The Relationship between Antibiotics and Achilles Tendonitis/Ruptures.

Quinolones and fluoroquinolones are broad spectrum antibiotics used to treat bronchitis, urinary tract infections, pneumonia and other respiratory infections3.You may have heard of these antibiotics by their more common names such as Cipro, Levaquin and Floxin. But did you know these antibiotics have been linked to developing tendonitis and even tendon ruptures? 

In one study conducted in 2003, in a sample of 1367 patients, between 2% and 6% of Achilles tendon ruptures could be solely attributed to quinolone use in people 60 years and older8. One study found that the extracellular matrix of the Achilles tendon is compromised from the use of these drugs, meaning it cannot withstand high loads as well as it could without influence from the medications7. This effect is even worse if used in conjunction with corticosteroids7, as they also effect the extracellular matrix weakening the tendon two-fold. In a case study, a patient sustained 2 Achilles tendon ruptures just 6 days into his dose of cipro to treat pneumonia1. Other studies suggest that the effects can be felt as early as 2 hours after first dose and as long as 6 months after beginning a dose of Cipro1

When searching for an answer to what type of patient may be on these antibiotics in conjunction with corticosteroids, a pharmacist in Helena Montana said, “Someone who may have a respiratory infection may be on both Cipro and a steroid at the same time. The quinolone for treatment of the bacteria itself and the corticosteroid for controlling the swelling, making it easier to breathe”5

If you have been on these medications make sure to warm up before activity, stretch and being cognizant of training errors. These are the best ways to avoid injury. A good dynamic warm up can increase the temperature of the tissue making it more resistant to the tensile loads1,4. Tight hamstrings have been linked to increase risk of Achilles rupture due to its effects on the ankle, therefore stretching is very important4. Training errors are easy to make when it comes to physical activity. Making sure to work into your activity progressively is the best way to avoid overuse6. If hiking long miles isn’t something you are used to, be careful and know your limits by using pain as a guide. This is likely to help you avoid compromising your tissues. Daily physical activity is the best way to avoid weakening our tendons. 

Effects of these medications occur at the Achilles tendon most commonly, but other tendons have been implicated including the rotator cuff, fibularis brevis and the quadriceps tendons, refer to Table 11. Other risk factors for developing a tendon rupture are age of over 601, males between 40 and 504, playing competitive sports4, increasing activity level spontaneously from sedentary activity4, obesity, renal failure and hemodialysis1. The list goes on and on, but all factors that increase your risk of tendinitis and rupture. 

Tendons like to be “loaded”, meaning they like to be used. In physical therapy we talk a lot about a “stress shielded tendon”, which is a fancy way for saying a tendon that is prone to injury because it hasn’t been used. The CDC recommends 150 minutes a week of moderate level exercise, or 75 minutes of vigorous exercise, all of which will help keep our tendons health and ready for activity2. Refer to the CDC guidelines for more details on what types of activity counts as moderate or vigorous exercise, or better yet refer to your physical therapist! 

As there are many factors that can affect the health of our tendons, both intrinsic including our anatomy and extrinsic such as training errors, shoe wear and warm up time, medications and how they affect our tendons is something that is relatively unknown to the general public4. As PT’s we greatly encourage everyone to talk to their pharmacists and doctors about the medications you are on and not only check common risk factors but also ask them about uncommon side effects of the drug; such as this increase risk of tendon compromise. Many other drugs have strange side effects that may be skipped over because they are rare, but it is always better to be over informed then under educated. 

Implications of this research should be used by patients to inform their physicians of their physical activity levels and other tendon risk factors they may have before taking the medication. Best informing your health care team helps them make the optimal recommendation of medication for you and your specific situation. Consult with your physical therapist for ideas on best ways to perform a dynamic warm up, proper ways of stretching, treatment if develop a tendinitis and any other questions you have regarding this topic!

Jaycie Loney SPT

Jaycie wrote this post during her summer internship with APRS Physical Therapy. Jaycie is a University of Montana Physical Therapy student and her internship instructor was John-Henry Anderson, PT, DPT, SCS, CSCS.


(Table Taken from Reference 1)

Video to show Tear: 


  1. Akali, A.U., Niranjan, N.S., (July 2008). Management of bilateral Achilles tendon rupture associated with ciprofloxacin: A review and case presentation. Journal of Plastic, Reconstructive & Aesthetic Surgery. Vol: 61, Issue: 7, (830-834). Retrieved from: https://www-sciencedirect.
  2. Current Physical Activity Guidelines. (November 29th 2016).  Center for Disease Control and Prevention. Retrieved from: ty/guid elines.htm
  3. Fookes, C., (May 28th, 2018) Quinolones. Know More, Be Sure. Retrieved from:
  4. Hess, Gregory W CSCS., (February 2010) Achilles Tendon Rupture; A Review of Etiology, Population, Anatomy, Risk Factors and Injury Prevention. Foot and Ankle Specialist. Vol 3, Number 1. Retrieved from: 9355191
  5. Kelsey Wohlfrom, personal communication, July 7th 2018. 
  6. Leppilahti J, Orava S. (February 25th, 1998). Total Achilles tendon rupture: a review. Sports Med. 1998; 25: 79-100. Retrieved from:
  7. Maffulli N, Ajis A. (June 2008). Management of chronic ruptures of the Achilles tendon. J Bone Joint Surg Am. 2008;90: 1348-1360. Retrieved from:
  8. Van der Linden, Paul D., Sturkenboom, Miriam C.J.M., Herings, Ron M.C., et al., Increased Risk of Achilles Tendon Rupture With Quinolone Antibacterial Use, Especially in Elderly Patients Taking Oral Corticosteroids. American Medical Association. Retrieved from: