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

Two mini transverse-incision repair yields better results than percutaneous repair for acute closed midsubstance Achilles tendon rupture: a retrospective case-control study

BACKGROUND

Acute closed midsubstance Achilles tendon rupture(ACMATR) is common, with various treatment methods developed over time. We retrospectively compared the two mini transverse-incision repair (2MTIR) with percutaneous repair (PR) to determine which method yields better results.

METHODS

All cases meeting criteria from 2018 to 2021 in our hospital were included and followed up for 1 to 5 years. A final questionnaire with multiple indexes was conducted via phone call. Comparative analysis of these indexes between the two groups was performed using IBM SPSS Statistics (V.26). Continuous variables that passed tests for normality and equal variance were compared using the Student's t-test. Ranked data were compared using the Mann-Whitney U test. Categorical variables were tested with the chi-square test or Fisher's exact test. A p-value of less than 0.05 was considered statistically significant.

RESULTS

There was one rerupture in the PR group. The final indexes for "Tightness Feeling", "Heel Rising Strength", and "Foot Numbness" were statistically different (P < 0.05) between the two groups. The "Re-rupture" and "Return to Sports" indexes showed no statistical difference (P > 0.05).

CONCLUSIONS

The 2MTIR technique provided a technically straightforward, minimally invasive procedure with well-preserved paratenon and direct end-to-end firm fixation in cases of ACMATR. It resulted in very low complications, easy rehabilitation, and full weight-bearing as early as 5-6 weeks postoperatively, yielding better functional outcomes compared to the PR technique in the 1-5 year follow-up.

TRIAL REGISTRATION

The study was preliminarily registered and approved by the University of Hong Kong-Shenzhen Hospital Ethical Board with Project number: hkuszh2023074 on May 4, 2023.

Achilles Tendon Rupture

There are many high-level studies comparing nonoperative treatment, open repair, and minimally invasive repair for Achilles tendon ruptures. This article summarizes the most up-to-date literature comparing these treatment options. The authors' preferred protocol for nonoperative treatment is discussed. Preferred techniques for open repair and chronic Achilles repair are discussed with reference to the literature.

Hyperuricemia as an independent risk factor for achilles tendon rupture in male: a case-control study

OBJECTIVE

To study the correlation between achilles tendon rupture (ATR) and hyperuricemia, also verify the known risk factors for ATR.

METHODS

A retrospective review of 488 subjects was performed (182 with Achilles tendon rupture, 306 controls with ankle sprains). Demographic variables and risk factors for rupture were tabulated and compared. The baseline data and related indicators were compared, and the risk factors of ATR were analyzed by constructing a binary logistic regression model.

RESULTS

Univariate logistic analysis showed that BMI, smoking, and hyperuricemia were risk factors for the development of ATR (OR = 1.65, 95%CI 1.13-2.42, P = 0.01; OR = 1.47, 95%CI 1.00-2.24, P < 0.05; OR = 2.85, 95%CI 1.84-4.42, P < 0.01). Multifactorial analysis showed that BMI ≥ 25 kg/m2, smoking, and hyperuricemia were independent risk factors for the development of ATR (OR = 1.66, 95%CI 1.11-2.49, P = 0.01; OR = 2.15, 95%CI 1.28-3.60, P < 0.01; OR = 3.06, 95%CI 1.92-4.89, P < 0.01). Among the blood biochemical indicators, total cholesterol (TC) and uric acid (UA) were independent risk factors for the occurrence of ATR (OR = 1.54, 95% CI 1.12-2.12, P = 0.01; OR = 1.01, 95% CI 1.01-1.01, P < 0.01).

CONCLUSION

Our study confirmed that, as in previous results, higher BMI, smoking, and total cholesterol are risk factors for ATR, Hyperuricemia may contribute to the development of ATR, and adjunctive tests for TC and UA in the blood biochemistry may be helpful in predicting the risk of ATR.

Risk factors for Achilles tendon rupture: an updated systematic review

OBJECTIVE

Identifying risk factors for Achilles Tendon Rupture (ATR) is one of the first necessary steps for its prevention. This systematic review aimed to update the systematic review published in 2014 in ATR etiology.

