Achilles tendon disease in lung transplant recipients: association with ciprofloxacin

Short-Term Exposure to Ciprofloxacin Reduces Proteoglycan Loss in Tendon Explants

Fluoroquinolone antibiotics are associated with increased risk of tendinopathy and tendon rupture, which can occur well after cessation of treatment. We have previously reported that the fluoroquinolone ciprofloxacin (CPX) reduced proteoglycan synthesis in equine tendon explants. This study aimed to determine the effects of CPX on proteoglycan catabolism and whether any observed effects are reversible. Equine superficial digital flexor tendon explant cultures were treated for 4 days with 1, 10, 100 or 300 µg/mL CPX followed by 8 days without CPX. The loss of [³⁵S]-labelled proteoglycans and chemical pool of aggrecan and versican was studied as well as the gene expression levels of matrix-degrading enzymes responsible for proteoglycan catabolism. CPX suppressed [³⁵S]-labelled proteoglycan and total aggrecan loss from the explants, although not in a dose-dependent manner, which coincided with downregulation of mRNA expression of MMP-9, -13, ADAMTS-4, -5. The suppressed loss of proteoglycans was reversed upon removal of the fluoroquinolone with concurrent recovery of MMP and ADAMTS mRNA expression, and downregulated TIMP-2 and upregulated TIMP-1 expression. No changes in MMP-3 expression by CPX was observed at any stage. These findings suggest that CPX suppresses proteoglycan catabolism in tendon, and this is partially attributable to downregulation of matrix-degrading enzymes.

High Incidence of New-Onset Joint Pain in Patients on Fluoroquinolones as Antituberculous Treatment

BACKGROUND

Joint pain is frequently observed in patients on antituberculous treatment, and pyrazinamide is known to be associated with joint pain in patients receiving antituberculous treatment. Fluoroquinolone-associated joint pain and tendon injury have been reported in long-term corticosteroid and transplant recipients, but data are lacking in patients with tuberculosis.

OBJECTIVES

The objective of this study was to examine the incidence of joint pain manifested during administration of antituberculous therapy and their association with fluoroquinolones.

METHODS

Patients diagnosed with tuberculosis attending the outpatient clinic over a period of 1 year were reviewed and divided into 3 groups: group A receiving pyrazinamide, group B receiving a fluoroquinolone, and group C receiving both pyrazinamide and a fluoroquinolone. Latency to onset of joint pain was noted in all 3 groups. Joint pain was initially managed with analgesics, and associated hyperuricemia was treated with allopurinol/febuxostat. Causative drugs were stopped in case of intolerable joint pain.

RESULTS

260 patients (47% females, aged 38 ± 18 years; mean ± SD) were included [group A (n = 140), group B (n = 81), and group C (n = 39)]. Overall, 76/260 (29%) patients developed joint pain: group A - 24/140 patients (17%), group B - 32/81 patients (40%), and group C - 20/39 patients (51%). The median latency to the onset of joint pain was 83 days (interquartile range, IQR 40-167): 55 days (IQR 32-66) in group A, 138 days (IQR 74-278) in group B, and 88 days (IQR 34-183) in group C. Hyperuricemia was present in 12/24 (50%) patients in group A and 11/20 (55%) patients in group C. Pyrazinamide was stopped in 7/140 (5%) patients in group A, fluoroquinolones in 6/81 (7%) patients in group B, and both pyrazinamide and fluoroquinolones were stopped in 5/39 (13%) patients in group C because of intolerable joint pain. Major joints affected were knees and ankles.

CONCLUSION

There is a high incidence of joint pain in patients receiving antituberculous treatment, which is higher when fluoroquinolones or the pyrazinamide-fluoroquinolone combination are administered as compared to pyrazinamide alone.

The Relative Risk of Achilles Tendon Injury in Patients Taking Quinolones

OBJECTIVE

To examine the association between quinolone use and Achilles tendon injury, comparing well-matched cohorts of users of quinolone and nonquinolone antibiotics, and well-matched cohorts of quinolone users and patients not using any nonquinolone antibiotics.

PATIENTS AND METHODS

This retrospective cohort study used Clinformatics data from 2008-2014. Using the propensity score, we matched quinolone users with other antibiotic users and quinolone users with nonusers. The primary outcome was Achilles tendon injury within 6 months. Bivariate analyses determined risk factors for Achilles tendon injury, and conditional logistic regression assessed the impact of quinolone use on these injuries.

