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

Ultrasound assessment of acute Achilles tendon rupture and measurement of the tendon gap

Achilles tendon rupture is a common sports-related injury which can carry significant morbidity to patients. Ultrasound remains the workhorse of imaging as it can confirm and localise the extent of Achilles tendon injury. The sonographic anatomy, both normal and ruptured sonographic appearances, as well as sonographic technique must be appreciated to accurately image and report findings, critical to patient management. Particular attention should be applied to the measurement of the diastasis between acutely ruptured tendon ends as this information can assist with informing the decision of conservative vs. operative management. Further work is necessary to standardise the measurement technique including correlating the degree of plantarflexion of the foot with the sonographic tendon gap measures.

Safety of fluoroquinolones

Fluoroquinolones (FQs) are one of the most commonly prescribed classes of antibiotics. Although they were initially well tolerated in randomized clinical trials, subsequent epidemiological studies have reported an increased risk of threatening, severe, long-lasting, disabling and irreversible adverse effects (AEs), related to neurotoxicity and collagen degradation, such as tendonitis, Achilles tendon rupture, aortic aneurysm, and retinal detachment. This article reviews the main potentially threatening AEs, the alarms issued by regulatory agencies and therapeutic alternatives.

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.

Fluoroquinolone-associated suspected tendonitis and tendon rupture: A pharmacovigilance analysis from 2016 to 2021 based on the FAERS database

Objective: The objective of this study was to scientifically and systematically explore the association between fluoroquinolones (ciprofloxacin, levofloxacin, and moxifloxacin) and tendonitis and tendon rupture through the Food and Drug Administration Adverse Event Reporting System (FAERS) database.

Methods: Disproportionality analysis was used to quantify the signals of fluoroquinolone-associated suspected tendonitis and tendon rupture based on the FAERS data from January 2016 to March 2021. Clinical characteristics, the onset time, oral and intravenous administrations, and the serious outcomes of fluoroquinolone-associated tendonitis and tendon rupture were further analyzed.

Results: Out of 35,667 fluoroquinolone-associated adverse events recorded in the FAERS database during the study period, 1,771 tendonitis and 1,018 tendon ruptures induced by fluoroquinolones as the suspected drug were analyzed, with a median age of 49.88–63.87 years. All three fluoroquinolones detected positive signals of tendonitis and tendon rupture in the four methods. Ciprofloxacin had the strongest statistical association with tendonitis with the highest positive signal values (ROR 98.50, PRR 93.25, IC 6.15, and EBGM 76.80), while levofloxacin showed the strongest statistical association with tendon rupture (ROR 76.38, PRR 73.75, IC 5.84, and EBGM 63.89). Compared with ciprofloxacin and levofloxacin, moxifloxacin was relatively weakly associated with tendonitis and tendon rupture. Oral fluoroquinolone-induced tendonitis and tendon rupture had a stronger signal strength than intravenous administration. The majority of fluroquinolone-related suspected tendonitis and tendon rupture tended to occur within a few days or one month. As for the disability rate of tendonitis, ciprofloxacin counted the highest (n = 461, 50.94%), with moxifloxacin the lowest (n = 20, 29.41%).

Conclusion: Fluoroquinolone-induced tendonitis and tendon rupture tended to occur early and might result in serious outcomes. Our study provided valuable references for early identification of the risk of fluoroquinolone-induced tendonitis and tendon rupture.

Do fluoroquinolones increase aortic aneurysm or dissection incidence and mortality? A systematic review and meta-analysis

Objective

The aim of this study was to determine the association between fluoroquinolones (FQs) use, the risk of de novo aortic aneurysm or dissection (AAD), and the prognosis of patients with pre-existing AAD.

Materials and methods

We searched PubMed, EMBASE, CENTRAL, Scopus, and Web of Science on 31 March 2022. Observational studies that evaluated the association of FQs with AAD risk in the general population or FQs with the prognosis of patients with preexisting AAD and presented adjusted effect estimates were included. Two reviewers assessed study eligibility, extracted data, and assessed the risk of bias and certainty of evidence using GRADE.

