Prescription of QT-prolonging drugs in a cohort of about 5 million outpatients

Short-term azithromycin use is associated with QTc interval prolongation in children with cystic fibrosis

BACKGROUND

Azithromycin is used for children with cystic fibrosis (CF) for its immunomodulatory and anti-inflammatory action. This study investigated the short-term alterations in QTc interval associated with azithromycin prophylaxis in pediatric patients with CF.

METHODS

This study included 121 patients with mild CF, of whom 76 received azithromycin (patient group) and 45 did not receive azithromycin (control group). The patient and control groups were categorized according to age as under 12 years of age and over 12 years of age. The first presentation measured all the patient and control groups at basic QTc time intervals. The QTc intervals of all patients were then remeasured systemically at 1, 3, and 6 months. Age categories and QTc intervals that were calculated at each month in the patient and control groups were compared statistically.

RESULTS

A statistically significant difference was detected in the patient group between the initial QTc interval time and the electrocardiogram (ECG) findings in the first and third months after prophylaxis treatment (p < 0.001; p = 0.01). However, no statistically significant difference was detected in the sixth month (p > 0.05) in all groups. Almost all of the children's QTc intervals were within normal range and within the safety zone (under 0.44 s). No statistically significant difference was detected in the control group between the initial ECG and the QTc intervals measured at 1, 3, and 6 months.

CONCLUSION

Short-term use of azithromycin prophylaxis in pediatric patients with mild CF slightly increased the QTc interval in the first and third months of follow-up. Nevertheless, all QTc interval changes fell within the safety zone. Notably, 1 month of follow-up treatment should be performed to check for any alteration in the QTc interval. If increased QTc interval duration is not detected in the first month, azithromycin prophylaxis can be safely prescribed.

Evaluating the prescribing and monitoring of medications associated with QTc-prolongation in the ambulatory care setting

RATIONALE

Little is known about the prescribing of medications with potential to cause QTc-prolongation in the ambulatory care settings. Understanding real-world prescribing of QTc-prolonging medications and actions taken to mitigate this risk will help guide strategies to optimize safety and appropriate prescribing among ambulatory patients.

OBJECTIVE

To evaluate the frequency of clinician action taken to monitor and mitigate modifiable risk factors for QTc-prolongation when indicated.

METHODS

This retrospective, cross-sectional study evaluated clinician action at the time of prescribing prespecified medications with potential to prolong QTc in adult patients in primary care. The index date was defined as the date the medication was ordered. Electronic health record (EHR) data were evaluated to assess patient, clinician and visit characteristics. Clinician action was determined if baseline or follow-up monitoring was ordered or if action was taken to mitigate modifiable risk factors (laboratory abnormalities or electrocardiogram [ECG] monitoring) within 48 h of prescribing a medication with QTc-prolonging risk. Descriptive statistics were used to describe current practice.

RESULTS

A total of 399 prescriptions were prescribed to 386 patients, with a mean age of 51 ± 18 years, during March 2021 from a single-centre, multisite health system. Of these, 17 (4%) patients had a known history of QTc-prolongation, 170 (44%) did not have a documented history of QTc-prolongation and 199 (52%) had an unknown history (no ECG documented). Thirty-nine patients (10%) had at least one laboratory-related risk factor at the time of prescribing, specifically hypokalemia (16 patients), hypomagnesemia (8 patients) or hypocalcemia (19 patients). Of these 39 patients with laboratory risk factors, only 6 patients (15%) had their risk acknowledged or addressed by a clinician. Additionally, eight patients' most recent QTc was ≥500 ms and none had an ECG checked at the time the prescription was ordered.

CONCLUSION

Despite national recommendations, medication monitoring and risk mitigation is infrequent when prescribing QTc-prolonging medications in the ambulatory care setting. These findings call for additional research to better understand this gap, including reasons for the gap and consequences on patient outcomes.