RESULTS

A total of 716,522 fluoroquinolone users were matched with other antibiotic users, and 645,034 fluoroquinolone users were matched with nonusers. Rates of Achilles tendon injury were less than 0.5% in all groups. Quinolone use increased the risk of Achilles tendon injury compared with other antibiotic users (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.17-1.31) and nonusers (OR 1.54, 95% CI 1.44-1.64). Interaction with age did not significantly impact the relationship between quinolone use and Achilles injury; however, older quinolone users had a slightly higher relative risk of injury than nonusers versus younger patients. Furthermore, the youngest group of patients had similarly elevated relative risk for injury with quinolone use as did the elderly.

CONCLUSION

Although quinolone use increases the risk of Achilles tendon injury, the absolute risk increase is minimal, especially when compared with similar morbidity patients taking other nonquinolone antibiotics. In relatively healthy populations, such as the one studied here, quinolone use may not make a clinically significant contribution to risk of Achilles tendon injury, at any age range, among those in need of such drugs.

Fluoroquinolones and the Risk of Achilles Tendon Disorders: Update on a Neglected Complication

OBJECTIVE

To evaluate the current evidence and to identify associated risk factors that increase the incidence of this complication. Fluoroquinolone (FQ) has been considered the first-line therapy for uncomplicated urinary infections. FQ has been associated with Achilles tendon disorders, especially during the first month of treatment.

METHODS

Data sources searched included PubMed, MEDLINE, and Scopus from January 1988 to June 2017.

RESULTS

A total of 79 articles were used, with ciprofloxacin representing the most common drug.

CONCLUSION

We found that male gender, advanced age, normal body mass index, chronic renal failure, and concurrent use of corticosteroids increase the risk of Achilles tendon disorders.

Tendon Injury and Fluoroquinolone Use: A Systematic Review

BACKGROUND

Fluoroquinolone antibiotics are commonly used to treat infections and are prescribed by general practitioners, medical specialists and surgeons. Tendon injury has been associated with the use of these medications but the risk associated with newer fluoroquinolones has not been established.

OBJECTIVES

The aim of this systematic review was to evaluate the evidence from observational studies to determine the strength of the association between fluoroquinolone use and tendinopathy, and to identify risk factors for this complication.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Collaboration from inception through May 2013 to identify observational studies focused on tendon injury and fluoroquinolones. Studies with original data were selected for inclusion following the PRISMA guidelines. Of the 560 abstracts screened, 16 relevant studies were independently rated by three authors (WW, AS, DC) using the Newcastle-Ottawa Quality Assessment Scale, and assigned a quality score out of 9. High-quality studies (i.e. scored 4.5 or higher) are summarized in detail in this article. Data were independently extracted by two authors (WW, AS).

RESULTS

Overall, 16 studies were included in our study. Eight were deemed to be of high quality and five specifically evaluated Achilles tendon rupture. In addition, three studies examined Achilles tendinitis, and three included tendon disorders (including any tendon rupture) as an outcome. Results from these studies suggest that individuals exposed to fluoroquinolones are at increased risk for Achilles tendon rupture, particularly within the first month following exposure to the drug (odds ratios ranged from 1.1 to 7.1). One study showed an increased risk of tendon rupture in those over 60 years of age. Five studies stated that individuals taking fluoroquinolones and oral corticosteroids are at increased risk for tendon injury compared with those taking fluoroquinolones alone. Four studies examined the differential effect of a limited number of fluoroquinolones. Ofloxacin had the highest risk of tendon injury in three of the studies.

LIMITATIONS

Included studies are observational in nature and rely on self-report, which may lead to misclassification or underestimation of tendon injury.

CONCLUSIONS

Observational studies showed an increased risk of tendon injury, including tendon rupture and tendinitis, with exposure to fluoroquinolone antibiotic therapy. Although this complication appears to be rare, concomitant corticosteroids increase the risk for tendon injury, which varies depending on the fluoroquinolone used.

Critical review on the socio-economic impact of tendinopathy

There are currently no studies that determine the total burden that tendinopathy places on patients and society. A systematic search was conducted to understand the impact of tendinopathy. It demonstrated that the current prevalence is underestimated, particularly in active populations, such as athletes and workers. Search results demonstrate that due to the high prevalence, impact on patients' daily lives and the economic impact due to work-loss, treatments are significantly higher than currently observed. A well-accepted definition by medical professionals and the public will improve documentation and increase awareness, in order to better tackle the disease burden.

