QTc prolongation during ciprofloxacin and fluconazole combination therapy: prevalence and associated risk factors

Onychomycosis: Old and New

Onychomycosis is a common chronic fungal infection of the nail that causes discoloration and/or thickening of the nail plate. Oral agents are generally preferred, except in the case of mild toenail infection limited to the distal nail plate. Terbinafine and itraconazole are the only approved oral therapies, and fluconazole is commonly utilized off-label. Cure rates with these therapies are limited, and resistance to terbinafine is starting to develop worldwide. In this review, we aim to review current oral treatment options for onychomycosis, as well as novel oral drugs that may have promising results in the treatment of onychomycosis.

QTc prolongation during levofloxacin and triazole combination chemoprophylaxis: Prevalence and predisposing risk factors in a cohort of hematopoietic cell transplantation recipients

BACKGROUND

QTc interval prolongation has been reported when combining fluoroquinolones and triazoles for chemoprophylaxis in cancer patients. Herein, we aimed to identify the prevalence and contributing factors to QTc prolongation in hematopoietic cell transplantation (HCT) recipients who received these agents during the neutropenic phase.

METHODS

This is a retrospective medical chart review conducted at a university hospital in Lebanon from 2017 to 2020. It included all adult HCT inpatients on antimicrobial prophylaxis with fluoroquinolones and triazoles and whose baseline ECG monitoring done prior to chemoprophylaxis administration, then on day-3 and day-6 of therapy, were available.

RESULTS

Overall, 68 HCT recipients met our inclusion criteria, of which 22% developed QTc prolongation. Based on bivariate analysis, female gender contributed to QTc prolongation (P = 0.001). There was a trend to QTc prolongation in patients with predisposing thyroid disease (P = 0.12), grade 2 vomiting and diarrhea (P = 0.16, P = 0.46, respectively), baseline hypokalemia (P = 0.18) and hypocalcemia (P = 0.3), hypomagnesemia on day-3 (P = 0.21) and day-6 hyponatremia (P = 0.36). Patients receiving two or more drugs with a known or probable risk of QTc prolongation (other than the fluoroquinolone/ triazole combination) were more prone to experience a prolonged QTc interval (P = 0.09). None of the patients that had QTc prolongation died or developed serious arrhythmias.

CONCLUSION

The prevalence of QTc prolongation was 22% among HCT recipients on fluoroquinolone and triazole prophylaxis, yet we did not identify any independent risk factors for this issue. None of the patients that had QTc interval prolongation died or developed serious arrhythmias.

Dynamics of the QTc interval over a 24-h dose interval after start of intravenous ciprofloxacin or low-dose erythromycin administration in ICU patients

QTc interval prolongation is an adverse effect associated with the use of fluoroquinolones and macrolides. Ciprofloxacin and erythromycin are both frequently prescribed QTc-prolonging drugs in critically ill patients. Critically ill patients may be more vulnerable to developing QTc prolongation, as several risk factors can be present at the same time. Therefore, it is important to know the QTc-prolonging potential of these drugs in the intensive care unit (ICU) population. The aim of this study was to assess the dynamics of the QTc interval over a 24-hour dose interval during intravenous ciprofloxacin and low-dose erythromycin treatment. Therefore, an observational study was performed in ICU patients (≥18 years) receiving ciprofloxacin 400 mg t.i.d. or erythromycin 100 mg b.i.d. intravenously. Continuous ECG data were collected from 2 h before to 24 h after the first administration. QT-analyses were performed using high-end holter software. The effect was determined with a two-sample t-test for clustered data on all QTc values. A linear mixed model by maximum likelihood was applied, for which QTc values were assessed for the available time intervals and therapy. No evident effect over time on therapy with ciprofloxacin and erythromycin was observed on QTc time. There was no significant difference (p = 0.22) in QTc values between the ciprofloxacin group (mean 393 ms) and ciprofloxacin control group (mean 386 ms). The erythromycin group (mean 405 ms) and erythromycin control group (mean 404 ms) neither showed a significant difference (p = 0.80). In 0.6% of the registrations (1.138 out of 198.270 samples) the duration of the QTc interval was longer than 500 ms. The index groups showed slightly more recorded QTc intervals over 500 ms. To conclude, this study could not identify differences in the QTc interval between the treatments analyzed.

Risk factors and predictors of QTc prolongation in critically ill Chinese patients

BACKGROUND

To recognize and validate the predictor of risk factors for ICU patients with QTc intervals ≥500 ms.

METHODS

We retrospectively reviewed 160 ICU patients with their medical electronic records including all demographic data, diagnosis measurements, ECGs and medication from March 1, 2018 to December 1, 2018. All information of patients' baseline, comorbidities, electrolytes and Long QT syndrome (LQTS)-inducing medications of patients with QT interval corrected (QTc) ≥ 500 ms (n = 80) and <500 ms (n = 80) were collected and analyzed using univariate and multivariate analyses to find predictors.

RESULTS

Comparing to patients with QTc < 500 ms, patients with QTc ≥ 500 ms had increased SOFA (P = 0.010) and APACHE II scores (P = 0.002), longer lengths of ICU stays (P < 0.001), greater incidence of congestive heart failure (P = 0.005) and more preset risk factors (P < 0.001). The frequency of administration of mosapride (P = 0.015), amiodarone (P = 0.027) and number of combined LQTS-inducing medications (P = 0.012) were greater in patients with QTc ≥ 500 ms than in those with QTc < 500 ms. But after multivariate analysis, we found that risk factors related to a QTc ≥ 500 ms were only congestive heart failure (OR: 5.28), number of combined LQTS-inducing medications (OR: 1.60) and APACHE II score (OR: 1.08).

CONCLUSIONS

For critically ill patients, congestive heart failure, number of combined LQTS-inducing medications and APACHE II score are proved as risk factors associated with QTc > 500 ms.

Management of fever and neutropenia in the adult patient with acute myeloid leukemia

INTRODUCTION

Febrile neutropenia represents one of the most common treatment-associated complications in the management of acute myeloid leukemia (AML) and is considered an oncologic emergency. Rapid and detailed workup as well as the initiation of empiric broad-spectrum antibiotic therapy are critical to avoid sepsis and to reduce mortality. Although a definitive source of infection is frequently not identified, the severely immunosuppressed status of the AML patient undergoing cytotoxic therapy results in a high risk for a wide array of bacterial, fungal, and viral etiologies.

AREAS COVERED

The authors herein review the diagnostic and therapeutic approach to the neutropenic leukemia patient based on the current knowledge. Special consideration is given to the rapidly changing therapeutic landscape in AML, creating new challenges in the management of infectious complications.

EXPERT OPINION

Multidrug-resistant organisms pose a major challenge in the management of neutropenic fever patients with hematologic malignancies - including AML. Future directions to improve outcomes demand innovative treatment approaches as well as advances in biomarker research to facilitate diagnosis and disease monitoring. Recent achievements in AML-targeted therapy led to an increased incidence of differentiation syndrome, a potentially life-threatening side effect that frequently resembles clinical infection and requires prompt recognition and aggressive intervention.

Improving antibacterial prescribing safety in the management of COPD exacerbations: systematic review of observational and clinical studies on potential drug interactions associated with frequently prescribed antibacterials among COPD patients

Background

Guidelines advise the use of antibacterials (ABs) in the management of COPD exacerbations. COPD patients often have multiple comorbidities, such as diabetes mellitus and cardiac diseases, leading to polypharmacy. Consequently, drug–drug interactions (DDIs) may frequently occur, and may cause serious adverse events and treatment failure.

Objectives

(i) To review DDIs related to frequently prescribed ABs among COPD patients from observational and clinical studies. (ii) To improve AB prescribing safety in clinical practice by structuring DDIs according to comorbidities of COPD.

Methods

We conducted a systematic review by searching PubMed and Embase up to 8 February 2018 for clinical trials, cohort and case–control studies reporting DDIs of ABs used for COPD. Study design, subjects, sample size, pharmacological mechanism of DDI and effect of interaction were extracted. We evaluated levels of DDIs and quality of evidence according to established criteria and structured the data by possible comorbidities.

Results

In all, 318 articles were eligible for review, describing a wide range of drugs used for comorbidities and their potential DDIs with ABs. DDIs between ABs and co-administered drugs could be subdivided into: (i) co-administered drugs altering the pharmacokinetics of ABs; and (ii) ABs interfering with the pharmacokinetics of co-administered drugs. The DDIs could lead to therapeutic failures or toxicities.

Conclusions

DDIs related to ABs with clinical significance may involve a wide range of indicated drugs to treat comorbidities in COPD. The evidence presented can support (computer-supported) decision-making by health practitioners when prescribing ABs during COPD exacerbations in the case of co-medication.

The Risk of QTc-Interval Prolongation in Breast Cancer Patients Treated with Tamoxifen in Combination with Serotonin Reuptake Inhibitors

PURPOSE

Antidepressants like the serotonin reuptake inhibitors (SRIs) are often used concomitantly with tamoxifen (e.g. for treatment of depression). This may lead to an additional prolongation of the QTc-interval, with an increased risk of cardiac side effects. Therefore we investigated whether there is a drug-drug interaction between tamoxifen and SRIs resulting in a prolonged QTc-interval.

METHODS

Electrocardiograms (ECGs) of 100 patients were collected at steady state tamoxifen treatment, with or without concomitant SRI co-medication. QTc-interval was manually measured and calculated using the Fridericia formula. Primary outcome was difference in QTc-interval between tamoxifen monotherapy and tamoxifen concomitantly with an SRI.

RESULTS

The mean QTc-interval was 12.4 ms longer when tamoxifen was given concomitantly with an SRI (95% CI:1.8-23.1 ms; P = 0.023). Prolongation of the QTc-interval was particularly pronounced for paroxetine (17.2 ms; 95%CI:1.4-33.0 ms; P = 0.04), escitalopram (12.5 ms; 95%CI:4.4-20.6 ms; P < 0.01) and citalopram (20.7 ms; 95%CI:0.7-40.7 ms; P = 0.047), where other agents like venlafaxine did not seem to prolong the QTc-interval. None of the patients had a QTc-interval of >500 ms.

CONCLUSIONS

Concomitant use of tamoxifen and SRIs resulted in a significantly higher mean QTc-interval, which was especially the case for paroxetine, escitalopram and citalopram. When concomitant administration with an SRI is warranted venlafaxine is preferred.

Drug-drug interactions in breast cancer patients treated with CDK4/6 inhibitors

CDK4/6 inhibitors are a new class of anticancer drugs used for the treatment of women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced or metastatic breast cancer with disease progression following endocrine therapy. Polypharmacy is a well-known problem in advanced cancer causing potential drug-drug interactions (DDIs), which, in turn, may limit the therapeutic value of CDK4/6 inhibitors. Therefore, understanding the mechanisms underlying potential DDIs in patients taking CDK4/6 inhibitors may be useful in decision-making processes and represent an important step towards treatment personalization. The present review is aimed at describing the potential DDIs that might occur in breast cancer patients receiving CDK4/6 inhibitors based on direct evidence from the literature and mechanistic considerations tailored on specific class of drugs used in combination.

Can Intradetrusor OnabotulinumtoxinA Injections Alter Heart Function in Patients with Cardiac Arrhythmia?

The prevalence of overactive bladder (OAB) increases with age and can be associated with other co-morbidities, such as cardiac arrhythmia. Unfortunately, commonly used anticholinergic drugs for OAB can affect the cardiovascular system, leading to tachycardia. However, there are no data, which consider the influence of intradetrusor onabotulinumtoxinA injections on heart function in idiopathic OAB patients. The aim of the present study was to evaluate the influence of intradetrusor onabotulinumtoxinA injections on electrocardiogram (ECG) parameters. Additionally, changes in ECG were analyzed in OAB patients without cardiac arrhythmia. Thirty-one patients with cardiac arrhythmia and 31 participants without irregular heart rate (HR) completed the study. ECG measurements were performed in supine positions 2 h before onabotulinumtoxinA injections, 1 h after treatment, and at 2 weeks of follow-up. At week 6, a phone-call survey was conducted to collect data about adverse events. OnabotulinumtoxinA injections were performed with rigid cystoscopy under local anesthesia. We did not observe any clinically significant changes in the analyzed ECG parameters between consecutive measurements. While a slight increase of HR was observed in patients without cardiac arrhythmia, it remained within normal range. Intravesical onabotulinumtoxinA injections are, hence, safe for female patients with cardiac arrhythmia and do not significantly influence changes in ECG.

QTc prolongation during ciprofloxacin and fluconazole combination therapy: prevalence and associated risk factors

AIM(S)

Ciprofloxacin and fluconazole combination therapy is frequently used as prophylaxis for, and treatment of, infections in patients with haematological malignancies. However, both drugs are known to prolong the heart rate-corrected QT (QTc) interval, which is a serious risk factor for torsade de pointes (TdP). Therefore, the aim of the current study was to assess the prevalence of QTc prolongation during ciprofloxacin and fluconazole use. The secondary objective was to determine associated risk factors of QTc prolongation in these patients.

METHODS

A prospective observational study was performed in patients admitted to the Erasmus University Medical Centre and treated with ciprofloxacin and fluconazole. A 12-lead electrocardiogram (ECG) was recorded at the estimated time to peak concentration (T_max ) for the last added drug. The main outcome was the proportion of patients with QTc prolongation during treatment. Data on the following potential risk factors were collected: patient characteristics, serum electrolyte levels, dosage of ciprofloxacin and fluconazole, renal and liver function and concomitant use of other QTc-prolonging drugs and cytochrome P450 3A4 inhibitors.

RESULTS

A total of 170 patients were included, of whom 149 (87.6%) were treated for haematological malignancies. The prevalence of QTc prolongation was 4.7%. No risk factors were found to be associated with QTc prolongation. The QTc interval increased by 10.7 ms [95% confidence interval (CI) 7.2, 14.1 ms] during ciprofloxacin and fluconazole combination therapy.

CONCLUSION

The prevalence of QTc prolongation in patients using ciprofloxacin and fluconazole is low compared with the prevalence in the general population, which varies from 5% to 11%. In addition, no risk factors were found. Given the low prevalence, routine ECG monitoring in patients on this therapy should be reconsidered.