Pharmacist Reported Protocols for QTc Monitoring of Psychiatric Medications

Background Psychiatric medications, such as antipsychotics and antidepressants, are associated with QTc interval prolongation. There is currently no consensus best practice on how to mitigate this risk. This study aimed to collect and analyze information about methods used for QTc monitoring in patients taking psychiatric medications to better understand current practice. Methods An anonymous electronic survey was distributed on September 22, 2022, using a national psychiatric pharmacist organization email list. The survey closed on December 15, 2022. Descriptive statistics were used to analyze the multiple-choice questions. Qualitative analysis applying grounded theory for thematic analysis was performed for free response questions. Results A total of 48 initiated the survey. Of the respondents, 11.4% (5/44) reported that their institution had a formal protocol for monitoring QTc intervals in patients receiving psychiatric medications, while 32.4% (12/37) reported that their institution had an informal process. Out of those with a protocol or process, approximately half reported that it was drug-specific. Among the respondents, 88.6% (31/35) reported that there was a psychiatric clinical pharmacy specialist at their institution and 34.3% (12/35) reported that pharmacists could order an electrocardiogram (ECG). Major themes that emerged from the qualitative analysis included pharmacist-driven QTc monitoring, referring the patient to another provider for monitoring, and encountering significant barriers to monitoring. Conclusion A variety of methods are currently being employed to monitor QTc prolongation risk in patients taking psychiatric medications. Pharmacist authorization to order ECGs may be an opportunity to advance practice and improve care for this population. Further research is needed to more clearly understand best practices for QTc prolongation risk mitigation in patients receiving psychiatric medications.

Prevalence of QT-Prolonging Drug-Drug Interactions in Psychiatry: A Systematic Review and Meta Analysis

Background: Drug-drug interactions (DDIs) are considered an emerging threat to the patients if undetected. DDIs can prolong QT interval, leading to fatal ventricular arrhythmia. Antipsychotics and antidepressants prescribed commonly to psychiatric patients have the propensity to prolong QT interval and can precipitate Torsades de pointes (TdP). This review aimed to summarize the prevalence of QT interval prolonging DDIs in psychiatric patients. Methods: This meta-analysis was carried out following the MOOSE (Meta-analysis of Observational Studies in Epidemiology) statement. Databases like Pubmed/MEDLINE, Google Scholar and Research gate were scanned for English language papers. Indexed terms from Medical Subject (MeSH) and other search terms for "QT prolongation", "Drug interactions", and "Psychiatry" were used to identify the articles. All published articles available until the day of the collection were considered. Outcome measures were analyzed with meta package in R language. Results: A total of 5 studies were eligible for inclusion. From the included studies, QT-prolonging DDIs were found in 14806 patients out of 30122 patients. The prevalence of QT-prolonging DDIs in psychiatric patients was found to be 42% (95% confidence interval: 21%, 66%). The factors associated with potential drug-drug interactions were related to patient characteristics such as polypharmacy, age and comorbid disease. Conclusion: This review concluded that psychiatric patients were prescribed the drugs/drug combinations which can prolong QT interval and can cause adverse effects on the cardiovascular system. Hence, it is important to implement precautionary safety interventions, be vigilant and prevent QT prolongation and adverse cardiac effects in clinical practice.

Outpatient Parenteral Antibiotic Therapy in Older Adults

Outpatient parenteral antimicrobial therapy (OPAT) for older adults is a complex process that involves multiple stakeholders and care coordination, but it is a useful and patient-centered tool with opportunities for the treatment of complicated infections, improved patient satisfaction, and reduced health-care costs. Older age should not be an exclusion for OPAT but rather prompt the OPAT provider to thoroughly evaluate candidacy and safety. Amid the on-going COVID-19 pandemic, innovations in OPAT are needed to shepherd OPAT care into a more patient-centered, thoughtful practice, whereas minimizing harm to older patients from unnecessary health-care exposure and thus health-care associated infections.

Development in Prescriptions of Contraindicated and Potentially Harmful QT Interval-Prolonging Drugs in a Large Geriatric Inpatient Cohort From 2011 to 2021

Regulatory authorities put major emphasis on QT (interval)-prolonging properties of new molecular entities. Product information/Summaries of Product Characteristics (SmPCs) of multiple drugs contain warnings or contraindications regarding QT prolongation, e.g., on coadministration of QT-prolonging drugs (QT drugs). To characterize the development of the QT drug burden, we performed a trend analysis of prescriptions and co-prescriptions of QT drugs in a large geriatric inpatient cohort. The German SmPCs (status of 2014 and of 2021) and the year-wise listings in the CredibleMeds^® database from 2011 to 2021 were used as sources. There were 402,631 geriatric cases included. The group of QT drugs according to SmPCs in 2014, which must not be combined with other QT drugs, was less frequently involved in contraindicated co-prescriptions in 2021 compared with 2015 (3.0% (2.5-3.7%) of cases with at least one of those drugs in 2021 vs. 4.0% (3.5-4.5%) in 2015), with citalopram, escitalopram, and amiodarone involved in nearly 90% of the co-prescriptions. The number of CredibleMeds-QT-drugs per patient increased from 0.4 (SD=1.1) in 2011 to 1.8 (SD=3.9) in 2021. The percentage of contraindicated co-prescriptions of drugs with known risk for torsade de pointes according to CredibleMeds^® listings at the beginning of the respective years increased from 1.7% in 2011 to 6.1% in 2021. Considering the regularly updated CredibleMeds^® QT drugs list, the contraindicated co-prescriptions of QT drugs markedly increased in the last decade. If prescribers considered only the few most frequently (co-) prescribed QT drugs, then most of the medication errors regarding QT drugs could be prevented.