TOL19-001 reduces inflammation and MMP expression in monolayer cultures of tendon cells

Background

Tendinopathies are tendon conditions associated with degeneration and disorganization of the matrix collagen fibers, tendon cells apoptosis and inflammation through up-regulation of proinflammatory cytokines, matrix metalloproteinase (MMP) expression, and prostaglandin E₂ (PGE₂) production. Currently, the pharmacological treatment is mainly based on non-steroidal anti-inflammatory drugs (NSAIDs) use and corticosteroid injections, which both can lead to numerous side effects for patients. TOL19-001 is a diet supplementary composed mostly of spirulina and glucosamine sulfate whose antioxidant properties could be helpful to treat tendinopathies while avoiding taking NSAIDs. In this study we developed an in vitro model of tendinopathy in order to evaluate the therapeutic potential of TOL19-001.

Methods

Tendon cells were cultured on monolayer and treated with interleukin-1β (IL-1β) or ciprofloxacin (CIP), and then, MMPs, PGE2 and collagen expression was evaluated by RT-PCR or Elisa. In addition, a cotreatment with increased doses of TOL19-001 was done. Toxicity of TOL19-001 was evaluated using a metabolic activity assay.

Results

This study demonstrates that IL-1β mimics some aspects of tendinopathies with PGE2 induction, MMP expression (mostly MMP1 and MMP3), and increases of type III/I collagen ratio. CIP, meanwhile, leads to an increase of MMP2 and p65 mRNA, whereas it reduces TIMP1 expression. Scleraxis expression was also increased by CIP whereas it was decreased by IL-1β treatment. Besides, TOL19-001 cotreatment suppresses tendon cell inflammation in vitro, marked by the downregulation of PGE2, MMPs and type III collagen in IL-1β stimulated-cells. TOL19-001 also represses CIP induced-changes.

Conclusions

These findings indicate that TOL19-001 exerts anti-inflammatory effects on tendon cells, which might explain why TOL19-001 diet may improve tendon function in patients with tendon injury. Future research is required to determine TOL19-001 effect on injured or overused tendons in vivo.

Rehabilitation in Patients before and after Lung Transplantation

Lung transplantation is an established treatment for patients with end-stage lung disease. It has been observed that despite near-normal lung function, exercise intolerance and reductions in quality of life (QOL) often persist up to years after transplantation. Several modifiable pre- and posttransplant factors are known to contribute to these persisting impairments. Physiological changes associated with severe and chronic lung disease, limb muscle dysfunction, inactivity/deconditioning, and nutritional depletion can affect exercise capacity and physical functioning in candidates for lung transplantation. After transplantation, extended hospital and intensive care unit stay, prolonged sedentary time, persisting inactivity, immunosuppressant medications and episodes of organ rejection may all impact lung recipients' recovery. Available evidence will be reviewed and content will be proposed (both evidence and experience based) for rehabilitation interventions prior to transplantation, during hospitalization after transplantation, and in both the immediate (≤12 months after hospital discharge) and long-term (>12 months after hospital discharge) posttransplant phase. Outpatient rehabilitation programs including supervised exercise training have been shown to be effective in improving limb muscle dysfunction, exercise capacity, and QOL both before and after transplantation if offered appropriately. Unmet research needs included the absence of sufficiently powered randomized controlled trials measuring the effects of rehabilitation interventions on crucial long-term outcomes such as sustained improvements in QOL, participation in daily activity, survival, incidence of morbidities and cost-effectiveness. Remotely monitored (telehealth) home-based exercise or pedometer-based walking interventions might be interesting alternatives to supervised outpatient rehabilitation interventions in the long-term posttransplant phase and warrant further investigation.

Multiparametric MR Imaging Depicts Glycosaminoglycan Change in the Achilles Tendon during Ciprofloxacin Administration in Healthy Men: Initial Observation

PURPOSE

To determine if quantitative magnetic resonance (MR) imaging techniques (sodium MR imaging, glycosaminoglycan [GAG] chemical exchange saturation transfer [CEST], and T2* mapping) could be used as potential markers for biochemical changes in the Achilles tendon induced by ciprofloxacin intake.

