Effect of macrolide and fluoroquinolone antibacterials on the risk of ventricular arrhythmia and cardiac arrest: an observational study in Italy using case-control, case-crossover and case-time-control designs

Association Between Fluoroquinolones and Major Adverse Cardiovascular Events: A Systematic Review

Fluoroquinolones (FQs) are routinely administered antibiotics that have demonstrated an increased propensity to cause major adverse cardiovascular events (MACE). We conducted a systematic review aimed to investigate the association between FQ usage and the risk of MACE. A comprehensive literature search was conducted using PubMed, Scopus, and the Cochrane Library from inception to September 2023 to retrieve studies comparing FQ administration with placebo and reporting the occurrence of MACE. Relevant studies that explored the occurrence of MACE, defined as "acute myocardial infarction, stroke, cardiovascular mortality, arrhythmia, or heart failure" with FQ usage were eligible for inclusion. Four studies with a total of 42,808 patients were included. Levofloxacin, moxifloxacin, and gatifloxacin were observed to have an increased propensity to cause MACE, particularly arrhythmias, whereas ciprofloxacin was associated with the lowest risk of causing MACE. Despite the methodological diversity in the included studies, this systematic review uncovered a consistent trend of heightened likelihood of MACE with FQ administration across studies, suggesting that elevated serum concentrations of some FQs may correlate with higher risks of MACE development. This systematic review emphasizes the need for cautious administration of FQs, particularly in patients with a preexisting cardiovascular condition. Routine cardiac monitoring using electrocardiograms is warranted for patients on high doses of FQs to preemptively detect the development of MACE, particularly arrhythmias.

Antimicrobial Resistance and Sports: The Scope of the Problem, Implications for Athletes' Health and Avenues for Collaborative Public Health Action

Antimicrobial resistance (AMR) poses a global threat, leading to increased mortality and necessitating urgent action-however, its impact on athletes and the world of sports has hitherto been neglected. Sports environments (including athletic and aquatic) exhibit high levels of microbial contamination, potentially contributing to the spread of resistant microorganisms during physical activities. Moreover, the literature suggests that travel for sports events may lead to changes in athletes' gut microbiomes and potentially impact their antibiotic resistance profiles, raising questions about the broader implications for individual and public/global health. The prevalence of Staphylococcus aureus (S. aureus) among athletes (particularly those engaged in contact or collision sports) ranges between 22.4% and 68.6%, with MRSA strains being isolated in up to 34.9% of tested individuals. Factors such as training frequency, equipment sharing, delayed post-training showers, and a history of certain medical conditions are linked to higher colonization rates. Moreover, MRSA outbreaks have been documented in sports teams previously, highlighting the importance of implementing preventive measures and hygiene protocols in athletic settings. In light of the growing threat of AMR, there is a critical need for evidence-based treatment guidelines tailored to athletes' unique physiological demands to ensure responsible antibiotic use and mitigate potential health risks. While various initiatives-such as incorporating AMR awareness into major sporting events-aim to leverage the broad audience of sports to communicate the importance of addressing AMR, proactive measures (including improved AMR surveillance during large sporting events) will be indispensable for enhancing preparedness and safeguarding both athletes' and the general public's health. This narrative review thoroughly assesses the existing literature on AMR and antibiotic usage in the context of sports, aiming to illuminate areas where information may be lacking and underscoring the significance of promoting global awareness about AMR through sports.

Fluoroquinolones do not provide added risk of out-of-hospital cardiac arrest: a nationwide study

AIM

Conflicting results have been reported regarding the association between fluoroquinolones (FQs) and the risk of out-of-hospital cardiac arrest (OHCA). In particular, it has not become clear whether OHCA in FQ users is related to the inherent comorbidities or whether there is a direct pro-arrhythmic effect of FQs. Therefore, we studied the relation between FQs and OHCA in the general population.

METHODS

Through Danish nationwide registries, we conducted a nested case-control study with OHCA cases of presumed cardiac causes and age/sex/OHCA date-matched non-OHCA controls from the general population. Conditional logistic regression models with adjustments for well-known risk factors of OHCA were employed to estimate the OR with 95% CI of OHCA comparing FQs with amoxicillin.

RESULTS

The study population consisted of 46 578 OHCA cases (mean: 71 years (SD: 14.40), 68.8% men) and 232 890 matched controls. FQ was used by 276 cases and 328 controls and conferred no increase in the odds of OHCA compared with amoxicillin use after controlling for the relevant confounders (OR: 0.91 (95% CI: 0.71 to 1.16)). The OR of OHCA associated with FQ use did not vary significantly by age (OR≤65: 0.96 (95% CI: 0.53 to 1.74), OR>65: 0.88 (95% CI: 0.67 to 1.16), p value interaction=0.7818), sex (ORmen: 0.96 (95% CI: 0.70 to 1.31), ORwomen: 0.80 (95% CI: 0.53 to 1.20), p value interaction=0.9698) and pre-existing cardiovascular disease (ORabsent: 1.02 (95% CI: 0.57 to 1.82), ORpresent: 0.98 (95% CI: 0.75 to 1.28), p value interaction=0.3884), including heart failure (ORabsent: 0.93 (95% CI: 0.72 to 1.22), ORpresent: 1.11 (95% CI: 0.61 to 2.02), p value interaction=0.7083) and ischaemic heart disease (ORabsent: 0.85 (95% CI: 0.64 to 1.12), ORpresent: 1.38 (95% CI: 0.86 to 2.21), p value interaction=0.6230).

CONCLUSION

Our findings do not support an association between FQ exposure and OHCA in the general population. This lack of association was consistent in men and women, in all age categories, and in the presence or absence of cardiovascular disease.

Trends in ventricular fibrillation/flutter mortality in US population, 1999 to 2019

BACKGROUND

The Ventricular fibrillation and flutter (VF/VFL)-related mortality trends in the United States (US) population have not yet been investigated. We aimed to assess the trends of VT/VFL-related mortality from 1999 to 2019 among subjects aged more than 15 years old in the US.