Management of opioid use disorder and associated conditions among hospitalized adults: A Consensus Statement from the Society of Hospital Medicine

Hospital-based clinicians frequently care for patients with opioid withdrawal or opioid use disorder (OUD) and are well-positioned to identify and initiate treatment for these patients. With rising numbers of hospitalizations related to opioid use and opioid-related overdose, the Society of Hospital Medicine convened a working group to develop a Consensus Statement on the management of OUD and associated conditions among hospitalized adults. The guidance statement is intended for clinicians practicing medicine in the inpatient setting (e.g., hospitalists, primary care physicians, family physicians, advanced practice nurses, and physician assistants) and is intended to apply to hospitalized adults at risk for, or diagnosed with, OUD. To develop the Consensus Statement, the working group conducted a systematic review of relevant guidelines and composed a draft statement based on extracted recommendations. Next, the working group obtained feedback on the draft statement from external experts in addiction medicine, SHM members, professional societies, harm reduction organizations and advocacy groups, and peer reviewers. The iterative development process resulted in a final Consensus Statement consisting of 18 recommendations covering the following topics: (1) identification and treatment of OUD and opioid withdrawal, (2) perioperative and acute pain management in patients with OUD, and (3) methods to optimize care transitions at hospital discharge for patients with OUD. Most recommendations in the Consensus Statement were derived from guidelines based on observational studies and expert consensus. Due to the lack of rigorous evidence supporting key aspects of OUD-related care, the working group identified important issues necessitating future research and exploration.

Use of Electrocardiogram Monitoring in Adult Patients Taking High-Risk QT Interval Prolonging Medicines in Clinical Practice: Systematic Review and Meta-analysis

Introduction

Electrocardiogram (ECG) monitoring is an important tool to detect and mitigate the risk of potentially fatal drug-induced QT prolongation and remains fundamental in supporting the quality use of high-risk QT interval prolonging medicines.

Objective

The aim of this systematic review was to determine the prevalence of baseline and/or follow-up ECG use in adult patients taking high-risk QT interval prolonging medicines in clinical practice.

Methods

CINAHL, Cochrane Library, Embase, PubMed, EThOS, OpenGrey and Proquest were searched for studies in adults that reported ECG use at baseline and/or at follow-up in relation to the initiation of a high-risk QT interval prolonging medicine in any clinical setting; either hospital or non-hospital. Two reviewers independently assessed the methodological quality of included studies. Proportional meta-analysis was conducted with all studies reporting baseline ECG use, before medicine initiation, and follow-up ECG use, within 30 days of medicine initiation.

Results

There was variability in baseline ECG use according to the practice setting. The prevalence of baseline ECG use for high-risk QT interval prolonging medicines was moderate to high in the hospital setting at 75.1% (95% CI 64.3–84.5); however, the prevalence of baseline ECG use was low in the non-hospital setting at 33.7% (95% CI 25.8–42.2). The prevalence of follow-up ECG use was low to moderate in the hospital setting at 39.2% (95% CI 28.2–50.8) and could not be determined for the non-hospital setting.

Conclusions

The use of ECG monitoring for high-risk QT interval prolonging medicines is strongly influenced by the clinical practice setting. Baseline ECG use occurs more in the hospital setting in comparison to the non-hospital setting. There is lower use of follow-up ECG in comparison to baseline ECG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-022-01215-x.

Risk assessment tools for QT prolonging pharmacotherapy in older adults: a systematic review

Purpose

Many drugs are associated with the risk of QT prolongation and torsades de pointes (TdP), and different risk assessment tools (RATs) are developed to help clinicians to manage related risk. The aim of this systematic review was to summarize the evidence of different RATs for QT prolonging pharmacotherapy.

Methods

A systematic review was conducted using PubMed and Scopus databases. Studies concerning risk assessment tools for QT prolonging pharmacotherapy, including older adults, were included. Screening and selection of the studies, data extraction, and risk of bias assessment were undertaken.

Results

A total of 21 studies were included, involving different risk assessment tools. Most commonly used tools were risk scores (n = 9), computerized physician order entry systems (n = 3), and clinical decision support systems (n = 6). The tools were developed mainly for physicians and pharmacists. Risk scores included a high number of risk factors, both pharmacological and non-pharmacological, for QT prolongation and TdP. The inclusion of patients’ risk factors in computerized physician order entry and clinical decision support systems varied.

Conclusion

Most of the risk assessment tools for QT prolonging pharmacotherapy give a comprehensive overview of patient-specific risks of QT prolongation and TdP and reduce modifiable risk factors and actual events. The risk assessment tools could be better adapted to different health information systems to help in clinical decision-making. Further studies on clinical validation of risk assessment tools with randomized controlled trials are needed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-022-03285-3.

Leading 20 drug-drug interactions, polypharmacy, and analysis of the nature of risk factors due to QT interval prolonging drug use and potentially inappropriate psychotropic use in elderly psychiatry outpatients

BACKGROUND

Psychotropic medications extend corrected QT (QTc) period in the electrocardiogram (ECG). Psychiatric patients exposed to ⩾1 psychotropic medication(s) represent a group with marked probability of drug-activated QTc-prolongation. Prolonged QTc interval in elderly patients (age > 60 years) is connected to greater risk of all-cause and coronary heart disease deaths. This study aimed at investigating pattern of utilization of QTc-interval protracting medications, QT-extending drug interactions, and prevalence of QTc-interval extending hazard factors in elderly patients.

METHODS

This was a cross-sectional, prospective study at the Psychiatry OPD at All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, India from 1 October 2017 to 30 August 2019 employing the pertinent prescriptions.

RESULTS

A total of 832 elderly patients (age 60 years or more) visiting the Psychiatry OPD during the aforementioned study duration were investigated. About 420 (50.5%) patients were males while 412 (49.5%) were females. Of the 832 patients, 588 (70.7%) were using interacting agents with capacity to produce TdP. Almost 1152 interacting torsadogenic medication pairs were unraveled. As per AzCERT/CredibleMeds Classification, 1016 (48.8%), 724 (34.8%), and 248 (12%) agents with potential to interact were identified with 'known', 'possible', and 'conditional risk of TdP', respectively. The common interacting medications belonged to antidepressant (288), proton pump inhibitor (364), antipsychotic (340), antinausea (184), antimicrobial (156), and H₂ receptor antagonist (60) therapeutic categories. The all-inclusive frequency of potentially inappropriate psychotropic (PIP) agents administered was 62% (1343/2166) with Beers Criteria 2019, and 46% (997/2166) with STOPP Criteria 2015.

CONCLUSION

Many geriatric patients were administered drugs and drug combinations with heightened proclivity toward QT-interval prolongation. Furthermore, reliable evidence-based online drug knowledge resources, such as AzCERT/CredibleMeds Drug Lists, Medscape Drug Interactions Checker, Epocrates Online Interaction Check, and Drugs.com Drug Interactions Checker, can facilitate clinical professionals in selecting drugs for psychiatric patients. A wise choice of medications is imperative to preclude serious adverse sequelae. Therefore, we need to exigently embrace precautionary safety means, be vigilant, and forestall QT-extension and TdP in clinical environments.

Antipsychotics cardiotoxicity: What's known and what's next

Chronic use of antipsychotic medications entails a dilemma between the benefit of alleviating psychotic symptoms and the risk of troubling, sometimes life-shortening adverse effects. Antipsychotic-induced cardiotoxicity is one of the most life-threatening adverse effects that raises widespread concerns. These cardiotoxic effects range from arrhythmia to heart failure in the clinic, with myocarditis/cardiomyopathy, ischemic injuries, and unexplained cardiac lesions as the pathological bases. Multiple mechanisms have been proposed to underlie antipsychotic cardiotoxicity. This review aims to summarize the clinical signs and pathological changes of antipsychotic cardiotoxicity and introduce recent progress in understanding the underlying mechanisms at both the subcellular organelle level and the molecular level. We also provide an up-to-date perspective on future clinical monitoring and therapeutic strategies for antipsychotic cardiotoxicity. We propose that third-generation antipsychotics or drug adjuvant therapy, such as cannabinoid receptor modulators that confer dual benefits — i.e., alleviating cardiotoxicity and improving metabolic disorders — deserve further clinical evaluation and marketing.

Drug-Associated QTc Prolongation in Geriatric Hospitalized Patients: A Cross-Sectional Study in Internal Medicine

Objective

The primary objectives of this prospective cross-sectional study were to estimate the prevalence of drug-related long QT syndrome (LQTS) and the prevalence of use of QT-prolonging drugs in older patients admitted to an internal medicine unit.

Methods

We screened consecutive patients hospitalized in an internal medicine unit over a 2-year period. A 12-lead electrocardiogram using an electrocardiograph with automated measurement of QT interval was recorded. Patient characteristics (age, sex, body mass index), drug treatments, and variables associated with QT interval prolongation, including hypothyroidism, type 2 diabetes mellitus, and cardiac disease, were also recorded. In addition, we also measured serum levels of potassium, calcium, magnesium, and creatinine at admission. The list of medications known to cause or to contribute to LQTS was obtained from CredibleMeds^®.

Results

A total of 243 patients were enrolled: mean ± standard deviation age, 79.65 ± 8.27 years; males, n = 121 (40.8%); mean corrected QT (QTc) interval, 453.70 ± 43.77 ms. Overall, 89/243 (36.6%) patients had a prolonged QTc interval, with 29/243 (11.9%) having QTc interval prolongation > 500 ms (11.9%). A vast majority were prescribed at least one QT-prolonging drug (218/243 [89.7%]), whereas 74/218 (30.5%) were receiving at least one medication with a known risk of Torsades des Pointes (TdP). Proton pump inhibitors were the second most commonly prescribed class of drugs. After logistic regression, male sex was independently associated with LQTS (odds ratio 2.85; 95% confidence interval 1.56–5.22; p = 0.001).

Conclusions

The prevalence of LQTS with QTc interval > 500 ms in geriatric inpatients was > 10%, and QT-prolonging drugs were frequently used on admission (more than 30% of patients were receiving drugs with a known risk of TdP).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00234-x.

Effect of Hydroxychloroquine and Azithromycin on QT Interval Prolongation and Other Cardiac Arrhythmias in COVID-19 Confirmed Patients

BACKGROUND

Hydroxychloroquine with or without azithromycin was one of the common therapies at the beginning of the COVID-19 pandemic. They can prolong QT interval, cause torsade de pointes, and lead to sudden cardiac death. We aimed to assess QT interval prolongation and its risk factors in patients who received hydroxychloroquine with or without azithromycin.

METHODS

This study was a retrospective cohort study. One hundred seventy-two confirmed COVID-19 patients were included in this study, hospitalized at Babol University of Medical Sciences hospitals between March 5, 2020, and April 3, 2020. Patients were divided into two groups: hydroxychloroquine alone and hydroxychloroquine with azithromycin. Electrocardiograms were used for outcome assessment.

RESULTS

83.1% of patients received hydroxychloroquine plus azithromycin vs. 16.9% of patients who received only hydroxychloroquine. The mean age of patients was 59.2 ± 15.4.The mean of posttreatment QTc interval in the monotherapy group was shorter than the mean of posttreatment QTc interval in the combination therapy group, but it had no significant statistical difference (462.5 ± 43.1 milliseconds vs. 464.3 ± 59.1 milliseconds; p = 0.488). Generally, 22.1% of patients had a prolonged QTc interval after treatment. Male gender, or baseline QTc ≥ 450 milliseconds, or high-risk Tisdale score increased the likelihood of prolonged QTc interval. Due to QTc prolongation, fourteen patients did not continue therapy after four days.

CONCLUSIONS

Hospitalized patients treated by hydroxychloroquine with or without azithromycin had no significant difference in prolongation of QT interval and outcome. The numbers of patients with prolonged QT intervals in this study emphasize careful cardiac monitoring during therapy, especially in high-risk patients.

Top 20 drug - drug interactions, polypharmacy and analysis of the nature of risk factors due to QT interval prolonging drug use in elderly psychiatry outpatients

INTRODUCTION AND OBJECTIVES

Psychotropic medications extend the corrected QT (QTc) period in the ECG. Psychiatric patients exposed to ≥ 1 psychotropic medication (s) represent a group with a marked probability of drug-activated QTc-prolongation. Prolonged QTc interval in elderly patients (age > 60 years) is connected to a greater risk of all-cause and coronary heart disease deaths. We investigated the pattern of utilization of QTc-interval prolonging medications, QT-extending interactions between drugs, and prevalence of QTc-interval prolonging risk factors in elderly patients.

METHODS

This was a cross-sectional, prospective study at the Psychiatry OPD at All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, India from October 1, 2017 to December 31, 2018 employing the pertinent prescriptions.

RESULTS

A total of 208 elderly patients (age 60 years or more) visiting the Psychiatry OPD during the aforementioned study period were investigated. 105 (50.5%) patients were males whereas 103 (49.5%) were females in our study. 147 out of 208 patients (70.7%) were using interacting agents with the capacity to produce TdP. 288 interacting torsadogenic medication pairs were unraveled. As per AzCERT/CredibleMeds Classification, 254 (48.8%), 181 (34.8%), and 62 (12%) interacting medications were identified with known, possible, and conditional risk of TdP, respectively. The common interacting medications belonged to antidepressant (144), proton pump inhibitor (91), antipsychotic (85), anti-nausea (46), antimicrobial (39), and H₂ receptor antagonist (15) therapeutic categories.