MATERIALS AND METHODS

The ethics committee of the Medical University of Vienna approved the protocol (number 1225/2012), and all patients gave written informed consent. Fourteen ankles from seven men (mean age, 32 years ± 12 [standard deviation]) were included in the study. All patients underwent 7-T MR imaging examinations of the Achilles tendon at baseline and 10 days and 5 months after ciprofloxacin intake. Sodium signal and T2* maps were acquired with the variable echo-time sequence and the GAG CEST values were acquired with a three-dimensional radiofrequency spoiled gradient-recalled-echo sequence.

RESULTS

The mean sodium signal was significantly decreased by 25% in the whole tendon (from baseline to 10 days after ciprofloxacin intake, 130 arbitrary units [au] ± 8 to 98 au ± 5, respectively; P = .023) and returned to baseline after 5 months (116 au ± 10), as observed also at the tendon insertion (baseline, 10 days after ciprofloxacin intake, and 5 months after ciprofloxacin intake, 134 au ± 8, 105 au ± 5, and 119 au ± 9, respectively; P = .034). The mean GAG CEST value in the whole tendon was parallel to the sodium signal with a decrease from baseline to 10 days after ciprofloxacin intake, 4.74% ± 0.75 to 4.50% ± 0.23, respectively (P = .028) and an increase at 5 months after ciprofloxacin intake to 4.88% ± 1.02.

CONCLUSION

In conclusion, this study demonstrates a ciprofloxacin-induced reversible reduction of the normalized sodium MR imaging signal and the GAG CEST effect in the Achilles tendon of healthy volunteers. Changes in sodium MR imaging and GAG CEST in men may reflect a decrease of GAG content in the Achilles tendon after ciprofloxacin intake.

Ciprofloxacin-induced tendinopathy of the gluteal tendons

Fluoroquinolone-induced tendinopathy most commonly affects the Achilles tendon; however, involvement of several other tendons has been described. This is a case report of ciprofloxacin-induced tendinopathy of the gluteal tendons with MRI findings. An obese 25-year-old woman with no significant past medical history was diagnosed with acute pyelonephritis and was treated with intravenous ciprofloxacin. Shortly after her first dose of ciprofloxacin, she developed severe left hip pain and decreased range of motion. MRI of the hips showed bilateral tendinopathy of the gluteal muscle insertion. A diagnosis of ciprofloxacin-induced tendinopathy was made based on her MRI and a Naranjo score of 7. Ciprofloxacin was stopped and her pain quickly resolved. Fluoroquinolones cause tendinopathy in 0.14 % to 0.4 % of patients using these agents. Fluoroquinolone-associated tendinopathy is a serious adverse reaction that can affect many tendons and should be considered in any patient presenting with new musculoskeletal complaints and in whom there is a history of fluoroquinolone use within the preceding 6 months.

Fluoroquinolones and tendinopathy: a guide for athletes and sports clinicians and a systematic review of the literature

CONTEXT

Fluoroquinolone antibiotics have been used for several decades and are effective antimicrobials. Despite their usefulness as antibiotics, a growing body of evidence has accumulated in the peer-reviewed literature that shows fluoroquinolones can cause pathologic lesions in tendon tissue (tendinopathy). These adverse effects can occur within hours of commencing treatment and months after discontinuing the use of these drugs. In some cases, fluoroquinolone usage can lead to complete rupture of the tendon and substantial subsequent disability.

OBJECTIVE

To discuss the cause, pharmacology, symptoms, and epidemiology of fluoroquinolone-associated tendinopathy and to discuss the clinical implications with respect to athletes and their subsequent physiotherapy.

DATA SOURCES

We searched MEDLINE, Cumulative Index to Nursing and Allied Health (CINAHL), Allied and Complementary Medicine Database (AMED), and SPORTDiscus databases for available reports of fluoroquinolone-related tendinopathy (tendinitis, tendon pain, or rupture) published from 1966 to 2012. Search terms were fluoroquinolones or quinolones and tendinopathy, adverse effects, and tendon rupture. Included studies were written in or translated into English. Non-English-language and non-English translations of abstracts from reports were not included (n = 1).

STUDY SELECTION

Eligible studies were any available reports of fluoroquinolone-related tendinopathy (tendinitis, tendon pain, or rupture). Both animal and human histologic studies were included. Any papers not focusing on the tendon-related side effects of fluoroquinolones were excluded (n = 71).