METHODOLOGY

A systematic review was carried out using PubMed, EBSCO, and ScienceDirect databases. All types of research studies (Randomized Control Trials - RCTs, Cohort studies, Case-control studies and Cross-sectional studies) that considered ATR, were eligible. The inclusion criteria for eligibility of the studies were to be written in the English language, and to include populations of men and/or women, both athletes, and non-athletes, healthy individuals, and patients. Two independent reviewers used the assessment instrument Newcastle-Ottawa Scale independently, to evaluate the quality of each selected study. Further, two reviewers worked independently to extract the study characteristics, and the GRADE methodology was used to assess the level of certainty of each risk factor.

RESULTS

From 9526 studies initially identified, 19 studies were eligible for further analysis to identify risk factors for ATR. Seventeen studies were considered good quality, and two studies fair quality. Low to very low certainty of evidence was found for the following medications: steroids, quinolones, and oral bisphosphonate, as well as for other factors such as chronic tendon inflammation and Achilles' tendinopathy, spring season, diabetes, previous musculoskeletal injury, regular participation in athletic activity, hyperparathyroidism, renal failure, and genetic factors.

CONCLUSIONS

The risk factors found prove that ATR is a multifactorial injury. Appropriate methodologies and well-designed studies are needed to determine the factors and their significance in ATR risk. Finally, the role of biomechanical and psychological aspects in the ATR etiology may be of interest in future studies, as we could not extract relative data in our review.

A Fluorescence-Based, T5 Exonuclease-Amplified DNA Cleavage Assay for Discovering Bacterial DNA Gyrase Poisons

Fluoroquinolones (FQs) are potent antibiotics of clinical significance, known for their unique mechanism of action as gyrase poisons, which stabilize gyrase-DNA cleavage complexes and convert gyrase into a DNA-damaging machinery. Unfortunately, FQ resistance has emerged, and these antibiotics can cause severe side effects. Therefore, discovering novel gyrase poisons with different chemical scaffolds is essential. The challenge lies in efficiently identifying them from compound libraries containing thousands or millions of drug-like compounds, as high-throughput screening (HTS) assays are currently unavailable. Here we report a novel fluorescence-based, T5 exonuclease-amplified DNA cleavage assay for gyrase poison discovery. This assay capitalizes on recent findings showing that multiple gyrase molecules can simultaneously bind to a plasmid DNA molecule, forming multiple gyrase-DNA cleavage complexes on the same plasmid. These gyrase-DNA cleavage complexes, stabilized by a gyrase poison, can be captured using sarkosyl. Proteinase K digestion results in producing small DNA fragments. T5 exonuclease, selectively digesting linear and nicked DNA, can fully digest the fragmented linear DNA molecules and, thus, "amplify" the decrease in fluorescence signal of the DNA cleavage products after SYBR Green staining. This fluorescence-based, T5 exonuclease-amplified DNA cleavage HTS assay is validated using a 50-compound library, making it suitable for screening large compound libraries.

Achilles tendon disorders: An overview of diagnosis and conservative treatment

ABSTRACT

Achilles tendon-related pain affects up to 6% of the US population during their lifetime and is commonly encountered by primary care providers. An accurate diagnosis and early conservative management can improve patient quality of life and reduce unnecessary surgical consultations, saving healthcare dollars. Achilles tendon pathologies can be categorized into acute (pain lasting less than 6 weeks), chronic (pain lasting more than 6 weeks), and acute on chronic (worsening of pain with preexisting chronic Achilles tendon pathology). This article describes the diagnosis, conservative management, indications for imaging, and indications for surgical referral for acute and chronic Achilles tendon rupture, Achilles tendinitis, gastrocnemius strain, plantaris rupture, insertional Achilles tendinopathy, Haglund deformity, and noninsertional Achilles tendinopathy.

Epidemiological Characteristics of Patients Operated for Achilles Tendon Rupture in Shanghai

Objective

To reflect the potential epidemiological characteristics of Achilles tendon (AT) rupture in Shanghai, China, which has been rarely reported before.

Methods

This work is a descriptive epidemiology study. A total of 302 cases of AT rupture admitted to our department between 01/2013 and 02/2020 are analyzed according to telephone follow‐up and medical records. Male to female ratio is 10.3 and the average age is 37.5 years. The record of each case includes age, gender, Body mass index (BMI), quinolone use, corticoid exposure and related medical history/comorbidities. If the case is sports‐related (SR), details including kind of sports, intensity of exercise, exercise time before rupture, specific action that causes rupture and situation of warm‐up are collected. Two independent sample t‐tests and Pearson chi‐square tests are used for statistical analysis.