CONCLUSIONS

Many geriatric patients were administered drugs and drug combinations with heightened proclivity towards QT-interval prolongation. Therefore, we need to exigently embrace precautionary safety interventions, to be vigilant, and forestall QT-prolongation and TdP in clinical settings. Online evidence-based drug information resources can aid clinicians in choosing drugs for psychiatric patients.

Impact of a clinical decision support tool targeting QT-prolonging medications

PURPOSE

To evaluate the impact of a newly implemented clinical decision support (CDS) tool targeting QT interval-prolonging medications on order verification and provider interventions.

METHODS

A multicenter, retrospective quasi-experimental study was conducted to evaluate provider response to CDS alerts triggered during ordering of QT-prolonging medications for adult patients. The primary outcome was the proportion of orders triggering QTc alerts that were continued without intervention during a specified preimplementation phase (n = 49) and during a postimplementation phase (n = 100). Patient risk factors for QTc prolongation, provider alert response, and interventions to reduce the risk of QTc-associated adverse events were evaluated.

RESULTS

The rate of order continuation without intervention was 82% in the preimplementation phase and 37% in the postimplementation phase, representing an 55% reduction in continued verified orders following implementation of the QT-focused CDS tool. Most alerts were initially responded to by the prescriber, with pharmacist intervention needed in only 33% of cases. There were no significant differences in patient QTc-related risk factors between the 2 study groups (P = 0.11); the postimplementation group had a higher proportion of patients using at least 2 QTc-prolonging medications (48%, compared to 26% in the preimplementation group; P = 0.02).

CONCLUSION

Implementation of the CDS tool was associated with a reduction in the proportion of orders continued without intervention in patients at high risk for QTc-related adverse events.

The relationship between atypical antipsychotics drugs, QT interval prolongation, and torsades de pointes: implications for clinical use

Introduction: Increased mortality has been observed in patients with mental health disorders. Specifically, exposure to antipsychotic medications conveys a greater than 2 fold risk of sudden death, thought to be mediated through effects on QT prolongation and risk of torsades de pointes.Areas covered: We review the association between antipsychotic drugs and sudden cardiac death, the physiologic basis for these associations, assessment of patients at risk, and strategies to minimize risk of sudden cardiac death.Expert opinion: Despite the prevalence of antipsychotic medication use for many decades, there remain considerable challenges in reducing the associated risk of sudden cardiac death. A structured algorithm that incorporates patient clinical factors and antipsychotic drug factors may improve risk assessment and reduce the risk of adverse cardiac events. Future advancements in genetics and artificial intelligence may allow for enhanced risk stratification and predicting response (efficacy and adverse effects) to therapy.

Association of atypical antipsychotics and mortality for patients hospitalised with pneumonia

Introduction

Atypical antipsychotics are commonly used in patients with psychiatric conditions and dementia. They are also frequently used in patients being admitted with pneumonia; however, there are few safety data. The purpose of this study was to examine whether atypical antipsychotic use prior to admission is associated with increased mortality in patients with pneumonia.

Methods

We conducted a retrospective cohort study of hospitalised patients with pneumonia over a 10-year period. We included patients 65 years or older and hospitalised with pneumonia. For our primary analysis, we used propensity score matching to balance confounders between atypical antipsychotic users and nonusers.

Results

There were 102 897 patients and 5977 were taking atypical antipsychotics. After matching there were 5513 users and 5513 nonusers. Atypical antipsychotic use was associated with increased odds of 30-day (OR 1.20, 95% CI 1.11–1.31) and 90-day mortality (1.19, 1.09–1.30).

Conclusion

In patients 65 years or older that are hospitalised with pneumonia, we found an association between atypical antipsychotic use and increased odds of mortality. This was particularly pronounced for patients with pre-existing psychiatric or cardiac conditions. We suggest closely monitoring patients who use these medications and minimising their use in older adult patients.

When hospitalised with pneumonia, older patients who use atypical antipsychotics should be monitored closely and their use of these drugs should be minimised as much as possiblehttp://bit.ly/2JEevHV

Frequency, characteristics and nature of risk factors associated with use of QT interval prolonging medications and related drug-drug interactions in a cohort of psychiatry patients

