: A Guide for Athletes and Sports Clinicians and a Systematic Review of the Literature. Journal of Athletic Training 49(3): 422 – 427.
  4. Mederic et al (2011). Musculoskeletal complications of fluoroquinolones: Guidelines and precautions for usage in the athletic population. 3: American Acadamy of Physical Medicine and Rehabilitation 3: 132 – 142.
  5. Images courtesy of Unsplash and David Geier.