METHODS

Data derived from the Centers for Disease Control and Prevention's (CDC) WONDER were analyzed between 1999 and 2019 for VF/VFL-related mortality in subjects aged more than 15 years of age. Adjusted mortality rates (AAMRs) per 100,000 people by year, sex, race and urban-rural status with relative confidence intervals (CIs) were determined. Both the average annual percent change (AAPC) and the annual percent change (APC) with 95% Cis were calculated.

RESULTS

Between 1999 and 2019, 242,125 VT/VFL-related deaths occurred in the US. The overall AAMR steadily declined [AAPC -4.4% (95% CI: -4.7 to -4.0, p < .0001)]. Women showed a more pronounced AAMRs decline [AAPC: -4.8% (95% CI: -5.3 to -4.3, p < .0001). AAMR steadily declined in white subjects and in those of other races [AAPC: -4.5 (95% CI: -4.7 to -4.2, p < .0001) and AAPC: -4.3 (95% CI: -5.1 to -3.5, p < .001), respectively]. Conversely, African Americans showed a steadily AMMR decline between 1999 and 2007 [APC: -8.3 (95% CI: -9.2 to -7.3, p < .0001)], followed by a period of stability from 2007 to 2019 (p = .73). A similar decline was observed for the AAMR among subjects living in urban and rural areas.

CONCLUSIONS

VT/VFL-related mortality steadily decreased between 1999 and 2019 in US. Despite the encouraging results, further efforts are needed to prevent VF/VFL-related mortality in US subjects.

Drug-induced Sudden Death: A Scoping Review

BACKGROUND

The risk of sudden cardiac death (SCD) can be increased with the use of drugs. However, it has been described heterogeneously in the literature.

OBJECTIVE

This study aims to systematically review epidemiological studies dealing with druginduced sudden death, describe their methodologies, and summarize the results found.

METHODS

A scoping review has been carried out using Medline electronic database. The search was limited up to 2020. Epidemiological studies were included, and case reports or case series were excluded.

RESULTS

Out of 3,114 potential articles, 74 were included. Most studies originated from North America (40.5%) or Europe (39.2%). Case-control (47.3%) or cohort (40.5%) studies were the most common designs. The data for outcomes and exposure were retrieved mainly from administrative databases (37.8%) or medical charts/hospital discharge reports (32.4%), but most studies used several sources of information. A composite variable of sudden death or SCD, mainly with ventricular arrhythmia, was the most frequently used endpoint. Only 18.9% of the studies included autopsy results to confirm the death. Psychotropic drugs were the most frequently studied. An increased risk of different outcomes for typical antipsychotics, tricyclic antidepressants, domperidone, and antiepileptics is suggested.

CONCLUSION

The methodologies used were highly heterogeneous, and the results were, in general, not conclusive. An improvement of the methodologies is needed to achieve a conclusion regarding the risk of SCD associated with drug use.

A Rare Case of Ciprofloxacin-Induced Bradycardia Recognized by a Smartwatch

Fluoroquinolones are known to cause cardiac side effects. The most common are ventricular arrhythmias and QT prolongation. We present a case of symptomatic bradycardia secondary to ciprofloxacin use in a patient who presented to the hospital after a smartwatch alert for bradycardia. We believe that the integration of wearable technology in the practice of medicine could provide valuable data and improve patient care in different settings.

Risk of atrial fibrillation in patients with pneumonia

BACKGROUND

Cardiac arrhythmias have a strong association with pneumonia due to the cardiovascular response to infection. Electrocardiographic (ECG) changes in patients with pneumonia are associated with greater disease severity. Atrial fibrillation (AF) is the most common type of cardiac arrhythmia.

OBJECTIVE

This population-based cohort study investigated the incidence of AF among Taiwanese adults with pneumonia using data from the National Health Insurance Research Database in Taiwan.

METHODS

A total of 34,883 patients with pneumonia and an equal number of individuals without pneumonia were eligible after excluding those with a previous diagnosis of AF and matching 1:1 by age, sex, and comorbidities. The Cox proportional hazards model was used to estimate hazard ratios for AF in both groups.

RESULTS

Patients were more likely to develop AF throughout the 1-year follow-up period after the diagnosis of pneumonia. The incidence of AF was 1.2 (414/334,746) per 1000 person-months. Patients with pneumonia had a 4.08-fold (95% confidence interval 3.37-4.95) increased risk for AF compared to patients without pneumonia.

CONCLUSION

Patients with pneumonia exhibited an increased risk for AF, especially in the early period after diagnosis of pneumonia.

Seizures and status epilepticus may be risk factor for cardiac arrhythmia or cardiac arrest across multiple time frames

OBJECTIVE

To determine if Emergency Department (ED) or inpatient encounters for epilepsy or status epilepticus are associated with increased odds of cardiac arrhythmia or cardiac arrest over successively longer time frames.

METHODS

The State Inpatient and ED Databases (from New York, Florida, and California) are statewide datasets containing data on 97% of hospitalizations and ED encounters from these states. In this retrospective, case-crossover study, we used International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify index cardiac arrhythmia encounters. Exposures were inpatient or ED encounters for epilepsy or status epilepticus. The case-crossover analysis tested whether an epilepsy or status epilepticus encounter within various case periods (1, 3, 7, 30, 60, 90, and 180 days prior to index encounter) was associated with subsequent ED or inpatient encounter for cardiac arrhythmia, as compared to control periods of equal length one year prior.

RESULTS

The odds ratio (OR) for cardiac arrhythmia after an epilepsy encounter was significant at all time intervals (OR range 2.37-3.36), and highest at 1 day after epilepsy encounter (OR 3.63, 95% confidence interval [CI] 1.66-7.93, p = 0.0013). The OR after status epilepticus was significant at 7- to 180-day intervals (OR range 2.25-2.74), and highest at 60 days (OR 2.74, CI 2.09-3.61, p < 0.0001).

SIGNIFICANCE

Epilepsy and status epilepticus events are associated with increased odds of subsequent cardiac arrhythmia or cardiac arrest over multiple chronic timeframes. Increased cardiac surveillance may be warranted to minimize morbidity and mortality in patients with epilepsy.

Association of QT-Prolonging Medications With Risk of Autopsy-Defined Causes of Sudden Death

Importance

QT-prolonging medications (QTPMs) are a reported risk factor for sudden cardiac death (SCD) when defined by consensus criteria that presume an arrhythmic cause. The effect of QTPM on autopsy-defined sudden arrhythmic death (SAD) is unknown.

