Antibiotic-induced cardiac arrhythmias

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.

Potentially inappropriate prescriptions of antibiotics in geriatric psychiatry-a retrospective cohort study

Introduction

Older patients are frequently affected by infectious diseases and adverse drug reactions (ADRs) of consecutively prescribed antibiotics. Particularly within geriatric psychiatry, high rates of potentially inappropriate prescriptions (PIPs) have been described, significantly complicating pharmacological treatment. Therefore, this study aimed to investigate the frequency and characteristics of antibiotic PIPs in geriatric psychiatry.

Methods

Medication charts of 139 patient cases (mean age 78.8 years; 69.8% female) receiving antibiotic treatment on a geriatric psychiatric ward were analyzed. Utilizing previously published definitions of antibiotic PIPs, adequacy of the antibiotic prescriptions was subsequently assessed.

Results

16.3% of all screened patient cases (139/851) received an antibiotic treatment during their inpatient stay. 59.5% of antibiotic prescriptions were due to urinary tract infections, followed by pulmonary (13.3%) and skin and soft tissue infections (11.3%). 46.7% of all antibiotic prescriptions fulfilled at least one PIP criterium, with the prescription of an antibiotic course for more than seven days as the most common PIP (15.3%).

Discussion

Antibiotic PIPs can be considered as a frequent phenomenon in geriatric psychiatry. Especially the use of fluoroquinolones and cephalosporins should be discussed critically due to their extensive side effect profiles. Due to the special characteristics of geriatric psychiatric patients, international guidelines on the use of antibiotics should consider frailty and psychotropic polypharmacy of this patient population more closely.

Association between the Timing of Urinary Antigen Testing and Outcomes in Legionella Pneumonia Patients: A Nationwide Database Study

Objective Recommendations on the timing of Legionella urinary antigen tests for community-acquired pneumonia patients differ among guidelines in Japan, the United States, and European nations. We therefore evaluated the association between the timing of urinary antigen tests and in-hospital mortality in patients with Legionella pneumonia. Methods We conducted a retrospective cohort study using the Diagnosis Procedure Combination database, a nationwide database of acute care inpatients in Japan. Patients who underwent Legionella urinary antigen tests on the day of admission formed the tested group. Patients who were tested on day 2 of admission or later or were unexamined formed the control group. We performed a propensity score matching analysis to compare in-hospital mortality, length of hospital stay and duration of antibiotics use between the two groups. Results Of the 9,254 eligible patients, 6,933 were included in the tested group. One-to-one propensity score matching generated 1,945 pairs. The tested group had a significantly lower 30-day in-hospital mortality than the control group (5.7 vs. 7.7%; odds ratio, 0.72; 95% confidence intervals, 0.55-0.95; p=0.020). The tested group also showed a significantly shorter length of stay and duration of antibiotics use than the control group. Conclusion Urine antigen testing upon admission was associated with better outcomes in patients with Legionella pneumonia. Urine antigen tests upon admission may be recommended for all patients with severe community-acquired pneumonia.

Drug-induced QT prolongation and torsade de pointes: a real-world pharmacovigilance study using the FDA Adverse Event Reporting System database

Introduction: Drug-induced QT prolongation and (or) Torsade de Pointes (TdP) is a well-known serious adverse reaction (ADR) for some drugs, but the widely recognized comprehensive landscape of culprit-drug of QT prolongation and TdP is currently lacking. Aim: To identify the top drugs reported in association with QT prolongation and TdP and provide information for clinical practice. Method: We reviewed the reports related to QT prolongation and TdP in the FDA Adverse Event Reporting System (FAERS) database from January 1, 2004 to December 31, 2022, and summarized a potential causative drug list accordingly. Based on this drug list, the most frequently reported causative drugs and drug classes of QT prolongation and TdP were counted, and the disproportionality analysis for all the drugs was conducted to in detect ADR signal. Furthermore, according to the positive-negative distribution of ADR signal, we integrated the risk characteristic of QT prolongation and TdP in different drugs and drug class. Results: A total of 42,713 reports in FAERS database were considered to be associated with QT prolongation and TdP from 2004 to 2022, in which 1,088 drugs were reported as potential culprit-drugs, and the largest number of drugs belonged to antineoplastics. On the whole, furosemide was the most frequently reported drugs followed by acetylsalicylic acid, quetiapine, citalopram, metoprolol. In terms of drug classes, psycholeptics was the most frequently reported drug classes followed by psychoanaleptics, analgesics, beta blocking agents, drugs for acid related disorders. In disproportionality analysis, 612 drugs showed at least one positive ADR signals, while citalopram, ondansetron, escitalopram, loperamide, and promethazine were the drug with the maximum number of positive ADR signals. However, the positive-negative distribution of ADR signals between different drug classes showed great differences, representing the overall risk difference of different drug classes. Conclusion: Our study provided a real-world overview of QT prolongation and TdP to drugs, and the presentation of the potential culprit-drug list, the proportion of reports, the detection results of ADR signals, and the distribution characteristics of ADR signals may help understand the safety profile of drugs and optimize clinical practice.

Which patient factors increase the risk of fluoroquinolone-associated reactions?

ABSTRACT

Fluoroquinolones commonly are used to treat a variety of infections in the urinary, gastrointestinal, and respiratory tracts. Clinicians should evaluate patients to ensure that a fluoroquinolone is a safe and effective therapy to treat the infection. This article discusses patient factors that increase the risk for serious adverse drug reactions that can occur with fluoroquinolone use.

Administration of macrolide antibiotics increases cardiovascular risk

Background

The increased risk of cardiovascular events in patients prescribed macrolides has been subject to debate for decades.

Methods

Medline, EMBASE databases and ClinicalTrials.gov were searched from inception until August 31, 2022 for studies investigating the link between macrolides and cardiovascular risk. A meta-analysis was performed using a random-effects model.