Results

Of the 13 included studies, 11 focused on the association of FQs with de novo AAD incidence, and only one study investigated the association of FQs with the patient with AAD prognosis. FQ use was associated with an increased risk of de novo AAD within 30 days (RR: 1.42; 95% CI: 1.11-1.81; very low certainty) and 60 days (RR: 1.44; 95% CI: 1.26-1.64; low certainty). Specifically, the association was significant when compared with amoxicillin, azithromycin, doxycycline, or no antibiotic use. Furthermore, patients with preexisting AAD exposure to FQ had an increased risk of all-cause mortality (RR: 1.61; 95% CI: 1.50-1.73; moderate certainty) and aortic-specific mortality (RR: 1.80; 95% CI: 1.50-2.15; moderate certainty), compared to the non-exposed FQ group within a 60-day risk period.

Conclusion

FQs were associated with an increased incidence of AAD in the general population and a higher risk of adverse outcomes in patients with preexisting AAD. Nevertheless, the results may be affected by unmeasured confounding factors. This should be considered by physicians contemplating using FQs in patients with aortic dilation and those at high risk of AAD.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021230171].

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.

Positive Association Between Fluoroquinolone Exposure and Tendon Disorders: A Nationwide Population-Based Cohort Study in Taiwan

Introduction: Fluoroquinolone exposure is reportedly associated with a higher risk of tendon disorders, tendonitis, or tendon rupture. However, studies in East Asian populations have not confirmed these risks in patients with comorbidities or concomitant medication use. This cohort study was designed to investigate the associations among fluoroquinolone exposure, comorbidities, medication use, and tendon disorders in Taiwan.

Materials and Methods: This population-based, nationwide, observational, cohort study used data from the National Health Insurance Research database in Taiwan, a nationwide claims database that covers more than 99% of the Taiwanese population. The study period was from January 2000 to December 2015, and the median follow-up time was 11.05 ± 10.91 years. Patients who were exposed to fluoroquinolones for more than three consecutive days were enrolled, and patients without fluoroquinolone exposure who were matched by age, sex, and index year were enrolled as controls. The associations of comorbidities and concomitant medication use with tendon disorder occurrence were analyzed using Cox regression models.

Results: The incidence of tendon disorders were 6.61 and 3.34 per 10⁵ person-years in patients with and without fluoroquinolone exposure, respectively (adjusted hazard ratio, 1.423; 95% confidence interval [1.02,1.87]; p = 0.021). Sensitivity analyses yielded similar results. Patients under 18 and over 60 years with fluoroquinolone exposure; those with chronic kidney disease, diabetes, rheumatologic disease, cardiac disease, lipid disorder, or obesity; and those who concomitantly used statins, aromatase inhibitors, or glucocorticoids, had a significantly higher risk of tendon disorders.

Conclusion: The long-term risk of tendon disorders was higher in patients with fluoroquinolone exposure than in those without fluoroquinolone exposure. Clinicians should assess the benefits and risks of fluoroquinolone use in patients at high risk of tendon disorders who require fluoroquinolone administration.

Healthcare costs and mortality associated with serious fluoroquinolone-related adverse reactions

The aim of this study was to estimate healthcare costs and mortality associated with serious fluoroquinolone-related adverse reactions in Finland from 2008 to 2019. Serious adverse reaction types were identified from the Finnish Pharmaceutical Insurance Pool's pharmaceutical injury claims and the Finnish Medicines Agency's Adverse Reaction Register. A decision tree model was built to predict costs and mortality associated with serious adverse drug reactions (ADR). Severe clostridioides difficile infections, severe cutaneous adverse reactions, tendon ruptures, aortic ruptures, and liver injuries were included as serious adverse drug reactions in the model. Direct healthcare costs of a serious ADR were based on the number of reimbursed fluoroquinolone prescriptions from the Social Insurance Institution of Finland's database. Sensitivity analyses were conducted to address parameter uncertainty. A total of 1 831 537 fluoroquinolone prescriptions were filled between 2008 and 2019 in Finland, with prescription numbers declining 40% in recent years. Serious ADRs associated with fluoroquinolones lead to estimated direct healthcare costs of 501 938 402 €, including 11 405 ADRs and 3,884 deaths between 2008 and 2019. The average mortality risk associated with the use of fluoroquinolones was 0.21%. Severe clostridioides difficile infections were the most frequent, fatal, and costly serious ADRs associated with the use of fluoroquinolones. Although fluoroquinolones continue to be generally well-tolerated antimicrobials, serious adverse reactions cause long-term impairment to patients and high healthcare costs. Therefore, the risks and benefits should be weighed carefully in antibiotic prescription policies, as well as with individual patients.