DATA EXTRACTION

Data collected included any cases of fluoroquinolone-related tendinopathy, the particular tendon affected, type of fluoroquinolone, dosage, and concomitant risk factors. Any data outlining the adverse histologic effects of fluoroquinolones also were collected.

DATA SYNTHESIS

A total of 175 papers, including 89 case reports and 8 literature reviews, were identified.

CONCLUSIONS

Fluoroquinolone tendinopathy may not respond well to the current popular eccentric training regimes and may require an alternative, staged treatment approach. Clinicians, athletes, athletic trainers, and their medical support teams should be aware of the need to discuss and possibly discontinue these antibiotics if adverse effects arise.

Marked pathological changes proximal and distal to the site of rupture in acute Achilles tendon ruptures

A laboratory study was performed to evaluate the histopathological features of the macroscopically intact portion of the Achilles tendon in patients undergoing surgery for an acute rupture of the Achilles tendon. Tendon samples were harvested from 29 individuals (21 men, 8 women; mean age: 46 ± 12) who underwent repair of an Achilles tendon tear tear, and from 11 male patients who died of cardiovascular events (mean age: 61). Three pieces of tendon were harvested: at the rupture site, 4 cm proximal to the site of rupture, 1 cm proximal to the insertion of the Achilles tendon on the calcaneum. Slides were assessed using a semiquantitative grading scale assessing fiber structure and arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability, and hyalinization. Intra-observer reliability of the subscore readings was calculated. The pathological features were significantly more pronounced in the samples taken from the site of rupture than in the samples taken proximally and distal to it (0.008 < P < 0.01). There were no significant differences in the mean pathologic sum-scores in the samples taken proximally and distal to the site of rupture. Unruptured Achilles tendons, even at an advanced age, and ruptured Achilles tendons are clearly part of two distinct populations, with the latter demonstrating histopathological evidence of failed healing response even in areas macroscopically normal.

Musculoskeletal complications of fluoroquinolones: guidelines and precautions for usage in the athletic population

Fluoroquinolone antibiotics are associated with a wide spectrum of musculoskeletal complications that involve not only tendon but also cartilage, bone, and muscle. Insights into the pathoetiology of fluoroquinolone toxicity on musculoskeletal tissues have been evolving over recent years. Although the pathoetiology is certainly multifactorial, alterations in cell signaling proteins and direct toxic effects on musculoskeletal tissues have been strongly implicated. Increasing age and concomitant systemic corticosteroid use appear to significantly increase the risk of adverse events. The purpose of this article is to review the musculoskeletal complications associated with use of fluoroquinolone antibiotics by adults; identify risk factors associated with fluoroquinolone toxicity; explore the possible pathoetiology of fluoroquinolone toxicity on tendon, cartilage, bone, and muscle; and offer recommendations regarding evaluation and treatment of fluoroquinolone-associated musculoskeletal complications. In addition, this review will provide recommendations regarding fluoroquinolone use in athletes and return to play after fluoroquinolone exposure.

Pathogenesis of tendinopathies: inflammation or degeneration?

The intrinsic pathogenetic mechanisms of tendinopathies are largely unknown and whether inflammation or degeneration has the prominent role is still a matter of debate. Assuming that there is a continuum from physiology to pathology, overuse may be considered as the initial disease factor; in this context, microruptures of tendon fibers occur and several molecules are expressed, some of which promote the healing process, while others, including inflammatory cytokines, act as disease mediators. Neural in-growth that accompanies the neovessels explains the occurrence of pain and triggers neurogenic-mediated inflammation. It is conceivable that inflammation and degeneration are not mutually exclusive, but work together in the pathogenesis of tendinopathies.

A rare case of ciprofloxacin-induced bilateral rupture of the Achilles tendon

Fluoroquinolone antibiotics have been widely used for over 25 years. Their key adverse effect is tendinopathy. A 76-year-old woman developed bilateral Achilles tendinopathy on the fourth day of fluoroquinolone use. Her doctor advised her to complete the course; however, she went on to sustain bilateral tendoachilles rupture. The patient undertook self-referral to a Primary Care Musculoskeletal Assessment Service, where bilateral Achilles tendon rupture was confirmed by ultrasonography. Surgical repair of both tendons was undertaken. Several months postoperatively the patient was discharged. Fluoroquinolone-related tendinopathy can occur within hours of commencing the medication or up to 6 months post cessation. The incidence of Achilles tendon disorders significantly outweighs pathology in other tendons. Men are up to four times more susceptible than women, hence bilateral rupture in a 76-year-old woman is rare. Patients prescribed fluoroquinolones presenting with tendinopathy require consideration of dose reduction or cessation of fluoroquinolone therapy.