Results

A total of 252 ruptures are SR. Male to female ratio is 15.6 in SR cases. Most SR ruptures occur in patients aged 25–39 years. Ball games are major sports responsible for rupture: basketball in 95 (37.7%), badminton in 68 (27.0%) and soccer in 62 (24.6%). Acceleration and running start is the specific action that cause most (37.7%) ruptures. AT cases are observed in 91 patients with warm‐up and 161 without preparation before exercise. As a result, more ruptures happened within 10 min' sports in 161 unprepared (22.4%) than in 91 prepared (5.5%) cases. In SR cases, 107 and 145 cases are observed on weekends and weekdays. Of the 302 total cases, 64 are associated with Achilles tendinopathy. Frequently reported factors such as quinolone use and corticoid exposure are found only in two and 11 of all cases, respectively.

Conclusion

Middle‐aged males are common victims of AT rupture in Shanghai. Sports including basketball, badminton, soccer and actions involving in sudden and severe contraction of AT cause most ruptures. Warm‐up before exercise reduces rupture in short time. Factors such as quinolone, corticoid and Achilles tendonitis still need attention.

Current understanding of the diagnosis and management of the tendinopathy: An update from the lab to the clinical practice

Tendinopathy is labeled by many authors as a troublesome, common pathology, present in up to 30% medical care consultations involving musculoskeletal conditions. Despite the lasting interest for addressing tendon pathology, current researchers agree that even the exact definition of the term tendinopathy is unclear. Tendinopathy is currently diagnosed as a clinical hypothesis based on the patient symptoms and physical context. One of the main goals of current clinical management is to personalize treatment approaches to adapt them to the many different needs of the population. Tendons are complex structures that unite muscles and bones with two main objectives: to transmit forces and storage and release energy. Regarding the tensile properties of the tendons, several authors argued that tendons have higher tensile strength compared with muscles, however, are considered less flexible. Tendinopathy is an accepted term which is used to indicated a variety of tissue conditions that appear in injured tendons and describes a non-rupture damage in the tendon or paratendon, which is intensified with mechanical loading Even when the pathoetiology of tendinopathy is unclear, there is a wide array of treatments available to treat and manage tendinopathy. Although tendinitis usually debuts with an inflammatory response, the majority of chronic tendinopathies do not present inflammation and so the choosing of treatment should vary depending on severity, compliance, pain and duration of symptoms. The purpose of this article is to review and provide an overview about the currently research of the tendon diagnosis, management and etiology.

Disproportionality analysis of quinolone safety in children using data from the FDA adverse event reporting system (FAERS)

BACKGROUND

Quinolones are widely prescribed for the treatment or prevention of infectious diseases in children. To gain further insight into quinolone-associated adverse event (AE) in children and better protect pediatric patients, continued surveillance of safety data is essential. The purpose of this study was to characterize the safety profiles of quinolone-associated AEs in children by mining the FDA adverse event reporting system (FAERS).

METHODS

FAERS reports from quarter 1 of 2004 to quarter 1 of 2022 were included in the study. The Medical Dictionary for Regulatory Activities (MedDRA) was used to identify adverse events. Reporting odds ratios (ROR) corresponding 95% confidence intervals (CIs) and information component (IC) along with 95% CIs were calculated to detect drug-AE pairs with higher-than-expected reporting rates within the FAERS from System Organ Classes (SOCs) to Preferred Terms (PTs). Reports were considered as signals if the 95% confidence interval did not contain the null value.