Objective

To evaluate the association between QTPM and autopsy-defined SAD vs nonarrhythmic cause of sudden death.

Design, Setting, and Participants

This prospective countywide case-control study included World Health Organization-defined (presumed) SCD cases who underwent autopsy as part of the San Francisco Postmortem Systematic Investigation of Sudden Cardiac Death Study (POST SCD) to determine arrhythmic or nonarrhythmic cause, and control deaths due to trauma (hereinafter referred to as trauma controls) in San Francisco County, California, from February 1, 2011, to March 1, 2014. Multivariate regression was used to evaluate the association of QTPM with the risk of presumed SCD, autopsy-defined SAD, and non-SAD compared with trauma controls. Medication exposure, determined by prescription lists and postmortem toxicologic findings, was used to calculate a summative QTPM exposure score (range, 0-20). Data were analyzed from September 1, 2018, to June 15, 2019.

Exposure

QT-prolonging medication exposure, as measured by QTPM score (1 indicated low; 2-4, moderate; and >4, high).

Main Outcomes and Measures

Death due to trauma, presumed SCD, and autopsy-defined non-SAD and SAD with no postmortem findings of extracardiac cause.

Results

A total of 629 patients (mean [SD] age, 61.4 [15.7] years; 439 men [69.8%]) were included, 525 with presumed SCDs and 104 traumatic death controls. Individuals with presumed SCDs had higher exposure and were more likely to be taking any QTPM (291 [55.4%] vs 28 [26.9%]; P < .001) than trauma controls. Use of QTPMs was associated with increased risk of presumed SCD in low (odds ratio [OR], 2.25 [95% CI, 1.03-4.96]; P = .04) and high (OR, 6.70 [95% CI, 1.47-30.67]; P = .01) exposure groups. After autopsy adjudication, use of QTPMs was associated with increased risk of non-SAD (low-risk OR, 2.88 [95% CI, 1.18-6.99; P = .02]; moderate-risk OR, 2.62 [95% CI, 1.20-5.73; P = .02]; and high-risk OR, 14.22 [95% CI, 2.91-69.30; P = .001]) but not SAD in all exposure groups. This association was attenuated by the exclusion of occult overdose non-SADs in the highest exposure group.

Conclusions and Relevance

These findings confirm the association between QTPMs and presumed SCD; however, after autopsy, this risk was specific for nonarrhythmic causes of sudden death. Studies using consensus SCD criteria may overestimate the association of QTPMs with the risk of SAD.

Fluoroquinolones and Cardiovascular Risk: A Systematic Review, Meta-analysis and Network Meta-analysis

INTRODUCTION

Several fluoroquinolone antibiotics have been associated with cardiac adverse effects, leading to the withdrawal of some of these agents from the market. Cardiac side effects such as QT prolongation and torsades de pointes (TdP) have also been observed with fluoroquinolones currently on the market. In order to evaluate the cardiac risk of fluoroquinolones as a class, and the comparative risk for each individual drug, we conducted a systematic review, meta-analysis, and network meta-analysis.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched, up to March 2018, for randomized controlled trials, cohort studies, and case-control studies that investigated the association between fluoroquinolone treatment and the risk of cardiovascular events and cardiovascular mortality. We followed the PRISMA 2009 guidelines for data selection and extraction. Outcomes were pooled using random effects models. Direct and indirect comparisons in network meta-analysis were performed using frequentist methods.

RESULTS

Thirteen studies were included in our analyses. Fluoroquinolone use was associated with a statistically significant 85% increase in the risk for arrhythmia (odds ratio [OR] 1.85; 95% confidence interval [CI] 1.22-2.81) and 71% increase in the risk for cardiovascular mortality (OR 1.71; 95% CI 1.39-2.09). Moxifloxacin ranked most likely to have the highest risk for arrhythmia (P-score 0.99) and for cardiovascular mortality (P-score 0.95) by network meta-analysis.

CONCLUSIONS

Our findings show a significant association between fluoroquinolone use and an increased risk for arrhythmia and cardiovascular mortality. Moxifloxacin ranked with the highest probability for cardiovascular adverse events. Further study is required to determine how to reduce the risk for fluoroquinolone-associated cardiac toxicity.

Cardiovascular safety of macrolide and fluoroquinolone antibiotics: An analysis of the WHO database of adverse drug reactions

INTRODUCTION

The cardiovascular safety profile of macrolides and fluoroquinolones has been widely discussed. The aim of the present study is to provide the contribution of real-world data onto the ongoing discussion about cardiovascular toxicity of both macrolides and fluoroquinolones.

METHODS

Reports of adverse drug reactions (ADRs) were retrieved from VigiBase. Macrolides and fluoroquinolones were compared with amoxicillin by using the reporting odds ratio (ROR) as a measure of disproportionality. Macrolides were then compared with fluoroquinolones.

RESULTS

Overall, 6810 reports of ADRs were retrieved: 62% of them were serious and 35% concerned female. Macrolides were more frequently associated with "atrial fibrillation" (ROR = 1.26, CI 1.02-1.57) and "ventricular fibrillation" ROR = 2.60, CI 1.92-3.54) than fluoroquinolones. Antimicrobials more frequently reported for "cardiac disorder" were azithromycin (375 reports) and clarithromycin (302) for macrolides and levofloxacin (470) and moxifloxacin (391) for fluoroquinolones.

CONCLUSION

Our data highlighted that macrolides and fluoroquinolones may influence cardiac rhythm and suggest caution in the prescribing of these drugs to patients with hidden cardiovascular risk factors. Although these ADRs seem to be not common, they have a notable impact in clinical practice because of the huge number of the exposed subjects.

BET 1: What is the incidence of cardiac arrhythmia in adult patients with acute infection prescribed fluoroquinolones?

A shortcut review was carried out to establish the incidence of arrhythmia after prescription of a fluoroquinolone antibiotic. 332 papers were found using the reported searches, of which 14 presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that the incidence of arrhythmia after prescription of a fluoroquinolone antibiotic is low (<3%), but estimates are imprecise.

