Achilles Tendonitis Caused by Antibiotics

The indiscriminate use of drugs and more specifically, of antibiotics, is generating innumerable public health problems such as poisoning and bacterial resistance. Of worrying concern is a new side effect that has recently been described: Achilles tendinitis and tendon rupture.

What is Achilles tendonitis?

Achilles tendonitis refers to inflammation and acute pain of the Achilles tendon. Achilles rupture, on the other hand, is a condition that occurs in more severe cases, usually after trauma.


The Achilles tendon is a very strong ligament. It connects the leg to the back of the foot (the heel) and allows for the extension of the foot. The Achilles tendon comprises three powerful muscles: the internal gastrocnemius, the external gastrocnemius, and the soleus.
When this tendon becomes inflamed (tendinitis), people feel the pain in varying intensities. Some people may feel discomfort only when they move while others may experience smarting even at rest.

Antibiotic causes of tendinitis

Although rare, there have been reports of Achilles tendinitis being caused by antibiotics, especially fluoroquinolone-type antibiotics, such as:

  • Moxifloxacin
  • Ciprofloxacin
  • Norfloxacin
  • Levofloxacin
  • Among others…

These broad-spectrum antibiotics are often used to treat respiratory infections (such as pneumonia) or central nervous system infections (such as some meningitis).

However, despite being effective, these antibiotics have been shown to have the side effect of weakening the tendon fibers, predisposing them to microtrauma and acute or chronic inflammation. In more severe cases, the weakness of the tendon has been severe enough to cause a rupture of the tendon.

Tendonitis treatment

It is essential to know that this type of antibiotic side effect is rare, and usually occurs in elderly and male patients (although it has also been reported in women).
Knowing this, the treatment of Achilles tendinitis should focus on replacing the antibiotic with one of another type, for example, penicillin-like amoxicillin.
In some cases, the use of cold compresses and immobilization with a splint has been shown to have good effects in reducing pain and inflammation.

Want more information about Achilles tendonitis?

Dr. Lonny Nodelman and the team over at District Foot and Ankle are here to help answer any questions you may have. Request an appointment today.

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Disclaimer:Any information provided in this blog is not intended to replace medical advice given by qualified professionals.