Quite a number of antipsychotic and antidepressant drugs are known to cause significant QT-prolongation. Psychiatric patients constitute a population at notable risk of drug-induced QT-prolongation. The aims were to explore frequency of use of QTc-interval prolonging agents and QT-prolonging drug-drug interactions, and prevalence of risk factors for QTc-interval prolongation in patients reporting to psychiatry out-patient department (OPD) in a tertiary care hospital in India. This prospective cross-sectional study was carried out in the psychiatry OPD at All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, India from October 1, 2017 to September 30, 2018 using the relevant prescriptions (i.e., the OPD case record forms and treatment sheets). For each patient, the entire medication list was analyzed for the possibility of interactions, with particular attention on the high-risk QT prolonging ones. Arizona Center for Education and Research on Therapeutics (AZCERT) QT drug lists were used to classify TdP risks of psychotropic and other medications. One thousand three hundred twenty-six (1326) patients attending the psychiatry OPD during the study period were scrutinized. Seven hundred fifty-one 751 patients (56.6%) were males whereas 575 (43.4%) were females in our study. Of the 1326 patients, 636 patients (47.9%) were identified as receiving interacting medications with the ability to induce torsades de pointe (TdP). Nine hundred seventeen (917) interacting medication pairs with torsadogenic risk were encountered. The most frequently interacting medications were from antipsychotic (794), antidepressant (519), antimicrobial (84), proton pump inhibitor (80), anticonvulsant (66), and anti-nausea (25) therapeutic categories. As per AZCERT classification (CredibleMeds TdP risk-stratification lists), 597 (36.8%), 443 (27.3%) and 432 (26.7%) of the interacting medications were associated with known, possible, and conditional risk of TdP, respectively. Concurrent prescriptions of QT-prolonging drugs is frequent in psychiatry OPD setting. Appropriate precautions should be instituted to obviate undesirable outcomes arising out of these interactions. This highlights the pressing need for clear protocols & strategies for implementation to motivate careproviders with clarity in the context of drug use guidelines for rational and safe prescribing in psychiatry.

QT Assessment in Early Drug Development: The Long and the Short of It

The QT interval occupies a pivotal role in drug development as a surface biomarker of ventricular repolarization. The electrophysiologic substrate for QT prolongation coupled with reports of non-cardiac drugs producing lethal arrhythmias captured worldwide attention from government regulators eventuating in a series of guidance documents that require virtually all new chemical compounds to undergo rigorous preclinical and clinical testing to profile their QT liability. While prolongation or shortening of the QT interval may herald the appearance of serious cardiac arrhythmias, the positive predictive value of an abnormal QT measurement for these arrhythmias is modest, especially in the absence of confounding clinical features or a congenital predisposition that increases the risk of syncope and sudden death. Consequently, there has been a paradigm shift to assess a compound's cardiac risk of arrhythmias centered on a mechanistic approach to arrhythmogenesis rather than focusing solely on the QT interval. This entails both robust preclinical and clinical assays along with the emergence of concentration QT modeling as a primary analysis tool to determine whether delayed ventricular repolarization is present. The purpose of this review is to provide a comprehensive understanding of the QT interval and highlight its central role in early drug development.

Use of azilsartan medoxomil in the primary-care setting in Germany: A real-world evidence study

Objective: To evaluate azilsartan medoxomil (AZM) (Edarbi^®) utilization patterns in the primary-care setting in Germany. Materials and methods: This is a retrospective cohort study among patients receiving AZM in the primary-care setting in Germany. Prescription patterns – including patient demographics, off-label use, use in specific populations, concomitant use of other antihypertensive drugs, and drugs potentially causing interactions with AZM – were analyzed in two periods (01/2012 – 12/2013 and 01/2014 – 11/2016) using the primary-care physician panel of German IMS^® Disease Analyzer, a patient-level electronic medical records database. Results: In total, 852 of 1,159 (74%) and 696 of 811 (86%) patients met the inclusion criteria for both periods, respectively. Approximately 25% of patients were aged ≥ 75 years; 1 patient was < 18 years old; ~ 50% were females. AZM was prescribed for the approved indication of essential hypertension in 83% and 68% of patients in the first and second period, while indication was missing in 12% and 26% of patients, respectively. AZM was coprescribed on the same day with other antihypertensive drugs in 23% (first period) and 37% (second period) of patients. Drugs that might cause an interaction with AZM were coprescribed on the same day in 3% of patients in both periods; overlapping prescription periods were detected in 14% (first period) and 8% (second period) of patients. Coprescription of AZM with angiotensin-converting enzyme (ACE) inhibitors (2%) or aliskiren (< 1%) on the same day was rare in both periods. Overlapping prescription periods with AZM decreased from 20 to 6% for ACE inhibitors and from 8 to 1% for aliskiren. Conclusion: Findings from this real-world evidence study demonstrate that AZM was generally utilized for approved indication and in accordance with the summary of product characteristics recommendations.

Assessment of the risk of QT-interval prolongation associated with potential drug-drug interactions in patients admitted to Intensive Care Units

Objectives

To evaluate the relationship between drug interactions and QT-interval prolongation in patients admitted to a general intensive care unit (ICU).