Association of oral ciprofloxacin, levofloxacin, ofloxacin and moxifloxacin with the risk of serious ventricular arrhythmia: a nationwide cohort study in Korea

OBJECTIVE

To evaluate whether oral ciprofloxacin, levofloxacin, ofloxacin and moxifloxacin increase the risk of ventricular arrhythmia in Korea's general population.

DESIGN

Population-based cohort study using administrative claims data on a national scale in Korea.

SETTING

All primary, secondary and tertiary care settings from 1 January 2015 to 31 December 2015.

PARTICIPANTS

Patients who were prescribed the relevant study medications at outpatient visits.

PRIMARY OUTCOME MEASURES

Each patient group that was prescribed ciprofloxacin, levofloxacin, ofloxacin or moxifloxacin was compared with the group that was prescribed cefixime to assess the risk of serious ventricular arrhythmia (ventricular tachycardia, fibrillation, flutter and cardiac arrest). Using logistic regression analysis with inverse probability of treatment weighting using the propensity score, OR and 95% CI for serious ventricular arrhythmia were calculated for days 1-7 and 8-14 after the patients commenced antibiotic use.

RESULTS

During the study period, 4 888 890 patients were prescribed the study medications. They included 1 466 133 ciprofloxacin users, 1 141 961 levofloxacin users, 1 830 786 ofloxacin users, 47 080 moxifloxacin users and 402 930 cefixime users. Between 1 and 7 days after index date, there was no evidence of increased serious ventricular arrhythmia related to the prescription of ciprofloxacin (OR 0.72; 95% CI 0.49 to 1.06) and levofloxacin (OR 0.92; 95% CI 0.66 to 1.29). Ofloxacin had a 59% reduced risk of serious ventricular arrhythmia compared with cefixime during 1-7 days after prescription. Whereas the OR of serious ventricular arrhythmia after the prescription of moxifloxacin was 1.87 (95% CI 1.15 to 3.11) compared with cefixime during 1-7 days after prescription.

CONCLUSIONS

During 1-7 days after prescription, ciprofloxacin and levofloxacin were not associated with increased risk and ofloxacin showed reduced risk of serious ventricular arrhythmia. Moxifloxacin increased the risk of serious ventricular arrhythmia.

Macrolides, Digoxin Toxicity and the Risk of Sudden Death: A Population-Based Study

INTRODUCTION

Digoxin is commonly prescribed to elderly patients with heart failure and atrial fibrillation, and macrolide antibiotics markedly increase the risk of digoxin toxicity.

OBJECTIVE

The aim was to determine whether, in older patients receiving digoxin, macrolide antibiotics are associated with sudden death.

METHODS

We used a population-based, nested, case-control design from January 1, 1994 to December 31, 2012 in a cohort of Ontario residents aged 66 years or older prescribed digoxin. The primary outcome was the risk of sudden death within 14 days of exposure to one of three antibiotics (erythromycin, clarithromycin, or azithromycin), relative to cefuroxime.

RESULTS

Among 39,072 Ontarians who died suddenly while receiving digoxin, 586 died within 14 days of receiving a study antibiotic. Relative to cefuroxime, we found no statistically significant increase in the risk of sudden death following treatment with erythromycin [adjusted odds ratio (aOR) 0.98; 95% confidence interval (CI) 0.65-1.48], clarithromycin (aOR 1.25; 95% CI 0.94-1.65), or azithromycin (aOR 1.07; 95% CI 0.75-1.53).

CONCLUSION

This finding reinforces the cardiovascular safety of macrolide antibiotics in a high-risk population.

Systematic Review, Meta-analysis, and Network Meta-analysis of the Cardiovascular Safety of Macrolides

Studies reporting an increased risk for cardiac toxicities with macrolide antibiotics have raised concern regarding their cardiovascular safety. We sought to assess the cardiac safety of macrolide antibiotics as a class and of the individual agents by conducting a systematic review and network meta-analysis. Medline, Embase, and the Cochrane Library were searched up to February 2018 for studies reporting on cardiovascular outcomes with macrolides. We followed the PRISMA 2009 guidelines for data selection and extraction. Outcomes were pooled using random-effects models and odds ratios (OR), and 95% confidence intervals (CI) were calculated for arrhythmia, cardiovascular death, and myocardial infarction (MI). A total of 33 studies and data on 22,601,032 subjects were retrieved and included in the current meta-analyses. Macrolide use was not associated with the risk of arrhythmia or cardiovascular mortality. In the primary analysis, macrolide use was associated with a small but statistically significant 15% increase in risk for MI (OR = 1.15 [95% CI, 1.01 to 1.30]). In indirect network meta-analysis, erythromycin and clarithromycin were ranked considerably more likely to be associated with a higher risk for MI and significantly associated with increased risk of MI compared to azithromycin (OR = 1.58 [95% CI, 1.18 to 2.11] and OR = 1.41 [95% CI, 1.11 to 1.81], respectively). Our findings indicate that macrolide antibiotics as a group are associated with a significant risk for MI but not for arrhythmia and cardiovascular mortality. Among the macrolides, erythromycin and clarithromycin were associated with a greater risk of MI. However, it is possible that the association between macrolide use and risk of MI is the result of residual confounding.

Algorithms used to identify ventricular arrhythmias and sudden cardiac death in retrospective studies: a systematic literature review

Drug-induced QT interval prolongation may increase the risk of sudden cardiac death or ventricular arrhythmias (SCD/VA), and therefore affects the safety profile of medications. Administrative databases can be used to inform pharmacoepidemiologic drug safety studies for such rare events. In order to compare event rates between studies, validated operational definitions of these events are needed. We conducted a systematic literature review in PubMed to identify algorithms for SCD/VA. Twenty-two studies were included in the review. Fifteen (68%) studies evaluated International Classification of Diseases, 9th revision (ICD-9) based medical data, of which six utilized a common, validated operational definition. This algorithm was based on principal hospitalization discharge diagnosis or first-listed emergency department visit diagnosis, with an average positive predictive value (PPV) of 85%. Four studies evaluated ICD-9 based death data, of which three utilized a common algorithm with an average PPV of 88%. Further validation of ICD, 10th revision algorithms are needed. In conclusion, we identified a validated algorithm for SCD/VA in medical data, as well as in death data. As such, to ensure comparability between new research and the existing literature, pharmacoepidemiologic research in this area should utilize common, validated algorithms, such as the ones identified in our review, to operationally define these events.