RESULTS

After inclusion criteria were applied, a total of 4,704 reports associated with quinolones were considered. Most FAERS reports associated with ciprofloxacin (N = 2,706) followed by levofloxacin (N = 1,191), moxifloxacin (N = 375), oflaxacin (N = 245) and ozenoxacin (N = 187). The most common age group was 12-18 years. The median weight was 39.0 kilogram. The adverse effects of quinolones emerging for SOCs primarily included Infections and infestations, gastrointestinal symptoms, blood and lymphatic system disorders, cardiac disorders, nervous system disorders, musculoskeletal and connective tissue disorders and psychiatric disorders. The most frequently AE signals at the PT level were pyrexia (N = 236), febrile neutropenia (N = 120), off label use (N = 48), drug resistance (N = 18) and cardiac arrest (N = 22) following the use of ciprofloxacin, levofloxacin, moxifloxacin, ofloxacin, and ozenoxacin, respectively. Serious oznoxacin-associated AE signals were found and have not been documented in the package insert. They included cardiac arrest (N = 22; ROR = 19.83; IC = 3.68), overdose (N = 21; ROR = 4.98; IC = 2.07), seizure (N = 16; ROR = 6.01; IC = 2.29), small for dates baby (N = 9; ROR = 14.7; IC = 3.05), completed suicide (N = 15, ROR = 18.87; IC = 3.51), asthma (N = 9; ROR = 6.69; IC = 2.24;) and hypotension (N = 9; ROR = 3.83; IC = 1.68).

CONCLUSION

This study provided additional evidence with respect to quinolones-related AEs for children. Generally, the findings of this study are compatible with AEs recorded in package inserts. The unexpected signals of ozenoxacin justify active vigilance by clinicians and timely monitoring by pharmacovigilance experts.

The epidemiology and etiology of adhesive capsulitis in the U.S. Medicare population

Background

Adhesive capsulitis (AC) of the shoulder, also known as frozen shoulder, causes substantial pain and disability. In cases of secondary AC, the inflammation and fibrosis of the synovial joint can be triggered by trauma or surgery to the joint followed by extended immobility. However, for primary AC the inciting trigger is unknown. The burden of the disorder among the elderly is also unknown leading to this age group being left out of therapeutic research studies, potentially receiving delayed diagnoses, and unknown financial costs to the Medicare system. The purpose of this analysis was to describe the epidemiology of AC in individuals over the age of 65, an age group little studied for this disorder. The second purpose was to investigate whether specific medications, co-morbidities, infections, and traumas are risk factors or triggers for primary AC in this population.

Methods

We used Medicare claims data from 2010–2012 to investigate the prevalence of AC and assess comorbid risk factors and seasonality. Selected medications, distal trauma, and classes of infections as potential inflammatory triggers for primary AC were investigated using a case–control study design with patients with rotator cuff tears as the comparison group. Medications were identified from National Drug codes and translated to World Health Organization ATC codes for analysis. Health conditions were identified using ICD9-CM codes.

Results

We found a one-year prevalence rate of AC of approximately 0.35% among adults aged 65 years and older which translates to approximately 142,000 older adults in the United States having frozen shoulder syndrome. Diabetes and Parkinson’s disease were significantly associated with the diagnosis of AC in the elderly. Cases were somewhat more common from August through December, although a clear seasonal trend was not observed. Medications, traumas, and infections were similar for cases and controls.

Conclusions

This investigation identified the burden of AC in the US elderly population and applied case–control methodology to identify triggers for its onset in this population. Efforts to reduce chronic health conditions such as diabetes may reduce seemingly unrelated conditions such as AC. The inciting trigger for this idiopathic condition remains elusive.

[Tendinopathies of the Achilles tendon]

Disorders of the Achilles tendon are among the most frequent musculoskeletal injuries in athletes as well as in the general population. It is very important to differentiate the different clinical pictures summarized under the general term achillodynia and to understand the pathogenesis in order to undertake the correct therapeutic measures. In the case of insertional tendinopathies in particular, a rheumatological origin should be clarified. Doppler ultrasound is the most important diagnostic tool. Evidence-based treatment methods include various training programs, shock wave treatment, diverse injection and surgical procedures, each of which are discussed in detail in this article.

A VigiBase descriptive study of fluoroquinolone induced disabling and potentially permanent musculoskeletal and connective tissue disorders