Toxicity induced by ciprofloxacin and enrofloxacin: oxidative stress and metabolism

Ciprofloxacin (CIP) (human use) and enrofloxacin (ENR) (veterinary use) are synthetic anti-infectious medications that belong to the second generation of fluoroquinolones. They have a wide antimicrobial spectrum and strong bactericidal effects at very low concentrations via enzymatic inhibition of DNA gyrase and topoisomerase IV, which are required for DNA replication. They also have high bioavailability, rapid absorption with favorable pharmacokinetics and excellent tissue penetration, including cerebral spinal fluid. These features have made them the most applied antibiotics in both human and veterinary medicine. ENR is marketed exclusively for animal medicine and has been widely used as a therapeutic veterinary antibiotic, resulting in its residue in edible tissues and aquatic environments, as well as the development of resistance and toxicity. Estimation of the risks to humans due to antimicrobial resistance produced by CIP and ENR is important and of great interest. Moreover, in rare cases due to their overdose and/or prolonged administration, the development of CIP and ENR toxicity may occur. The toxicity of these fluoroquinolones antimicrobials is mainly related to reactive oxygen species (ROS) and oxidative stress (OS) generation, besides metabolism-related toxicity. Therefore, CIP is restricted in pregnant and lactating women, pediatrics and elderly similarly ENR do in the veterinary field. This review manuscript aims to identify the toxicity induced by ROS and OS as a common sequel of CIP and ENR. Furthermore, their metabolism and the role of metabolizing enzymes were reported.

British Infection Association Guidelines for the Diagnosis and Management of Enteric Fever in England

Enteric fever (EF) is an infection caused by the bacteria called Salmonella Typhi or Paratyphi. Infection is acquired through swallowing contaminated food or water. Most EF in England occurs in people returning from South Asia and other places where EF is common; catching EF in England is rare. The main symptom is fever, but stomach pain, diarrhoea, muscle aches, rash and other symptoms may occur. EF is diagnosed by culturing the bacteria from blood and/or stool in a microbiology laboratory. EF usually responds well to antibiotic treatment. Depending on how unwell the individual is, antibiotics may be administered by mouth or by injection. Over the past several years, there has been an overall increase in resistance to antibiotics used to treat enteric fever, in all endemic areas. Additionally, since 2016, there has been an ongoing outbreak of drug-resistant EF in Pakistan. This infection is called extensively drug-resistant, or XDR, EF and only responds to a limited number of antibiotics. Occasionally individuals develop complications of EF including confusion, bleeding, a hole in the gut or an infection of the bones or elsewhere. Some people may continue to carry the bacteria in their stool for a longtime following treatment for the initial illness. These people may need treatment with a longer course of antibiotics to eradicate infection. Travellers can reduce their risk of acquiring EF by following safe food and water practices and by receiving the vaccine at least a few weeks before travel. These guidelines aim to help doctors do the correct tests and treat patients for enteric fever in England but may also be useful to doctors and public health professionals in other similar countries.

Prediction of potential drug interactions between repurposed COVID-19 and antitubercular drugs: an integrational approach of drug information software and computational techniques data

Introduction:

Tuberculosis is a major respiratory disease globally with a higher prevalence in Asian and African countries than rest of the world. With a larger population of tuberculosis patients anticipated to be co-infected with COVID-19 infection, an ongoing pandemic, identifying, preventing and managing drug–drug interactions is inevitable for maximizing patient benefits for the current repurposed COVID-19 and antitubercular drugs.

Methods:

We assessed the potential drug–drug interactions between repurposed COVID-19 drugs and antitubercular drugs using the drug interaction checker of IBM Micromedex®. Extensive computational studies were performed at a molecular level to validate and understand the drug–drug interactions found from the Micromedex drug interaction checker database at a molecular level. The integrated knowledge derived from Micromedex and computational data was collated and curated for predicting potential drug–drug interactions between repurposed COVID-19 and antitubercular drugs.