Fluoroquinolones increase the risk of serious arrhythmias: A systematic review and meta-analysis

BACKGROUND

The association between oral fluoroquinolones (FQs) usage and risk of severe arrhythmia-related events (ventricular arrhythmias and sudden cardiac death) remains controversial. Therefore we aimed to quantify this association and to evaluate the effects of FQs on adverse cardiovascular (CV) outcomes.

METHODS

We retrieved data from the Cochrane Collaboration, PubMed, and China National Knowledge Infrastructure (CNKI) databases until August 2017. The studies that reported relative risk (RR) estimates with 95% confidence intervals (CIs) for the associations of interest were included. Data were extracted from the eligible articles, and we used a random effects model to calculate the effect estimates.

RESULTS

Of the 16 studies that were included, 7 studies included serious arrhythmias, 3 studies included CV death, and 11 studies included all-cause death. The pooled RRs of FQs use were: 2.29 (95% CI: 1.20-4.36, P = .01) for serious arrhythmias; 1.60 (95% CI: 1.17-2.20, P = .004) for CV death; and 1.02 (95% CI: 0.76-1.37, P = .92) for all-cause death. The RRs associated with serious arrhythmias were 6.27 for gatifloxacin, 4.20 for moxifloxacin, 1.73 for ciprofloxacin, and 1.41 for levofloxacin. Current FQs users showed an increased risk of serious arrhythmias in the subgroup analysis. Treatment with FQs is associated with an absolute risk increase of 160 additional sudden deaths or ventricular arrhythmias, and 43 additional CV deaths per 1 million treatment courses.

CONCLUSION

The use of FQs could increase the risk of serious arrhythmias and CV death but not increase or all-cause death. Moreover, moxifloxacin and levofloxacin showed a higher risk of serious arrhythmias.

Drug safety of macrolide and quinolone antibiotics in a tertiary care hospital: administration of interacting co-medication and QT prolongation

PURPOSE

Some macrolide and quinolone antibiotics (MQABs) are associated with QT prolongation and life-threatening torsade de pointes (TdP) arrhythmia. MQAB may also inhibit cytochrome P450 isoenzymes and thereby cause pharmacokinetic drug interactions (DDIs). There is limited data on the frequency and management of such risks in clinical practice. We aimed to quantify co-administration of MQAB with interacting drugs and associated adverse drug reactions.

METHODS

We conducted an observational study within our pharmacoepidemiological database derived from electronic medical records of a tertiary care hospital. Among all users of MQAB associated with TdP, we determined the prevalence of additional QT-prolonging drugs and risk factors and identified contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine. Electrocardiographic (ECG) monitoring and associated adverse events were validated in medical records.

RESULTS

Among 3444 administered courses of clarithromycin, erythromycin, azithromycin, ciprofloxacin, levofloxacin, or moxifloxacin, there were 1332 (38.7 %) with concomitant use of additional QT-prolonging drugs. Among those, we identified seven cases of drug-related QT prolongation, but 49.1 % had no ECG monitoring. Of all MQAB users, 547 (15.9 %) had hypokalemia. Forty-four MQAB users had contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine and three of those related adverse drug reactions.

CONCLUSION

In the studied real-life setting, we found a considerable number of MQAB users with additional risk factors for TdP but no ECG monitoring. However, adverse drug reactions were rarely found, and costs vs. benefits of ECG monitoring have to be weighted. In contrast, avoidable risk factors and selected contraindicated pharmacokinetic interactions are clear targets for implementation as automated alerts in electronic prescribing systems.

Oral fluoroquinolone use and serious arrhythmia: bi-national cohort study

OBJECTIVE

To evaluate if oral fluoroquinolone use is associated with an increased risk of serious arrhythmia.

DESIGN

Bi-national cohort study, linking register data on filled prescriptions, cases of serious arrhythmia, and patient characteristics.

SETTING

Denmark, 1997-2011; Sweden, 2006-13.

PARTICIPANTS

The study cohort was derived from a source population of all Danish and Swedish adults, aged 40 to 79 years. 909,656 courses of fluoroquinolone use (ciprofloxacin 82.6%, norfloxacin 12.1%, ofloxacin 3.2%, moxifloxacin 1.2%, and other fluoroquinolones 0.9%) and 909,656 courses of penicillin V use, matched 1:1 on propensity score, were included.

MAIN OUTCOME MEASURE

The main outcome was risk of serious arrhythmia (fatal and non-fatal), comparing courses of fluoroquinolone use with courses of penicillin V use (an antibiotic with no pro-arrhythmic effect). The risk period of interest was current use, defined as days 0-7 of treatment. Subgroup analyses were conducted according to country, sex, age, underlying cardiovascular disease, concomitant use of drugs known to increase the risk of torsades de pointes, fluoroquinolone type, and levels of arrhythmia risk score.

RESULTS

144 cases of serious arrhythmia occurred during follow-up, 66 among current fluoroquinolone users (incidence rate 3.4 per 1000 person years) and 78 among current penicillin users (4.0 per 1000 person years); comparing oral fluoroquinolone treatment with penicillin V, the rate ratio was 0.85 (95% confidence interval 0.61 to 1.18). Compared with penicillin V, the absolute risk difference was -13 (95% confidence interval -35 to 16) cases of serious arrhythmia per 1,000,000 courses of fluoroquinolones. The risk of serious arrhythmia was not statistically significantly increased in any of the subgroups, including analyses by fluoroquinolone type.

CONCLUSIONS

Contrary to previous reports, oral fluoroquinolone treatment was not associated with an increased risk of serious arrhythmia in the general adult populations of Denmark and Sweden. Given the statistical power of the study, even small increases in relative and absolute risk could be ruled out. Since ciprofloxacin was the most commonly used fluoroquinolone in our study, we cannot exclude that intraclass differences influence the risk of serious arrhythmia associated with other less frequently used fluoroquinolones.

[Drug-induced QT interval prolongation: do we know the risks?]

Sudden cardiac death is an important cause of mortality in developed countries, most of them being consequence of acute ventricular arrhythmias. These arrhythmias, in some cases, owe to QT interval prolongation. A major risk factor for this condition is the use of drugs that prolong the QT interval. In fact, in recent years, one of the most common reasons for drug withdrawal or usage restrictions has been drug induced QT interval prolongation that involves both cardiovascular and non-cardiovascular drugs. Taking into account the severity that the occurrence of such an event may have, it is important for clinicians to know the risks of these drugs in certain patients. In this review we analyze the drugs that prolong the QT interval, the risk factors that can enhance QT prolongation and the drug interactions that can increase these risks.

Antibiotic precautions in athletes

CONTEXT

Antibiotics are the mainstay of treatment for bacterial infections in patients of all ages. Athletes who maximally train are at risk for illness and various infections. Routinely used antibiotics have been linked to tendon injuries, cardiac arrhythmias, diarrhea, photosensitivity, cartilage issues, and decreased performance.

EVIDENCE ACQUISITION

Relevant articles published from 1989 to 2012 obtained through searching MEDLINE and OVID. Also, the Food and Drug Administration website was utilized.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 3.

RESULTS

The team physician should consider alternative medications in place of the "drug of choice" when adverse drug effects are a concern for an athlete's health or performance. If alternative medications cannot be selected, secondary preventative measures, including sunscreen or probiotics, may be needed.

CONCLUSION

Physicians choose medications based on a variety of factors to help ensure infection resolution while limiting potential side effects. Extra precautions are indicated when treating athletes with certain antibiotics.

Initial use of one or two antibiotics for critically ill patients with community-acquired pneumonia: impact on survival and bacterial resistance

INTRODUCTION

Several guidelines recommend initial empirical treatment with two antibiotics instead of one to decrease mortality in community-acquired pneumonia (CAP) requiring intensive-care-unit (ICU) admission. We compared the impact on 60-day mortality of using one or two antibiotics. We also compared the rates of nosocomial pneumonia and multidrug-resistant bacteria.

METHODS

This is an observational cohort study of 956 immunocompetent patients with CAP admitted to ICUs in France and entered into a prospective database between 1997 and 2010.

RESULTS

Initial adequate antibiotic therapy was significantly associated with better survival (subdistribution hazard ratio (sHR), 0.63; 95% confidence interval (95% CI), 0.42 to 0.94; P = 0.02); this effect was strongest in patients with Streptococcus pneumonia CAP (sHR, 0.05; 95% CI, 0.005 to 0.46; p = 0.001) or septic shock (sHR: 0.62; 95% CI 0.38 to 1.00; p = 0.05). Dual therapy was associated with a higher frequency of initial adequate antibiotic therapy. However, no difference in 60-day mortality was found between monotherapy (β-lactam) and either of the two dual-therapy groups (β-lactam plus macrolide or fluoroquinolone). The rates of nosocomial pneumonia and multidrug-resistant bacteria were not significantly different across these three groups.

CONCLUSIONS

Initial adequate antibiotic therapy markedly decreased 60-day mortality. Dual therapy improved the likelihood of initial adequate therapy but did not predict decreased 60-day mortality. Dual therapy did not increase the risk of nosocomial pneumonia or multidrug-resistant bacteria.

Variations in antibiotic prescribing of acute rhinosinusitis in United States ambulatory settings

OBJECTIVE

To identify variations in antibiotic treatment of acute rhinosinusitis (ARS) on a national level.

STUDY DESIGN

Cross-sectional study of a national database.

SETTING

Otolaryngology and primary care ambulatory settings.

SUBJECTS AND METHODS

A nationally representative sample of adult outpatient visits was extracted from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Care Survey data for 2006 to 2009. Antibiotic prescriptions associated with ARS were tabulated. Statistical analyses were conducted to identify variations in antibiotic prescribing by patient and physician characteristics.

RESULTS

Antibiotics were prescribed in 82.3% ± 2.6% of 18.7 million visits for ARS (mean age, 46.2 years; 65.9% female). The ratio of primary care physician (PCP) to otolaryngologist (ENT) ARS visits was 18.6:1. Antibiotic prescription rates were inversely related to increasing age groups of 18 to 39, 40 to 64, and ≥ 65 years (87.8%, 81.2%, and 71.0%, respectively; P = .02). Physicians in general medicine outpatient departments, internal medicine, and family medicine were more likely to prescribe antibiotics compared with ENTs (adjusted odds ratio [OR], 7.9 [95% confidence interval (CI), 3.5-17.8]; 6.9 [2.5-19.2]; and 3.9 [2.0-7.7], respectively). The most commonly prescribed antibiotics were azithromycin, amoxicillin, and amoxicillin/clavulanate acid (27.5%, 15.5%, and 14.6%, respectively). The ENTs selected broad-spectrum antibiotics more often than PCPs (94.3% vs 75.7% of visits with antibiotics were broad-spectrum agents; P = .01).

CONCLUSION

Antibiotics were prescribed frequently despite recent consensus guidelines that discourage antibiotic use in mild cases. Furthermore, antibiotic prescription was more likely for younger patients and in primary care settings. This highlights the need to promote awareness of practice guidelines.

The effect of levofloxacin and moxifloxacin on cardiovascular functions of rats with streptozotocin-induced diabetes

Fluoroquinolone antibiotics cause rare, but clinically important, adverse events including hyperglycaemia and hypoglycaemia. The present study focuses on the possible effect of levofloxacin and moxifloxacin on the cardiovascular functions of rats with type I diabetes. Both antibiotics caused bradycardia. Levofloxacin but not moxifloxacin caused hypoglycaemia in diabetic rats and an increase in amplitude of the ST segment revealed by electrocardiogram (ECG) analysis of isolated hearts. In pressurized mesenteric arteries, levofloxacin did not affect the endothelium-derived hyperpolarising factor (EDHF) pathway or its main components, the small-conductance Ca(2+) activated potassium (SK(Ca)) and intermediate-conductance Ca(2+) activated potassium (IK(Ca)) channels. In moxifloxacin-treated rats, an increase in the EDHF response was observed, which was largely attributed to SK(Ca)-activation. In conclusion, levofloxacin and moxifloxacin use appeared to vary but with no evidence of impairment of the cardiovascular function. However, it is still possible that these antibiotics may produce different effects if there are co-morbidities and therefore their use must be with care.

