Infectious Diseases Case of the Month Case #2

Pictured at left are the consequences of an infected achilles tendon repair seen by a plastic surgeon at Munson Medical Center. A then 57 yo white female with SLE received a two week course of an antibiotic for a respiratory infection. Towards the end of that course she developed severe bilateral distal calf and heel pain that persisted for months thereafter. Three months after receipt of the antibiotics, in the midst of this ongoing pain, she suffered the spontaneous rupture of her right achilles tendon. The patient had never been on corticosteroids.

She underwent two attempted repairs of the achilles rupture and unfortunately developed a Staphylococcus aureus infection after the second procedure. Ultimately, she was seen by plastic surgery for more definitive repair.

Of the following antibiotics which one was she most likely taking when she developed her leg pain leading to the eventual tendon rupture - azithromycin, Tmp/Smx, linezolid, levofloxacin, or telithromycin?

What antibiotic was she most likely taking prior to her tendon rupture?
Answer: Levofloxacin

This patient's Achilles tendon rupture likely occurred as an adverse effect of taking levofloxacin.

Tendonopathy including tendon rupture is a rare, described complication of therapy with fluoroquinolone antibiotics. The most common site of injury is the Achilles tendon; other sites include the rotator cuff, finger, thumb, patella, and quadriceps. In approximately half the patients Achilles tendonitis is bilateral with rupture occurring in 24-75% of the cases. Quinolones most commonly associated with tendon disorders include pefloxacin, ofloxacin, levofloxacin, norfloxacin, and ciprofloxacin.

Typically a patient with quinolone tendinopathy is elderly and may have associated risk factors including corticosteroid therapy, dialysis or renal dysfunction, transplantation, rheumatic disease, gout, or diabetes mellitus. Corticosteroid therapy and renal dysfunction are risk factors also known to be independently associated with risk of spontaneous tendon rupture.

Onset of tendon symptoms after initiation of quinolone therapy varies widely (from 2 hr to 510 days) but tends to be within the first 1-2 weeks of therapy. Tendon rupture tends to occur with the first 2-3 weeks and usually occurs spontaneously or with very minor trauma. Outcomes of Achilles rupture in the typically elderly patient tend to be poor likely because of advanced age and comorbid illness.


Fluoroquinolone antibiotics are potent, broad spectrum agents whose other serious adverse effects can include alterations of glycemic metabolism, QTc prolongation, and serious dermatologic reactions. These potential problems along with emerging resistance argue for prudent use of these otherwise excellent antimicrobials.

Ref: Melhus, Asa, Fluoroquinolones and tendon disorders, Expert Opin. Drug Saf., 4(2), pgs. 299-309, 2005.

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