Results:

A total of 91 potential drug–drug interactions along with their severity and level of documentation were identified from Micromedex between repurposed COVID-19 drugs and antitubercular drugs. We identified 47 pharmacodynamic, 42 pharmacokinetic and 2 unknown DDIs. The majority of our molecular modelling results were in line with drug–drug interaction data obtained from the drug information software. QT prolongation was identified as the most common type of pharmacodynamic drug–drug interaction, whereas drug–drug interactions associated with cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp) inhibition and induction were identified as the frequent pharmacokinetic drug–drug interactions. The results suggest antitubercular drugs, particularly rifampin and second-line agents, warrant high alert and monitoring while prescribing with the repurposed COVID-19 drugs.

Conclusion:

Predicting these potential drug–drug interactions, particularly related to CYP3A4, P-gp and the human Ether-à-go-go-Related Gene proteins, could be used in clinical settings for screening and management of drug–drug interactions for delivering safer chemotherapeutic tuberculosis and COVID-19 care. The current study provides an initial propulsion for further well-designed pharmacokinetic-pharmacodynamic-based drug–drug interaction studies.

Plain Language Summary

Health service use and costs associated with fluoroquinolone-related tendon injuries

The aim of this study was to assess costs and health service use associated with tendon injuries after the use of fluoroquinolone antimicrobials in Finland during 2002-2012. This retrospective observational study included data from the Finnish Pharmaceutical Insurance Pool's pharmaceutical injury claims. In total, 145 compensated claimants aged ≥18 years presenting tendon injuries after the use of fluoroquinolones (FQs) were included in the study. Outcomes of interest were the number of outpatient visits to primary, secondary, tertiary, and private healthcare services, hospital days, rehabilitation and their costs. Regression models were used to analyze the impact of patient characteristics on hospital days, as well as the relationship between patient characteristics and tendon ruptures. Direct costs of a tendon injury averaged 14,800€ and indirect costs were estimated to be 9,077€ for employed claimants. Fifty-one percent of the claimants were hospitalized, with an average duration of 21 days. Hospitalization was the costliest form of health service use with an average of 9,915€ per hospital episode. Hospital days and direct costs increased with the severity of the injury. Tendon ruptures, in particular bilateral ruptures, required substantially more hospital days and their direct costs were significantly higher than those of uncomplicated tendinitis. Concurrent use of oral corticosteroids and increasing age were associated with a higher likelihood of tendon ruptures. Although rare, FQ-related tendon injuries can result in considerable costs and health service use. Medical staff should remain vigilant when prescribing FQs, especially in groups at increased risk for tendon injuries.

Drug-drug interactions and inappropriate medicines impact on glycemic control and kidney function in older adults with diabetes-attending specialty care institution

PURPOSE

To describe and assess the impact of polypharmacy, and its potential adverse reactions; serious clinically relevant drug-drug interactions (DDIs) and inappropriate medicines (PIMs) on glycemic target, and kidney function in a sample of older adults with type 2 diabetes (T2D).

METHODS

Cross-sectional study was performed in a real-world database including 444 elderly people with T2D from the Portuguese Diabetes Association, aged ≥ 65 years, and registered in 2018. DDIs were analyzed using Micromedex drug-interaction platform and PIMs identified using STOPP criteria version-2.

RESULTS

Polypharmacy was identified in 43.6% of patients. This group of patients has shown to be more females (50 vs. 39.6%, P=0.0208), higher HbA1c targets (P=0.0275), longer diabetes duration (66.4 vs. 54.4%, P=0.0019), more hypertensive (87 vs. 62.9%, P<0.0001), using more insulin (38.1 vs. 26%, P=0.0062), sulfonylureas (37.1 vs. 15.6%, P<0.0001), GLP-1 receptor-agonists (9.7 vs. 3.6%, P=0.0077), metformin-DPP-4 inhibitors (41.2 vs. 29.2%, P=0.0081), and SGLT2 inhibitors (19 vs. 9.6%, P=0.0040). A total of 8.7% of patients had potentially serious clinically relevant DDIs, mainly due to interacting medicine pairs dexamethasone and fluoroquinolones. Furthermore, 23.4% had PIMs, and cardiovascular medicines accounted for largest therapeutic group associated. Polypharmacy found to be associated with twofold greater odds of having HbA1c ≤8%, whereas PIMs associated with 2.5-fold greater odds of having HbA1c ≤9%, and 5.5-folds greater odds of having severe kidney function.