Comparing two types of macrolide antibiotics for the purpose of assessing population-based drug interactions

OBJECTIVE

Clarithromycin strongly inhibits enzyme cytochrome P450 3A4, preventing the metabolism of some other drugs, while azithromycin is a weak inhibitor. Accordingly, blood concentrations of other drugs increase with clarithromycin coprescription leading to adverse events. These macrolide antibiotics also differ on other properties that may impact outcomes. In this study, we compared outcomes in two groups of macrolide antibiotic users in the absence of potentially interacting drugs.

DESIGN

Population-based retrospective cohort study.

SETTING

Ontario, Canada, from 2003 to 2010.

PATIENTS

Patients (mean 74 years) prescribed clarithromycin (n=52 251) or azithromycin (referent group, n=46 618).

MAIN OUTCOMES

The primary outcomes were hospital admission within 30 days of a new antibiotic prescription with any of the 12 conditions examined separately (acute kidney injury, acute myocardial infarction, neuroimaging (proxy for delirium), hypotension, syncope, hyperkalaemia, hyponatraemia, hyperglycaemia, arrhythmia, ischaemic stroke, gastrointestinal bleeding and sepsis). The secondary outcome was mortality.

RESULTS

The baseline characteristics of the two groups, including patient demographics, comorbid conditions, infection type and prescribing physician specialty, were nearly identical. The median daily dose was 1000 mg for clarithromycin and 300 mg for azithromycin and the median duration of dispensing antibiotics was 10 and 5 days, respectively. There was no difference between the groups in the risk of hospitalisation for any condition studied (relative risk ranged from 0.67 to 1.23). Compared with azithromycin, clarithromycin was associated with a slightly higher risk of all-cause mortality (0.46% vs 0.37%, relative risk 1.25, 95% CI 1.03 to 1.52).

CONCLUSIONS

Clarithromycin can be used to assess drug interactions in population-based studies with azithromycin serving as a control group. However, any differences in mortality observed between the two antibiotic groups in the setting of other drug use may be partially attributable to factors beyond the inhibition of drug metabolising enzymes and transporters, as the difference for this outcome was significant.

Azithromycin and the risk of cardiovascular death

BACKGROUND

Although several macrolide antibiotics are proarrhythmic and associated with an increased risk of sudden cardiac death, azithromycin is thought to have minimal cardiotoxicity. However, published reports of arrhythmias suggest that azithromycin may increase the risk of cardiovascular death.

METHODS

We studied a Tennessee Medicaid cohort designed to detect an increased risk of death related to short-term cardiac effects of medication, excluding patients with serious noncardiovascular illness and person-time during and shortly after hospitalization. The cohort included patients who took azithromycin (347,795 prescriptions), propensity-score-matched persons who took no antibiotics (1,391,180 control periods), and patients who took amoxicillin (1,348,672 prescriptions), ciprofloxacin (264,626 prescriptions), or levofloxacin (193,906 prescriptions).

RESULTS

During 5 days of therapy, patients taking azithromycin, as compared with those who took no antibiotics, had an increased risk of cardiovascular death (hazard ratio, 2.88; 95% confidence interval [CI], 1.79 to 4.63; P<0.001) and death from any cause (hazard ratio, 1.85; 95% CI, 1.25 to 2.75; P=0.002). Patients who took amoxicillin had no increase in the risk of death during this period. Relative to amoxicillin, azithromycin was associated with an increased risk of cardiovascular death (hazard ratio, 2.49; 95% CI, 1.38 to 4.50; P=0.002) and death from any cause (hazard ratio, 2.02; 95% CI, 1.24 to 3.30; P=0.005), with an estimated 47 additional cardiovascular deaths per 1 million courses; patients in the highest decile of risk for cardiovascular disease had an estimated 245 additional cardiovascular deaths per 1 million courses. The risk of cardiovascular death was significantly greater with azithromycin than with ciprofloxacin but did not differ significantly from that with levofloxacin.

CONCLUSIONS

During 5 days of azithromycin therapy, there was a small absolute increase in cardiovascular deaths, which was most pronounced among patients with a high baseline risk of cardiovascular disease. (Funded by the National Heart, Lung, and Blood Institute and the Agency for Healthcare Quality and Research Centers for Education and Research on Therapeutics.).

A comparison of pharmacoepidemiological study designs in medication use and traffic safety research

In order to explore how the choice of different study designs could influence the risk estimates, a case–crossover and case–time–control study were carried out and their outcomes were compared with those of a traditional case–control study design that evaluated the association between the exposure to psychotropic medications and the risk of having a motor vehicle accident (MVA). A record-linkage database availing data for 3,786 cases and 18,089 controls during the period 2000–2007 was used. The study designs (i.e., case–crossover and case–time–control) were derived from published literature, and the following psychotropic medicines were examined: antipsychotics, anxiolytics, hypnotics and sedatives, and antidepressants, stratified in the two groups selective serotonin reuptake inhibitors (SSRIs) and other antidepressants. Moreover, in order to further investigate the effects of frequency of psychoactive medication exposure on the outcomes of the case–crossover analysis, the data were also stratified by the number of defined daily doses (DDDs) and days of medication use in the 12 months before the motor vehicle accident. Three-thousand seven-hundred fifty-two cases were included in this second part of the case–crossover analysis. The case–crossover design did not show any statistically significant association between psychotropic medication exposure and MVA risk [e.g., SSRIs—Adj. OR = 1.00 (95 % CI: 0.69–1.46); Anxiolytics—Adj. OR = 0.95 (95 % CI: 0.68–1.31)]. The case–time–control design only showed a borderline statistically significant increased traffic accident risk in SSRI users [Adj. OR = 1.16 (95 % CI: 1.01–1.34)]. With respect to the stratifications by the number of DDDs and days of medication use, the analyses showed no increased traffic accident risk associated with the exposure to the selected medication groups [e.g., SSRIs, <20 DDDs—Adj. OR = 0.65 (95 % CI: 0.11–3.87); SSRIs, 16–150 days—Adj. OR = 0.55 (95 % CI: 0.24–1.24)]. In contrast to the above-mentioned results, our recent case–control study found a statistically significant association between traffic accident risk and exposure to anxiolytics [Adj. OR = 1.54 (95 % CI: 1.11–2.15)], and SSRIs [Adj. OR = 2.03 (95 % CI: 1.31–3.14)]. Case–crossover and case–time–control analyses produced different results than those of our recent case–control study (i.e., case–crossover and case–time–control analyses did not show any statistically significant association whereas the case–control analysis showed an increased traffic accident risk in anxiolytic and SSRI users). These divergent results can probably be explained by the differences in the study designs. Given that the case–crossover design is only appropriate for short-term exposures and the case–time–control design is an elaboration of this latter, it can be concluded that, probably, these two approaches are not the most suitable ones to investigate the relation between MVA risk and psychotropic medications, which, on the contrary, are often use chronically.