Results

A total of 80 studies involving 39,374,874 patients were included. No association was found between macrolides and all-cause death. However, compared with the non-macrolide group, macrolides were associated with a significantly increased risk of ventricular arrhythmia or sudden cardiac death (VA or SCD) (azithromycin, relative ratio [RR]: 1.53; 95% confidence interval [CI]: 1.19 to 1.97; clarithromycin, RR: 1.52; 95% CI: 1.07 to 2.16). Besides, administration of macrolides was associated with a higher risk of cardiovascular disease (CVD) death (azithromycin, RR: 1.63; 95% CI: 1.17 to 2.27) and a slightly increased risk of myocardial infarction (MI) (azithromycin, RR: 1.08; 95% CI: 1.02 to 1.15). Interestingly, no association was observed between roxithromycin and adverse cardiac outcomes. Increased risk of VA or SCD was observed for recent or current use of macrolides, MI for former use, and CVD death for current use.

Conclusion

Administration of macrolide antibiotics and timing of macrolide use are associated with increased risk for SCD or VTA and cardiovascular death, but not all-cause death.

Antimicrobial Treatment and Prophylaxis of Plague: Recommendations for Naturally Acquired Infections and Bioterrorism Response

This report provides CDC recommendations to U.S. health care providers regarding treatment, pre-exposure prophylaxis, and postexposure prophylaxis of plague. Yersinia pestis, the bacterium that causes plague, leads to naturally occurring disease in the United States and other regions worldwide and is recognized as a potential bioterrorism weapon. A bioweapon attack with Y. pestis could potentially infect thousands, requiring rapid and informed decision making by clinicians and public health agencies. The U.S. government stockpiles a variety of medical countermeasures to mitigate the effects of a bioterrorism attack (e.g., antimicrobials, antitoxins, and vaccines) for which the 21st Century Cures Act mandates the development of evidence-based guidelines on appropriate use. Guidelines for treatment and postexposure prophylaxis of plague were published in 2000 by a nongovernmental work group; since then, new human clinical data, animal study data, and U.S. Food and Drug Administration approvals of additional countermeasures have become available. To develop a comprehensive set of updated guidelines, CDC conducted a series of systematic literature reviews on human treatment of plague and other relevant topics to collect a broad evidence base for the recommendations in this report. Evidence from CDC reviews and additional sources were presented to subject matter experts during a series of forums. CDC considered individual expert input while developing these guidelines, which provide recommended best practices for treatment and prophylaxis of human plague for both naturally occurring disease and following a bioterrorism attack. The guidelines do not include information on diagnostic testing, triage decisions, or logistics involved in dispensing medical countermeasures. Clinicians and public health officials can use these guidelines to prepare their organizations, hospitals, and communities to respond to a plague mass-casualty event and as a guide for treating patients affected by plague.

A randomized, double-blind, placebo- and positive-controlled crossover study of the effects of durlobactam on cardiac repolarization in healthy subjects

Durlobactam (formerly ETX2514) is a diazabicyclooctane β-lactamase inhibitor that inhibits class A, C, and D β-lactamases. Sulbactam combined with durlobactam has in vitro and in vivo activity against Acinetobacter baumannii including carbapenem- and colistin-resistant isolates and is being developed for treating serious infections due to A. baumannii. The effect of a single supratherapeutic dose of durlobactam on the heart rate corrected QT interval (QTc) was evaluated in healthy subjects in a placebo- and active-controlled, single-infusion, three-way crossover study. Subjects were randomized to 1 of 6 sequences that included a single 3-h i.v. infusion of durlobactam 4 g (supratherapeutic dose), a single 3-h i.v. infusion of placebo, and a single 3-h i.v. infusion of placebo plus a single oral dose of moxifloxacin 400 mg given open-label at the end of the i.v. infusion. In each treatment period, Holter electrocardiogram (ECG) measurements were obtained from predose through 24 h post-start of infusion. For the primary ECG end point, placebo-corrected change-from-baseline corrected QT Fridericia's formula (ΔΔQTcF), no significant change was observed with durlobactam. A concentration-QT analysis demonstrated no significant effect of durlobactam on ECG parameters, including QT interval prolongation. Thus, durlobactam has a low risk for prolonging the QT interval and is unlikely to produce any proarrhythmic effects.

Randomized, Double-Blind, Placebo- and Positive-Controlled Crossover Study of the Effects of Tebipenem Pivoxil Hydrobromide on QT/QTc Intervals in Healthy Subjects

Tebipenem pivoxil hydrobromide (TBP-PI-HBr) is an orally available prodrug of tebipenem (TBP), a carbapenem with in vitro activity against multidrug-resistant Gram-negative pathogens. This study evaluated the effects of single therapeutic and supratherapeutic doses of TBP-PI-HBr on the heart rate-corrected QT interval (QTc) by assessing the concentration-QT interval relationship using exposure-response modeling. This was a randomized, double-blind, placebo- and active-controlled, single-dose, four-way crossover study. Subjects received single oral doses of TBP-PI-HBr at 600 and 1,200 mg, placebo, and positive control (moxifloxacin at 400 mg). Cardiodynamic electrocardiograms (ECGs) and blood samples were collected in each period. Twenty-four subjects were enrolled. TBP-PI-HBr had no clinically significant adverse effects on heart rate or ECG parameters. The model-predicted slope suggests that the baseline-corrected difference in heart rate from placebo was not importantly affected by plasma TBP concentrations, supporting the use of the QT interval corrected by Fridericia's method as an appropriate correction. The model-predicted difference in QTc at the mean maximum concentration (Cmax) for TBP had negative predicted values for each dose, and no QTc prolongation was detected following TBP-PI-HBr at 600 mg or 1,200 mg. Assay sensitivity was established with moxifloxacin at 400 mg. Exposure to TBP increased in a dose-dependent manner with 600- and 1,200-mg doses. The TBP area under the concentration-time curve from time zero to infinity and Cmax with the 1,200-mg dose were 1.8- and 1.3-fold greater, respectively, than those with the 600-mg dose. TBP-PI-HBr was generally safe and well tolerated, with no effect in QT interval prolongation.

Efficacy and safety of azithromycin in Covid-19 patients: A systematic review and meta-analysis of randomized clinical trials

Azithromycin (AZM) is commonly used in Covid‐19 patients based on low‐quality evidence, increasing the risk of developing adverse events and antimicrobial resistance. The current systematic review and meta‐analysis investigated the safety and efficacy of AZM in treating Covid‐19 patients using published randomized controlled trials. Google Scholar, PubMed, Scopus, Cochrane Library, Clinical Trials.gov, MEDLINE, bioRxiv and medRxiv were searched for relevant studies. The random‐effects model was used to pool estimates using the Paule–Mandel estimate for heterogeneity. The odds ratio and raw difference in medians were used for dichotomous and continuous outcomes, respectively. The analysis included seven studies with 8822 patients (median age, 55.8 years; 61% males). The risk of bias was assessed as ‘low’ for five of the seven mortality results and as ‘some concerns’ and ‘high’ in one trial each. There were 657/3100 (21.2%) and 1244/5654 (22%) deaths among patients randomized to AZM and standard of care, respectively. The use of AZM was not associated with mortality in Covid‐19 patients (OR = 0.96, 95% CI 0.88–1.05, p = 0.317 based on the random‐effect meta‐analysis). The use of AZM was not associated with need for invasive mechanical ventilation (OR = 0.96, 95% CI 0.49–1.87, p = 0.85) and length of stay (Δ = 1.11, 95% CI −2.08 to 4.31, p = 0.49). The results show that using AZM as routine therapy in Covid‐19 patients is not justified due to lack of efficacy and potential risk of bacterial resistance that is not met by an increased clinical benefit.

In vivo and in silico evaluations of survival and cardiac developmental toxicity of quinolone antibiotics in zebrafish embryos (Danio rerio)

Quinolones are ranked as the second most commonly used class of antibiotics in China, despite their adverse clinical and environmental effects. However, information on their cardiac developmental toxicity to zebrafish is limited. This study investigates the relationships between different quinolone structures and toxicity in zebrafish embryos using in vivo and in silico methods. All of the experimentally tested quinolones show cardiac developmental toxicity potential and present mortality and teratogenic effects in a dose-dependent manner. Theoretically, the acute toxicity values predicted using quantitative structure-toxicity relationship (QSTR) modeling based on previously reported LC₅₀ values are in good agreement with the in vivo results. Further investigation demonstrates that the hormetic concentration response of some quinolones may be related to methylation on the piperazine ring at the C-7 position. The amino group at the C-5 position, the methylated or ethylated piperazine group at the C-7 position, halogens at the C-8 position and a cyclopropyl ring at N1 position may be responsible for cardiac developmental toxicity. In terms of survival (key ecological endpoint), the naridine ring is more toxic than the quinoline ring. This combined approach can predict the acute and cardiac developmental toxicity of other quinolones and impurities.

Effect of ciprofloxacin vs levofloxacin on QTc-interval and dysglycemia in diabetic and non-diabetic patients

BACKGROUND

Levofloxacin and ciprofloxacin are more commonly used amongst fluoroquinolone class and the question of cardiac safety and glucose hemostasis of this class has been raised.

OBJECTIVE

To compare intravenous levofloxacin and ciprofloxacin regarding their risk on QTc prolongation and dysglycemia in diabetic and non-diabetic patients.

METHODS

A randomised prospective study at Beni-Suef university hospital was conducted on 200 adult patients over 6 months. The patients received intravenous levofloxacin 750mg once daily or ciprofloxacin 400mg twice daily. Electrocardiogram and fasting blood glucose were obtained from each patient before starting the antibiotic, 24 hours, 72 hours after the first dose, and 72 hours after antibiotics cessation.

RESULTS

The results of the current study showed the relative risk for QTc prolongation with levofloxacin was more than ciprofloxacin by about 4 and 1.5 times in diabetic and non-diabetic patients, respectively. The relative risk for dysglycemia with levofloxacin was 2.28 and 1.39 times more than ciprofloxacin in diabetic and non-diabetic patients, respectively.

CONCLUSION

The present study showed that the risk for QTc prolongation and hyperglycemia was greater with levofloxacin than ciprofloxacin in diabetic and non-diabetic patients. In addition, the risk for hypoglycemia was greater with levofloxacin than ciprofloxacin in non-diabetic patients.

Putting Crohn's on the MAP: Five Common Questions on the Contribution of Mycobacterium avium subspecies paratuberculosis to the Pathophysiology of Crohn's Disease

For decades, Mycobacterium avium subspecies paratuberculosis (MAP) has been linked to the pathogenesis of Crohn's disease. Despite many investigations and research efforts, there remains no clear unifying explanation of its pathogenicity to humans. Proponents argue Crohn's disease shares many identical features with a granulomatous infection in ruminants termed Johne's disease and similarities with ileo-cecal tuberculosis. Both are caused by species within the Mycobacterium genus. Sceptics assert that since MAP is found in individuals diagnosed with Crohn's disease as well as in healthy population controls, any association with CD is coincidental. This view is supported by the uncertain response of patients to antimicrobial therapy. This report aims to address the controversial aspects of this proposition with information and knowledge gathered from several disciplines, including microbiology and veterinary medicine. The authors hope that this discussion will stimulate further research aimed at confirming or refuting the contribution of MAP to the pathogenesis of Crohn's disease and ultimately lead to advanced targeted clinical therapies.

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.

Facile synthesis of ultrathin NiSnO3 nanoparticles for enhanced electrochemical detection of an antibiotic drug in water bodies and biological samples

The highly sensitive real-time detection of antibiotic drugs (nitrofurantoin; NFT) has drawn significant research attention due to the extensive use of antibiotics, which may cause serious threats to environment as well as living things.

Clarithromycin use and the risk of mortality and cardiovascular events: A systematic review and meta-analysis

Background

Although studies reported increased cardiovascular (CV) risks in patients treated with macrolides, the risks remain controversial among clarithromycin (CLR) users. We aimed to summarize the association between CLR use and the risks of mortality and CV events.

Methods

We searched PubMed, EMBASE, Web of Science, and the Cochrane Library for randomized controlled trials (RCTs) and observational studies with population exposed to CLR published until December 31^st, 2018. These studies reported either all-cause mortality (primary outcome) or CV adverse events (secondary outcomes) based on multivariate models. Effect measures were synthesized by study design and follow-up duration (long-term, ≥ 1 year; short-term, ≤ 3 months; and immediate, ≤ 2 weeks). This study has been registered on PROSPERO (ID: CRD42018089605).

Results

This meta-analysis included 13 studies (3 RCTs and 10 observational studies) and 8,351,815 subjects (1,124,672 cases and 7,227,143 controls). Overall, CLR use was not associated with increased long-term all-cause mortality (pooled rate ratio RR = 1.09, 95% CI = 0.91–1.32), either among patients with or without comorbidities of cardiovascular diseases. Comparing CLR users to placebo, there is no additional risks of cardiac mortality (pooled RR = 1.03, 95% CI = 0.53–2.01), acute myocardial infarction (pooled RR = 1.29, 95% CI = 0.98–1.68), and arrhythmia (pooled RR = 0.90, 95% CI = 0.62–1.32).

Conclusions

Our findings suggested no significant association between CLR use and subsequent long-term all-cause mortality, regardless having comorbidity of cardiovascular diseases or not. Further RCTs investigating the short-term CV risks of CLR use compared to alternative antibiotics are warranted, particularly in high-risk populations.

Cardiac events after macrolides or fluoroquinolones in patients hospitalized for community-acquired pneumonia: post-hoc analysis of a cluster-randomized trial

Background

Guidelines recommend macrolides and fluoroquinolones in patients hospitalized with community-acquired pneumonia (CAP), but their use has been associated with cardiac events. We quantified associations between macrolide and fluoroquinolone use and cardiac events in patients hospitalized with CAP in non-ICU wards.

Methods

This was a post-hoc analysis of a cluster-randomized trial as a cohort study; including patients with a working diagnosis of CAP admitted to non-ICU wards without a cardiac event on admission. We calculated cause-specific hazard ratio’s (HR’s) for effects of time-dependent macrolide and fluoroquinolone exposure as compared to beta-lactam monotherapy on cardiac events, defined as new or worsening heart failure, arrhythmia, or myocardial ischemia during hospitalization.

Results

Cardiac events occurred in 146 (6.9%) of 2107 patients, including heart failure (n = 101, 4.8%), arrhythmia (n = 53, 2.5%), and myocardial ischemia (n = 14, 0.7%). These occurred in 11 of 207 (5.3%), 18 of 250 (7.2%), and 31 of 277 (11.2%) patients exposed to azithromycin, clarithromycin, and erythromycin for at least one day, and in 9 of 234 (3.8%), 5 of 194 (2.6%), and 23 of 566 (4.1%) exposed to ciprofloxacin, levofloxacin, and moxifloxacin, respectively. HR’s for erythromycin, compared to beta-lactam monotherapy, on any cardiac event and heart failure were 1.60 (95% CI 1.09;2.36) and 1.89 (95% CI 1.22;2.91), respectively. HR’s for levofloxacin and moxifloxacin, compared to beta-lactam monotherapy, on any cardiac event were 0.40 (95% CI 0.18;0.87)and 0.56 (95% CI 0.36;0.87), respectively. Findings remained consistent after adjustment for confounders and/or in a sensitivity analysis of radiologically confirmed CAP (n = 1604, 76.1%).

Conclusions

Among patients with CAP hospitalized to non-ICU wards, erythromycin use was associated with a 68% increased risk of hospital-acquired cardiac events, mainly heart failure. Levofloxacin and moxifloxacin were associated with a lower risk of heart failure. Although our study does not fully exclude confounding bias, findings remained largely unchanged in crude, adjusted, and sensitivity analyses. These findings may caution the use of erythromycin as empirical therapy in these patients.

Trial registration

The original trial was retrospectively registered under ClinicalTrials.gov Identifier NCT01660204 on August 8th, 2012.

Torsades de pointes and QT prolongation Associations with Antibiotics: A Pharmacovigilance Study of the FDA Adverse Event Reporting System

Introduction: Macrolides, linezolid, imipenem-cilastatin, fluoroquinolones, penicillin combinations, and ceftriaxone are known to be associated with Torsades de pointes/QT prolongation (TdP/QTP). Other antibiotics may also lead to TdP/QTP, but no study has systemically compared TdP/QTP associations for many available antibiotics. Objectives: The objective of this study was to evaluate the association between TdP/QTP and many available antibiotics using the FDA Adverse Event Report System (FAERS). Methods: FAERS reports from January 1, 2015 to December 31, 2017 were analyzed. The Medical Dictionary for Regulatory Activities (MedDRA) was used to identify TdP/QTP cases. We calculated the Reporting Odds Ratios (RORs) and corresponding 95% confidence intervals (95%CI) for the association between antibiotics and TdP/QTP. An association was considered to be statistically significant when the lower limit of the 95%CI was greater than 1.0. Results: A total of 2,042,801 reports (including 3,960 TdP/QTP reports) were considered, after inclusion criteria were applied. Macrolides had the greatest proportion of TdP/QTP reports. Of the 4,092 reports associated with macrolides, 108 reports (2.6%) were associated with TdP/QTP. Significant TdP/QTP RORs (95%CI) for the antibiotics were (in descending order): macrolides 14.32 (11.80-17.38), linezolid 12.41 (8.52-18.08), amikacin 11.80 (5.57-24.97), imipenem-cilastatin 6.61 (3.13-13.94), fluoroquinolones 5.68 (4.78-6.76), penicillin combinations 3.42 (2.35-4.96), and ceftriaxone 2.55 (1.41-4.62). Conclusion: This study confirms prior evidence for TdP/QTP associations with macrolides, linezolid, imipenem-cilastatin, fluoroquinolones, penicillin combinations, and ceftriaxone. This study also identifies a new association between amikacin and TdP/QTP.

The burden of community-acquired bacterial pneumonia in the era of antibiotic resistance

INTRODUCTION

Community-acquired pneumonia (CAP) is a significant global health problem and leading cause of death and hospitalization in both the US and abroad. Increasing macrolide resistance among Streptococcus pneumoniae and other pathogens results in a greater disease burden, along with changing demographics and a higher preponderance of comorbid conditions. Areas covered: This review summarizes current data on the clinical and economic burden of CAP, with particular focus on community-acquired bacterial pneumonia (CABP). Incidence, morbidity and mortality, and healthcare costs for the US and other regions of the world are among the topics covered. Major factors that are believed to be contributing to the increased impact of CABP, including antimicrobial resistance, the aging population, and the incidence of comorbidities are discussed, as well as unmet needs in current CABP management. Expert commentary: The clinical and economic burden of CABP is staggering, far-reaching, and expected to increase in the future as new antibiotic resistance mechanisms emerge and the world's population ages. Important measures must be initiated to stabilize and potentially decrease this burden. Urgent needs in CABP management include the development of new antimicrobials, adjuvant therapies, and rapid diagnostics.

The risk of cardiac events in patients who received concomitant levofloxacin and amiodarone

OBJECTIVES

Levofloxacin and amiodarone are both known to prolong the QT interval. This study was conducted to estimate the risk of cardiac events in patients receiving concomitant levofloxacin and amiodarone.

METHODS

The study included patients who were admitted to a large academic community medical center from 1/2012 to 12/2015 and received both levofloxacin and amiodarone at some point during their hospitalization. Patients received concomitant or non-concomitant levofloxacin and amiodarone during hospitalization. The primary outcome was the occurrence of cardiac events during therapy. The secondary outcome was the proportion of patients with an electrocardiogram performed before and after initiation of therapy. Odds ratios for cardiac events were calculated using a multivariable logistic regression model with and without adjusting for the study variables. The concomitant group was further evaluated for predictors of the primary outcome using multivariable logistic regression.

RESULTS

This study included 240 patients, 164 (68.3%) of whom received concomitant levofloxacin and amiodarone. Concomitant medication therapy was associated with a greater than six-fold increased risk of cardiac events after adjusting for the study variables (Odds Ratio=6.20; 95% Confidence Interval=1.34-28.62).

CONCLUSIONS

Patients receiving concomitant amiodarone and levofloxacin experienced a five-fold increase in cardiac events compared to patients given either medication alone.

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.

Potential Drug-Drug Interactions with Antimicrobials in Hospitalized Patients: A Multicenter Point-Prevalence Study

Background

Improper use of antimicrobials can cause adverse drug events and high costs. The purpose of this study was to investigate the frequency and potential drug–drug interactions associated with antimicrobials among hospitalized patients.

Material/Methods

This study was conducted on the same day in 5 different hospitals in Turkey. We included patients aged ≥18 years who received at least 1 antimicrobial drug and at least 1 of any other drug. The Micromedex^® online drug reference system was used to control and describe the interactions. Drug interactions were classified as contraindicated, major, moderate, and minor.

Results

Potential drug–drug interactions with antimicrobials were 26.4% of all interactions. Five (42%) of 12 contraindicated interactions and 61 (38%) of 159 major interactions were with antimicrobials. Quinolones, triazoles, metronidazole, linezolid, and clarithromycin accounted for 173 (25.7%) of 673 prescribed antimicrobials, but were responsible for 141 (92.1%) of 153 interactions. In multivariate analysis, number of prescribed antimicrobials (odds ratio: 2.3001, 95% CI: 1.6237–3.2582), number of prescribed drugs (odds ratio: 1.2008, 95% CI: 1.0943–1.3177), and hospitalization in the university hospital (odds ratio: 1.7798, 95% CI: 1.0035–3.1564) were independent risk factors for developing drug interactions.

Conclusions

Due to risk of drug interactions, physicians should be more cautious when prescribing antimicrobials, particularly when prescribing quinolones, linezolid, azoles, metronidazole, and macrolides.

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.

Antimicrobials and QT prolongation

Solithromycin, a ketolide/macrolide antibiotic, has recently been reported to be free of the expected QT-prolonging effect of macrolides. It appears that its keto substitution provides a structural basis for this observation, as the other two tested ketolides also have minimal QT effect.Among non-cardiovascular therapies, antimicrobials probably carry the greatest potential to cause cardiac arrhythmias. This is a result of their propensity to bind to the delayed rectifier potassium channel, IKr, inducing QT prolongation and risk of torsades de pointes ventricular tachycardia, their frequent interference with the metabolism of other QT prolongers and their susceptibility to metabolic inhibition by numerous commonly used drugs.Unfortunately, there is evidence that medical practitioners do not take account of the QT/arrhythmia risk of antimicrobials in their prescribing practices. Education on this topic is sorely needed. When a macrolide is indicated, a ketolide should be considered in patients with a QT risk.

Persistent ventricular bigeminy during anesthesia in pediatric patients: a case report of an 11-year-old child

An 11-year-old male child with fractures in both bones in his left forearm presented for open reduction and internal fixation. The pre-anesthetic check-up and investigations did not reveal any pre-existing underlying cardio-respiratory disease. The patient had an uneventful peri-operative period during the operation and was comfortable without any anxiety or restlessness. After an uneventful induction and intubation as per routine protocol, the patient received 600 mg of amoxicillin+clavunate intravenously as an antibiotic. After 3 min, the patient developed persistent ventricular bigeminy with intermittent sinus rhythm, which returned to normal after 20 min. Open reduction and internal fixation of the fractures in both bones were done. Extubation and the post-op course were uneventful. To rule out the cause of arrhythmia, ECG, 2D-ECHO and serum electrolyte evaluation were done, however the results came back as normal. Many days later, the patient fell again on the same arm and revisited the ortho operation theatre for revision surgery. As the child was very cooperative and calm, he was given a supraclavicular block after proper counseling. Thirty minutes before tourniquet inflation as a routine method, 600 mg of amoxicillin+clavunate was administered. After 5 min, the patient developed persistent ventricular bigeminy. After 1 h, the child complained of chest pain and had redness of eyes and was restless. This was managed with 100% oxygen and an injection of 150 mg amiodarone intravenously. Surgery was postponed for further stabilization and optimization. Serum electrolytes were normal. The child was observed in the surgical intensive care unit with continuous ECG monitoring. Ventricular bigeminy with intermittent sinus rhythm persisted for 3 days. This was managed with metoprolol 12.5 mg BD and amiodarone 100 mg OD tablets. The opinion of a pediatric cardiologist was obtained and repeated 2D-ECHO results revealed no abnormality. After 5 days, the patient was discharged and surgery was rescheduled for 2 weeks later with continuation of metaprolol and amiodarone tablets. On the fourth occasion we avoided the injection of amoxicillin+clavunate and all anesthetic drugs, which might contribute to cardiac arrhythmia. The peri-operative period was uneventful. An in-depth discussion of the case and ventricular dysrhythmias in the pediatric population is emphasized in this case report.

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.

Hypokalemia during antibiotic treatment for bone and joint infections

PURPOSE

During treatment of bone and joint infections (BJIs) with multiple antibiotic therapy, hypokalemia has been reported as a rare side effect. The aim of this study was to evaluate incidence and risk factors for hypokalemia in a cohort of patients treated with multidrug therapy for BJIs, in a single center.

METHODS

We retrospectively reviewed 331 clinical files of 150 consecutive patients (65% males; median age 59 years, 95% CI 55-62) admitted repeatedly to our Osteomyelitis Department for treatment of chronic BJIs. Besides surgical debridement, patients received a combination of oral and intravenous antibiotics. Routine laboratory tests were performed at admittance and repeated at least weekly. Possible hypokalemia risk factors were recorded and analyzed.

RESULTS

Progressive kalemia reduction occurred in > 39% of patients during hospitalization; prevalence of marked hypokalemia (K ⁺ < 3.5 mEq/l) increased from 5% at admission to 11% (up to 22%) at day 14. Correlated factors were: age ≥ 68 years (p = 0.033), low serum albumin (p = 0.034), treatment with vancomycin (p < 0.001), rifampicin (p = 0.017) and ciprofloxacin (p < 0.001) and use of thiazide (p = 0.007) or loop diuretics (p = 0.029 for K ⁺ < 3.5 mEq/l). At multivariate regression analysis, the main determinants of hypokalemia were simultaneous use of diuretics (p = 0.007) and older age (p < 0.049).

CONCLUSIONS

Appearance of severe hypokalemia is a frequent event among patients treated for BJIs with multiple antibiotic therapy, when this is prescribed in older age patients and associated with simultaneous use of diuretics. Due to possible increase in mortality risk in the short term, particular caution should be paid during intensive antibiotic treatment in these groups of patients.

Emergency department approach to QTc prolongation

QTc prolongation has been associated with increased risk of developing ventricular tachydysrhythmias, particularly Torsades de Pointes (TdP). QTc prolongation is influenced by many factors including congenital causes, heart rate, metabolic imbalances, and pharmacotherapy. Several commonly used medications in the emergency department (ED), such as antipsychotics and antiemetics, are known to prolong the QT interval. In addition, ED patients may present with conditions that may predispose them to QTc prolongation, such as drug overdose or hypokalemia, which can further complicate management. ED providers should not only be aware of which medications have these effects, but must also thoroughly investigate any pertinent patient history that may contribute to QTc prolongation. This review discusses commonly encountered medications that are associated with QTc prolongation, the mechanisms by which they prolong the QTc interval, and other factors that may influence ED medication administration and management.

Guidelines for the prevention and treatment of travelers' diarrhea: a graded expert panel report

BACKGROUND

: Travelers' diarrhea causes significant morbidity including some sequelae, lost travel time and opportunity cost to both travelers and countries receiving travelers. Effective prevention and treatment are needed to reduce these negative impacts.

METHODS

: This critical appraisal of the literature and expert consensus guideline development effort asked several key questions related to antibiotic and non-antibiotic prophylaxis and treatment, utility of available diagnostics, impact of multi-drug resistant (MDR) colonization associated with travel and travelers' diarrhea, and how our understanding of the gastrointestinal microbiome should influence current practice and future research. Studies related to these key clinical areas were assessed for relevance and quality. Based on this critical appraisal, guidelines were developed and voted on using current standards for clinical guideline development methodology.

RESULTS

: New definitions for severity of travelers' diarrhea were developed. A total of 20 graded recommendations on the topics of prophylaxis, diagnosis, therapy and follow-up were developed. In addition, three non-graded consensus-based statements were adopted.

CONCLUSIONS

: Prevention and treatment of travelers' diarrhea requires action at the provider, traveler and research community levels. Strong evidence supports the effectiveness of antimicrobial therapy in most cases of moderate to severe travelers' diarrhea, while either increasing intake of fluids only or loperamide or bismuth subsalicylate may suffice for most cases of mild diarrhea. Further studies are needed to address knowledge gaps regarding optimal therapies, the individual, community and global health risks of MDR acquisition, manipulation of the microbiome in prevention and treatment and the utility of laboratory testing in returning travelers with persistent diarrhea.

Raising awareness of bronchiectasis in primary care: overview of diagnosis and management strategies in adults

Bronchiectasis is a chronic lung disease characterised by recurrent infection, inflammation, persistent cough and sputum production. The disease is increasing in prevalence, requiring a greater awareness of the disease across primary and secondary care. Mild and moderate cases of bronchiectasis in adults can often be managed by primary care clinicians. Initial assessments and long-term treatment plans that include both pharmacological and non-pharmacological treatments, however, should be undertaken in collaboration with a secondary care team that includes physiotherapists and specialists in respiratory medicine. Bronchiectasis is often identified in patients with other lung diseases, such as chronic obstructive pulmonary disease, asthma, and in a lesser but not insignificant number of patients with other inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel disease. Overall goals of therapy are to prevent exacerbations, improve symptoms, improve quality of life and preserve lung function. Prompt treatment of exacerbations with antibiotic therapy is important to limit the impact of exacerbations on quality of life and lung function decline. Patient education and cooperation with health-care providers to implement treatment plans are key to successful disease management. It is important for the primary care provider to work with secondary care providers to develop an individualised treatment plan to optimise care with the goal to delay disease progression. Here, we review the diagnosis and treatment of bronchiectasis with a focus on practical considerations that will be useful to primary care.

Targeted Cancer Therapies and QT Interval Prolongation: Unveiling the Mechanisms Underlying Arrhythmic Complications and the Need for Risk Stratification Strategies

The care and treatment of cancer patients has significantly changed in the last decade with a remarkable shift towards novel targeted therapies. These promising new drugs may represent effective and potentially life-saving therapeutic options in cancer patients, but are also emerging in the cardiotoxicity scenario for their arrhythmogenic potential due to their QT-prolonging activity. In this article we review the mechanisms underlying drug-induced QT interval prolongation and the classes of anticancer-targeted therapies most frequently responsible for this adverse event, with a particular focus on tyrosine kinase-targeting molecules. Since up to 49 % of serious adverse drug reactions (ADRs) and 58 % of potentially fatal ADRs may not appear on initial drug safety labels, we also review and discuss data from the post-marketing VigiBase^® safety reporting system, the World Health Organization's global database of ADRs. Finally, we discuss arrhythmic risk stratification and prevention strategies in the complex multiple-risk setting of cancer patients, paying particular attention to drug-drug interactions with common antimicrobial, psychotropic and antiemetic supportive care, and we also provide an electrocardiographic QT monitoring algorithm for patients who are candidates for targeted cancer therapies.

Risk of cardiovascular events, arrhythmia and all-cause mortality associated with clarithromycin versus alternative antibiotics prescribed for respiratory tract infections: a retrospective cohort study

OBJECTIVE

To determine whether treatment with clarithromycin for respiratory tract infections was associated with an increased risk of cardiovascular (CV) events, arrhythmias or all-cause mortality compared with other antibiotics.

DESIGN

Retrospective cohort design comparing clarithromycin monotherapy for lower (LRTI) or upper respiratory tract infection (URTI) with other antibiotic monotherapies for the same indication.

SETTING

Routine primary care data from the UK Clinical Practice Research Datalink and inpatient data from the Hospital Episode Statistics (HES).

PARTICIPANTS

Patients aged ≥35 years prescribed antibiotic monotherapy for LRTI or URTI 1998-2012 and eligible for data linkage to HES.

MAIN OUTCOME MEASURES

The main outcome measures were: adjusted risk of first-ever CV event, within 37 days of initiation, in commonly prescribed antibiotics compared with clarithromycin. Secondarily, adjusted 37-day risks of first-ever arrhythmia and all-cause mortality.

RESULTS

Of 700 689 treatments for LRTI and eligible for the CV analysis, there were 2071 CV events (unadjusted event rate: 29.6 per 10 000 treatments). Of 691 998 eligible treatments for URTI, there were 688 CV events (9.9 per 10 000 treatments). In LRTI and URTI, there were no significant differences in CV risk between clarithromycin and all other antibiotics combined: OR=1.00 (95% CI 0.82 to 1.22) and 0.82 (0.54 to 1.25), respectively. Adjusted CV risk in LRTI versus clarithromycin ranged from OR=1.42 (cefalexin; 95% CI 1.08 to 1.86) to 0.92 (doxycycline; 0.64 to 1.32); in URTI, from 1.17 (co-amoxiclav; 0.68 to 2.01) to 0.67 (erythromycin; 0.40 to 1.11). Adjusted mortality risk versus clarithromycin in LRTI ranged from 0.42 to 1.32; in URTI, from 0.75 to 1.43. For arrhythmia, adjusted risks in LRTI ranged from 0.68 to 1.05; in URTI, from 0.70 to 1.22.

CONCLUSIONS

CV events were more likely after LRTI than after URTI. When analysed by specific indication, CV risk associated with clarithromycin was no different to other antibiotics.