CONCLUSIONS

These findings suggested that there is a potential association between polypharmacy and PIMs and altered glycemic control, and PIMs with the deterioration of kidney function.

Dexamethasone causes calcium deposition and degeneration in human anterior cruciate ligament cells through endoplasmic reticulum stress

BACKGROUND

Dexamethasone is widely used in the treatment of joint diseases due to its anti-inflammatory properties. However, it can cause serious adverse effects. The anterior cruciate ligament (ACL) is an important stabilizer of the knee joint. However, the effect of dexamethasone treatment on the ACL is unclear.

OBJECTIVE

This study aims to explore the effects of dexamethasone on ACL tissues and cells through in vitro and in vivo experiments.

RESULTS

In vitro, we found that after treatment with dexamethasone, human ACL cell apoptosis was increased, type I collagen (COL1A1) content was decreased, mineralization related genes (ENPP1 and ANKH) and calcified nodules were increased, and endoplasmic reticulum stress (ERS) was enhanced. However, ERS inhibitors could significantly inhibit the increase in calcification and the decrease in COL1A1 induced by dexamethasone. In vivo, Wistar rats received the infra-articular injection with dexamethasone (0.5 mg/kg) for 8 weeks. We found that dexamethasone treatment decreased the COL1A1 content and increased the COL2A1 content in the ACL tissues of rats and that chondroid differentiation and mineralization occurred. Meanwhile, the expression of ERS-related proteins was increased.

CONCLUSION

Dexamethasone increased the calcification of ACL cells and caused ACL degeneration through ERS, suggesting that long-term treatment with dexamethasone may cause adverse effects on ACL tissue and increase the risk of long-term rupture.

Fluoroquinolones and the Risk of Aortic Aneurysm or Aortic Dissection: A Systematic Review and Meta-Analysis

OBJECTIVES

We performed a systematic review and meta-analysis to explore the risk of an aortic aneurysm or aortic dissection following fluoroquinolone administration.

METHODS

PubMed, Cochrane library, ClinicalTrials.gov, Embase and Google Scholar were systematically reviewed for controlled studies including adult patients exposed to fluoroquinolones with a primary outcome of aortic aneurysm or aortic dissection.

RESULTS

The meta-analysis was conducted by pooling the effect estimates of four controlled observational studies (one case-control, one case-crossover and two cohort studies). Fluoroquinolone administration more than doubled the risk to develop aortic aneurysm or aortic dissection within 60 days following fluoroquinolone exposure (adjusted Relative Risk [RR] (95% confidence interval [CI]) = 2.14 (1.93 - 2.36); I2 = 15.8%). The quality of the finding was rated as moderate. The risk increase for aortic aneurysm alone was found to be significant (adjusted RR (95% CI) = 2.23 (2.01 - 2.45); I2 = 0%) while the risk increase for aortic dissection alone was not found to be significant (adjusted RR = 1.88 (0.11 - 3.65); I2 = 74%). In subgroup analysis, the risk increase for aortic aneurysm or aortic dissection appeared to be higher in females compared to males (RR = 1.87 (1.24 - 2.51); I2 = 0% versus RR = 1.58 (1.25 - 1.92); I2 = 0%, respectively) and higher in older patients compared to younger patients (RR = 1.72 (1.37 - 2.07); I2 = 0% versus RR = 1.47 (0.91 - 2.04); I2 = 0%, respectively). Subgroup analysis of two studies which measured the duration-response analysis found that as the duration of fluoroquinolone therapy increased from 3 to 14 days to greater than 14 days, there was an increased risk of aortic aneurysm or dissection.

CONCLUSION

The findings of this meta-analysis confirm the positive association between fluoroquinolones and the development of aortic aneurysm or dissection. The data tend to show that this association may be majorly driven by aortic aneurysm. Additionally, some risk factors appear to prevail including prolonged fluoroquinolone treatment and older age.

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.