Opportunities for minimization of confounding in observational research

Observational epidemiological studies are increasingly used in pharmaceutical research to evaluate the safety and effectiveness of medicines. Such studies can complement findings from randomized clinical trials by involving larger and more generalizable patient populations by accruing greater durations of follow-up and by representing what happens more typically in the clinical setting. However, the interpretation of exposure effects in observational studies is almost always complicated by non-random exposure allocation, which can result in confounding and potentially lead to misleading conclusions. Confounding occurs when an extraneous factor, related to both the exposure and the outcome of interest, partly or entirely explains the relationship observed between the study exposure and the outcome. Although randomization can eliminate confounding by distributing all such extraneous factors equally across the levels of a given exposure, methods for dealing with confounding in observational studies include a careful choice of study design and the possible use of advanced analytical methods. The aim of this paper is to introduce some of the approaches that can be used to help minimize the impact of confounding in observational research to the reader working in the pharmaceutical industry.

Cardiovascular and metabolic safety profiles of the fluoroquinolones

INTRODUCTION

Certain fluoroquinolones share similar indications of use. A comparison among Cardiovascular and metabolic (i.e., dysglycemia) safety profiles of the fluoroquinolones might be particularly useful for the prescribers' decision-making process as well as to hypothesize future researcher purposes.

AREAS COVERED

A literature search was conducted using keywords apt to identify information on safety profile of the fluoroquinolones. Publications concerned with descriptive and etiological surveys were manually reviewed.

EXPERT OPINION

Cardiac alterations and blood glucose impairments might be associated with any fluoroquinolone. However, the benefit/risk profile of these agents could be stratified for the single compounds. Several predisposing factors, such as diabetes, heart illnesses and their related pharmacotherapies, might exacerbate the risk of potentially serious adverse events. In this context, the opportunity of the more appropriate choice among different fluoroquinolones could be applicable.

Safety and tolerability of commonly prescribed oral antibiotics for the treatment of respiratory tract infections

Recent data suggest that adverse events (AEs) associated with the use of antimicrobial drugs are a major safety concern, with antibiotics implicated in a significant proportion (approximately 20%) of all drug-related emergency department visits in the United States. Although most of these visits are attributable to allergic reactions (79%), certain commonly prescribed antibiotics are notable contributors to conditions that range in nature from gastrointestinal to neurologic and/or psychiatric--particularly after ED visits are adjusted per outpatient prescription visits. This article reviews medically significant AEs of agents included in the major antimicrobial classes--AEs that may be underappreciated by general practitioners. Considerable attention is devoted to the fluoroquinolone agents. Also discussed are the assessment procedures of regulatory agencies in Europe and the United States that are in place to evaluate antimicrobial safety more accurately. Offsetting potential risks and benefits associated with currently available antimicrobials in a climate in which new agents are desperately needed to combat continually evolving multiresistant pathogens remains an interesting dilemma in antimicrobial therapy.

Antimicrobials and the risk of torsades de pointes: the contribution from data mining of the US FDA Adverse Event Reporting System

BACKGROUND

Drug-induced torsades de pointes (TdP) is a complex regulatory and clinical problem due to the rarity of this sometimes fatal adverse event. In this context, the US FDA Adverse Event Reporting System (AERS) is an important source of information, which can be applied to the analysis of TdP liability of marketed drugs.

OBJECTIVE

To critically evaluate the risk of antimicrobial-induced TdP by detecting alert signals in the AERS, on the basis of both quantitative and qualitative analyses.

METHODS

Reports of TdP from January 2004 through December 2008 were retrieved from the public version of the AERS. The absolute number of cases and reporting odds ratio as a measure of disproportionality were evaluated for each antimicrobial drug (quantitative approach). A list of drugs with suspected TdP liability (provided by the Arizona Centre of Education and Research on Therapeutics [CERT]) was used as a reference to define signals. In a further analysis, to refine signal detection, we identified TdP cases without co-medications listed by Arizona CERT (qualitative approach).

RESULTS

Over the 5-year period, 374 reports of TdP were retrieved: 28 antibacterials, 8 antifungals, 1 antileprosy and 26 antivirals were involved. Antimicrobials more frequently reported were levofloxacin (55) and moxifloxacin (37) among the antibacterials, fluconazole (47) and voriconazole (17) among the antifungals, and lamivudine (8) and nelfinavir (6) among the antivirals. A significant disproportionality was observed for 17 compounds, including several macrolides, fluoroquinolones, linezolid, triazole antifungals, caspofungin, indinavir and nelfinavir. With the qualitative approach, we identified the following additional drugs or fixed dose combinations, characterized by at least two TdP cases without co-medications listed by Arizona CERT: ceftriaxone, piperacillin/tazobactam, cotrimoxazole, metronidazole, ribavirin, lamivudine and lopinavir/ritonavir.

DISCUSSION

Disproportionality for macrolides, fluoroquinolones and most of the azole antifungals should be viewed as 'expected' according to Arizona CERT list. By contrast, signals were generated by linezolid, caspofungin, posaconazole, indinavir and nelfinavir. Drugs detected only by the qualitative approach should be further investigated by increasing the sensitivity of the method, e.g. by searching also for the TdP surrogate marker, prolongation of the QT interval.

CONCLUSIONS

The freely available version of the FDA AERS database represents an important source to detect signals of TdP. In particular, our analysis generated five signals among antimicrobials for which further investigations and active surveillance are warranted. These signals should be considered in evaluating the benefit-risk profile of these drugs.