The Use of Systemic and Topical Fluoroquinolones

Appropriate prescribing practices for fluoroquinolones, as well as all antimicrobial agents, are essential as evolving resistance patterns are considered, additional treatment indications are identified, and the toxicity profile of fluoroquinolones in children has become better defined. Earlier recommendations for systemic therapy remain; expanded uses of fluoroquinolones for the treatment of certain infections are outlined in this report. Prescribing clinicians should be aware of specific adverse reactions associated with fluoroquinolones, and their use in children should continue to be limited to the treatment of infections for which no safe and effective alternative exists or in situations in which oral fluoroquinolone treatment represents a reasonable alternative to parenteral antimicrobial therapy.

Electrocardiographic Effects of a Supratherapeutic Dose of Oritavancin

The purpose of this study was to measure oritavancin's electrocardiographic effects at a supratherapeutic dose of 1600 mg given intravenously (IV) over 3 hours. A cohort of 150 healthy volunteers were randomized to receive placebo, oritavancin, or oral moxifloxacin 400 mg in a parallel designed thorough QT study. A supratherapeutic mean maximum oritavancin concentration (C_max ) of 232 μg/mL was achieved. There was no significant effect on baseline and placebo corrected (dd) QTcF, QRS, or heart rate; ddPR was slightly increased at most time points, with a maximum mean change of 7.7 milliseconds 1 hour after infusion. Linear PK-PD modeling predicted a 3.2-millisecond change in the PR interval for the C_max (138 μg/mL) observed in pivotal phase 3 studies after 1200 mg of oritavancin. Moxifloxacin produced the expected increase in ddQTcF, validating assay sensitivity. At plasma concentrations above the clinical exposures of oritavancin, no clinically or statistically significant effect on QTcF, QRS, or heart rate was observed. The increase in PR is considered clinically insignificant, given the rapid decline in initial plasma concentration of oritavancin after infusion and the expected lower C_max in patients. A therapeutic 1200-mg single dose of oritavancin is not anticipated to cause any clinically significant effect on cardiac electrophysiology.

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.

Proarrhythmic and Torsadogenic Effects of Potassium Channel Blockers in Patients

The most common arrhythmia requiring drug treatment is atrial fibrillation (AF), which affects 2 to 5 million Americans and continues to be a major cause of morbidity and increased mortality. Despite recent advances in catheter-based and surgical therapies, antiarrhythmic drugs continue to be the mainstay of therapy for most patients with symptomatic AF. However, many antiarrhythmics block the rapid component of the cardiac delayed rectifier potassium current (IKr) as a major mechanism of action, and marked QT prolongation and pause-dependent polymorphic ventricular tachycardia (torsades de pointes) are major class toxicities.

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.

Prophylactic Azithromycin Therapy After Lung Transplantation: Post hoc Analysis of a Randomized Controlled Trial

Prophylactic azithromycin treatment has been demonstrated to improve freedom from bronchiolitis obliterans syndrome (BOS) 2 years after lung transplantation (LTx). In the current study, we re-evaluated the long-term effects of this prophylactic approach in view of the updated classification system for chronic lung allograft dysfunction (CLAD). A retrospective, intention-to-treat analysis of a randomized controlled trial comparing prophylactic treatment with placebo (n = 43) versus azithromycin (n = 40) after LTx was performed. Graft dysfunction (CLAD), graft loss (retransplantation, mortality), evolution of pulmonary function and functional exercise capacity were analyzed 7 years after inclusion of the last study subject. Following LTx, 22/43 (51%) patients of the placebo group and 11/40 (28%) patients of the azithromycin group ever developed CLAD (p = 0.043). CLAD-free survival was significantly longer in the azithromycin group (p = 0.024). No difference was present in proportion of obstructive versus restrictive CLAD between both groups. Graft loss was similar in both groups: 23/43 (53%) versus 16/40 (40%) patients (p = 0.27). Long-term pulmonary function and functional exercise capacity were significantly better in the azithromycin group (p < 0.05). Prophylactic azithromycin therapy reduces long-term CLAD prevalence and improves CLAD-free survival, pulmonary function, and functional exercise capacity after LTx.

The Value of Macrolide-Based Regimens for Community-Acquired Pneumonia

Macrolide antimicrobials are commonly prescribed, specifically for the treatment of respiratory tract infections. Although still effective, the development of widespread macrolide resistance has limited their use. Aside from their antimicrobial effects, macrolides are also known to possess immune-modulatory properties which may confer a survival benefit in both acute and chronic inflammatory states. This review discusses the efficacy, potential mechanisms, and adverse effects of macrolide therapy specifically in community-acquired pneumonia in outpatients, hospitalized ward patients, and those requiring intensive care unit admission. Challenges for ongoing research in this field are discussed and treatment recommendations offered.

Rare Incidence of Ventricular Tachycardia and Torsades de Pointes in Hospitalized Patients With Prolonged QT Who Later Received Levofloxacin: A Retrospective Study

OBJECTIVE

To determine the incidence of ventricular tachycardia and ventricular fibrillation in patients with prolonged corrected QT interval (QTc) who received levofloxacin through retrospective chart review at a tertiary care teaching hospital in the United States.

PATIENTS AND METHODS

We selected 1004 consecutive hospitalized patients with prolonged QTc (>450 ms) between October 9, 2009 and June 12, 2012 at our institution. Levofloxacin was administered orally and/or intravenously and adjusted to renal function in the inpatient setting. The primary outcome measure was sustained ventricular tachycardia recorded electrocardiographically.

RESULTS

With a median time from the start of levofloxacin use to hospital discharge (or death) of 4 days (range, 1-94 days), only 2 patients (0.2%; 95% CI, 0.0%-0.7%) experienced the primary outcome of sustained ventricular tachycardia after the initiation of levofloxacin use.

CONCLUSION

In this study, the short-term risk for sustained ventricular tachycardia in patients with a prolonged QTc who subsequently received levofloxacin was very rare. These results suggest that levofloxacin may be a safe option in patients with prolonged QTc; however, studies with longer follow-up are needed.