Recent drug safety concerns described fluoroquinolone (FQ)-induced serious musculoskeletal reactions. The objective of this study was to characterize reports with FQ-associated disabling musculoskeletal disorders, from VigiBase. The analysis included all FQ-induced musculoskeletal and connective tissue disorders adverse drug reaction (ADR) reports (up to July-2019), (disabling/incapacitating, or recovered/resolved with sequelae or fatal). We described aspects like reporter, suspected FQs, ADRs, associated corticosteroid therapy. We also looked into the disproportionality data in terms of proportional reporting ratio (PRR) and information component (IC) values. A total of 5355 reports with 13,563 ADRs and 5558 FQs were reported. The majority of reports were for patients aged 18-64 (62.67%), and the female gender prevailed (61.76%). Consumers reported almost half (45.99%), with a peak in reporting rates in 2017. Top reported ADRs were arthralgia (16.34%), tendonitis (11.04%), pain in extremity (9.98%), tendon pain (7.63%), and myalgia (7.17%). Top suspected FQs were levofloxacin (50.04%), ciprofloxacin (38.41%), moxifloxacin (5.16%), ofloxacin (3.17%) and norfloxacin (1.01%). For these, FQs-ADR association was supported by the disproportionality analysis. Corticosteroids were associated with about 7% of tendon related reports. The results augment the existing data on FQs safety concerns, specifically their potential effect on the musculoskeletal system.

Uremic Toxins and Ciprofloxacin Affect Human Tenocytes In Vitro

Tendinopathy is a rare but serious complication of quinolone therapy. Risk factors associated with quinolone-induced tendon disorders include chronic kidney disease accompanied by the accumulation of uremic toxins. Hence, the present study explored the effects of the representative uremic toxins phenylacetic acid (PAA) and quinolinic acid (QA), both alone and in combination with ciprofloxacin (CPX), on human tenocytes in vitro. Tenocytes incubated with uremic toxins +/- CPX were investigated for metabolic activity, vitality, expression of the dominant extracellular tendon matrix (ECM) protein type I collagen, cell-matrix receptor β1-integrin, proinflammatory interleukin (IL)-1β, and the ECM-degrading enzyme matrix metalloproteinase (MMP)-1. CPX, when administered at high concentrations (100 mM), suppressed tenocyte metabolism after 8 h exposure and at therapeutic concentrations after 72 h exposure. PAA reduced tenocyte metabolism only after 72 h exposure to very high doses and when combined with CPX. QA, when administered alone, led to scarcely any cytotoxic effect. Combinations of CPX with PAA or QA did not cause greater cytotoxicity than incubation with CPX alone. Gene expression of the pro-inflammatory cytokine IL-1β was reduced by CPX but up-regulated by PAA and QA. Protein levels of type I collagen decreased in response to high CPX doses, whereas PAA and QA did not affect its synthesis significantly. MMP-1 mRNA levels were increased by CPX. This effect became more pronounced in the form of a synergism following exposure to a combination of CPX and PAA. CPX was more tenotoxic than the uremic toxins PAA and QA, which showed only distinct suppressive effects.

Painful Foot Disorders in the Geriatric Population: A Narrative Review

Painful foot disorders are highly prevalent among older adults causing a significant impact on mobility, function, and risk of falls. Despite its significance, foot pain is often interpreted as a normal part of aging and relatively ignored by health care providers as well as by the older people themselves. Accurate diagnosis of the cause of foot pain is possible for most cases via clinical evaluation without a costly workup. Clinicians should consider, not only musculoskeletal pathologies but also vascular and neurological disorders in older patients with foot pain. Fortunately, most patients improve with physiatric, nonoperative interventions involving biomechanical analysis, function-oriented rehabilitation programs and therapeutic exercise, the use of proper footwear and orthoses, and selected percutaneous interventions, as indicated. In this review, we discuss the physiologic changes of the aging foot relevant to foot pain, the impact of painful foot disorders on function and other key outcomes, and principles of diagnosis and intervention. We also briefly describe painful foot disorders of the older people commonly encountered in a physiatric practice.

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 use of host factors in microbial forensics

Advances have been made in the forensic analysis of microbes and toxins. An underdeveloped and underutilized area in microbial forensics is how the host interacts with microorganisms in a way that provides unique signatures for forensic use. For forensic purposes, an immediate goal is to distinguish a potential victim and innocent person from a perpetrator, and to distinguish between a naturally acquired or intentional infection. Principal methods that are sufficiently developed are characterization of the humoral immune response to microbial antigens including vaccine-induced immunity and detection of antibiotics that may be present in a possible perpetrator. This chapter presents central elements of the host response in a simplified fashion and describes a representative example, which, in the appropriate context, has a high potential of providing evidence that may aid an investigation to distinguish a perpetrator from a victim. This chapter also presents information about the immune system so that the interested reader can have a fuller understanding of the immune response in general.