Management of bilateral Achilles tendon rupture associated with ciprofloxacin: A review and case presentation

Fluoroquinolone antibiotics are increasingly being recognized as a cause of Achilles tendinitis and rupture. We report the case of a 62-year old man who developed bilateral Achilles tendon rupture six days following commencement of ciprofloxacin. Tendon exploration and repair was accomplished with the use of a prosthetic substitute (Leeds-Keio ligament) but healing was complicated by left wound breakdown that was successfully repaired with a perforator-based fasciocutaneous flap. A review of the current literature on fluoroquinolone associated achilles ruptures and the various methods of tendon and soft tissue management of the primary or complicated injuries are discussed.

Imaging Findings in Two Cases of Fluoroquinolone-Induced Achilles Tendinopathy

Tendonitis and tendon rupture are rare but recognized complications of fluoroquinolone therapy. Most reports of this problem have appeared in the rheumatology and pharmacology literature, and this topic has received little attention in the radiologic literature. We report two cases of fluoroquinolone-induced tendinopathy and describe their magnetic resonance (MR) and sonographic findings. Although Achilles tendinopathy is generally the result of repetitive injury, it is useful to keep other causes in mind. MR or sonographic findings of Achilles tendinopathy in a patient without history of antecedent trauma should prompt the radiologist to consider fluoroquinolone treatment as a possible causative agent.

Moxifloxacin (Avelox): a novel fluoroquinolone with a broad spectrum of activity

Moxifloxacin (Avelox) is a recently-developed fluoroquinolone that has a broad spectrum of antimicrobial activity, including typical respiratory pathogens, atypical and intracellular respiratory pathogens, Gram-negative pathogens and many anaerobes. This spectrum of activity makes moxifloxacin particularly suitable for the therapy of community-acquired respiratory tract infections. It also has enhanced activity against specific bacteria, such as Mycobacteria spp. and Legionella. Moxifloxacin has pharmacologic characteristics that support once-daily dosing regimens and dual routes of excretion that require little or no adjustment for renal or hepatic insufficiency. The drug has maintained an excellent safety profile based upon broad global usage, and no adverse events have occurred that were unanticipated. Streptococcus pneumoniae, which are resistant to earlier fluoroquinolones, are less likely to be resistant to moxifloxacin.

Rupture of the Achilles and patellar tendons

Certain similarities can clearly be appreciated between Achilles and patellar tendon ruptures. Both are strong tendons that transmit force bridging at least one joint of the lower limb. When healthy, both require massive forces to be disrupted, and both can be weakened through certain systemic disease processes, steroids, and fluoroquinones. Both allow for a variety of innovative management possibilities that ultimately lend themselves to individual surgical preference. We feel that, although surgical management plays an important role in restoring continuity in knee extension and in plantar flexion, functional outcome inevitably relies on patient motivation and a well-established physiotherapy regime. Sports physicians should be able to identify both conditions early in their presentation, but still hold a high index of suspicion for these problems in athletes who have an acute exacerbation of ongoing tendinopathy.

Levofloxacin-associated Achilles tendon rupture

OBJECTIVE

To describe a case of levofloxacin-induced partial Achilles tendon rupture; this occurred in the presence of known risk factors and acute renal failure.

CASE SUMMARY

A 79-year-old white man received levofloxacin for presumed pneumonia, developed acute renal failure in the setting of dehydration, and began having ankle pain on the 12th day of admission. Levofloxacin was discontinued, and magnetic resonance imaging revealed a 6-cm partial tear and degenerative changes.

DISCUSSION

The Naranjo probability scale indicates a possible association between levofloxacin and tendon rupture because the event occurred in the setting of known risk factors such as steroid use, renal failure, older age, and male gender.

CONCLUSIONS

Levofloxacin, like other fluoroquinolones, may cause Achilles tendon rupture, and this may be particularly likely with known risk factors.