Real-world safety evaluation of musculoskeletal adverse events associated with Korean pediatric fluoroquinolone use: a nationwide longitudinal retrospective cohort study

Though the pediatric use of fluoroquinolones (FQs) is limited for musculoskeletal safety concerns, the clinical usefulness still exists. This study examined the association between FQs and musculoskeletal adverse events (AEs) as well as the possible risk factors associated with the pediatric FQs uses. This population-based, longitudinal, retrospective study was conducted using Korean National Sample Cohort database originating between 2002 and 2015. An FQ-treated pediatric cohort (<18 years old) was compared to a control treated with amoxicillin. Propensity score matching (PSM) and a Cox proportional hazard model was used to estimate the hazard ratio (HR) for a diagnosis of musculoskeletal AEs within 60 days of the first prescription. Among one million participants, total of 15,706 and 147,840 children were eligible for the FQ and amoxicillin cohorts, respectively. The PSM cohorts showed a slightly increased risk of musculoskeletal AEs after FQ treatment (HR, 1.19; 95% confidence interval, 1.01–1.40; p = 0.042). This association was stronger in males, older patients, and some FQs users. This study indicates that pediatric FQ use is associated with a risk of musculoskeletal AEs and that FQ use should be carefully monitored in groups with certain risk factors. Well-designed pragmatic trials could be expected to clarify these issues.

Biological and chemical changes in fluoroquinolone-associated tendinopathies: a systematic review

INTRODUCTION

The present systematic review investigates the biological and chemical mechanisms that affect the health and structure of tendons following the use of fluoroquinolones (FQs).

SOURCES OF DATA

A total of 12 articles were included, organized, and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

AREAS OF AGREEMENT

Five mechanisms were identified: arrest of proliferation through a decreased activity of cyclin B, CDK-1, CHK-1, and increased PK-1; decrease tenocytes migration through decreased phosphorylation of FAK; decrease type I collagen metabolism through increased MMP-2; chelate effect on ions that influence epigenetics and several enzymes; fluoroquinolones-induced ROS (radical oxygen species) production in mitochondria.

AREAS OF CONTROVERSY

There is no definite structure-damage relationship. The dose-effect relationship is unclear.

GROWING POINTS

Knowing and defining the damage exerted by FQs plays a role in clinical practice, replacing FQs with other antibacterial drugs or using antioxidants to attenuate their pathological effects.

AREAS TIMELY FOR DEVELOPING RESEARCH

Clinical and basic sciences studies for each FQs are necessary.

Clinical implications of the association between fluoroquinolones and tendon rupture: The magnitude of the effect with and without corticosteroids

AIMS

To estimate the relative, absolute and attributable risk of non-traumatic tendon rupture, at various sites, associated with use of fluoroquinolones, with and without concomitant corticosteroids.

METHODS

We conducted cohort and nested case-control studies among fluoroquinolone users in the United Kingdom Clinical Practice Research Datalink Gold. We estimated the excess risk (cohort analysis) and odds ratios (ORs) (case control) of tendon rupture by fluoroquinolone (current, recent and past use versus unexposed) and corticosteroid (current versus unexposed) use.

RESULTS

Among 740 926 patients with a fluoroquinolone prescription, 3957 cases of tendon rupture were identified. The excess risk due to current fluoroquinolone use was low: any tendon rupture 3.73 (95% confidence interval, CI, 2.08-5.39) per 10 000 person-years (PY) and Achilles tendon rupture 2.91 (1.71-4.11) per 10 000 PY. The excess risk of any tendon rupture was much higher for current concomitant fluoroquinolone and corticosteroid use versus corticosteroids alone: 21.2 (11.3-31.2) per 10 000 PY. In the case-control, OR (95% CI) among current fluoroquinolone users versus unexposed patients was elevated: any tendon rupture 1.60 (1.22-2.09), Achilles tendon 2.71 (1.76-4.17) and bicep tendon 1.53 (0.85-2.73). The risk of any tendon rupture was higher among women (OR 2.27 [1.54-3.34]), patients aged 60+ (OR 2.42 [1.74-3.37]), and concomitant corticosteroid use (OR 6.64 [3.99-11.1]).

CONCLUSIONS

Fluoroquinolones increase the risk of Achilles tendon rupture and, to a lesser extent, bicep tendon rupture, but the attributable risk is low. The risk is materially increased with concomitant use of corticosteroids.