Methods

This study was approved by the Institutional Review Board and written informed consent was obtained from all patients. From May 2015 to July 2016, all patients over 18 years-old admitted to the ICU for more than 24 h and in whom the QT-interval on the ECG could be read were prospectively included in this observational, cross-sectional study. All medications administered in the 24 h prior to admission were recorded and the QT-interval was measured upon ICU admission and corrected with Bazzet’s formula (QTc). Drug-drug interactions involving drugs potentially associated with QTc prolongation (DDIQT) were searched and QTc increase associated with pharmacokinetic (PK-DDIQT) and pharmacodynamic (PD-DDIQT) interactions was assessed with multiple regression adjusted by patient varibles.

Results

The study population consisted of 283 patients, 54.4% males, mean age 57.6 ± 16.7 years-old. Forty five (15.9%) patients presented 65 DDIQT with predominance of pharmacodynamic (66.1%). The risk of DDIQT prescription increased with lower systolic blood pressure, in hypokalemia, in non-diabetics and with the number of medications. PK-DDIQT alone did not affect the QTc interval (7.75 ms, 95%CI: –22.4 to 37.9 ms, p = 0.61), but PD-DDIQT increased QTc by 28.4 ms (95%CI: 9.67 to 47.4 ms, p = 0.003). Most PD-DDIQT involved metoclopramide with ondansetron or amiodarone, and ondansetron with ciprofloxacin.

Conclusions

In patients exposed to drugs associated with prolonged QTc in the 24 h prior to ICU admission, pharmacodynamic DDIQT are associated with increased risk of QTc prolongation.

The impact of risk minimization measures on compliance and prescribing practices of flupirtine in Germany

Objective: In response to safety concerns, risk minimization measures (RMM) for flupirtine were implemented in Europe in 2013 to reduce hepatotoxicity risk. This study aims to characterize compliance and prescribing practices of flupirtine before and after RMM implementation.Research design and methods: A retrospective pre-post design cohort study was conducted in the outpatient setting using a longitudinal electronic medical record database in Germany. The study population included patients who initiated flupirtine. One-year pre- and post-implementation periods were assessed.Main outcome measures: Six RMM elements were evaluated, including indication of acute pain, use for maximum of 2 weeks, use when other analgesics are contraindicated, no pre-existing liver disease or alcohol abuse, no concomitant drug induced liver injury, and weekly liver function tests.Results: The number of flupirtine users decreased by 34.4% from 18,291 in the pre-implementation period (2012) to 12,000 in the post-implementation period (April 2015 to March 2016). Elements of RMM with substantial improvement included flupirtine prescription duration, where the proportion of patients with duration ≤14 days increased significantly by 16.5% from 74.8% to 91.3% in the pre- and post-implementation periods, respectively. RMM with a moderate-to-high degree of compliance during the post-implementation period, although with a very small or no change from the pre- implementation period, included restriction of flupirtine prescribing to patients with acute pain when other analgesics are contraindicated, and avoiding use in patients with either pre-existing liver disease or concomitant drugs known to have a potential hepatotoxic effect. Weekly liver function tests had a low degree of compliance.Conclusions: These findings demonstrate that, while physicians restricted flupirtine prescriptions to short-term use in the target population of acute pain, not all drug labeling elements were followed to the same extent in routine practice.

Prevalence of Torsades de Pointes inducing drugs usage among elderly outpatients in North Jordan Hospitals

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Demonstrating the urgent need for increasing awareness of TdP's risk induced by chronically used medications.

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The importance of establishing an extensive pharmaceutical care for geriatric population with the aim of improving health outcomes and quality of life in elderly patients.

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To identify the major risk factors associated with increasing the incidence of TdP’s among geriatric patients in Jordan.

Background

Torsade de Pointes (TdP) is an abnormal cardiac rhythm associated with a prolongation of QT interval. Although in most cases it spontaneously returns to the normal rhythm, TdP can lead to sudden cardiac death. Medications are the main cause of QT-prolongation and subsequent TdP flare, even though the exact mechanism of why some people evoke TdP but others do not is still unknown. It is evident that elderly patients are more susceptible to experience drug's side effects especially with chronically used medications.

Objectives

To describe the pattern of prescribing drugs with risk of Torsade’s de Pointes among elderly patients who were visiting different outpatient clinics in North Jordan Hospitals.

Methods

All patients who were aged ≥65 years old and were visiting outpatient clinics in King Abdullah University Hospital (KAUH) and Princess Basma Hospital (PBH) through December 2016 were included in the study. A total of 5319 patients’ dispending records were collected and analyzed for the prevalence of drug-induced TdP using both Microsoft Excel and the SPSS statistical software.

Results

A total of 5319 patients were included in the study, more than half (58.5%, n = 3114) of patients were consuming drugs with risk of TdP. Almost half (49.4%, n = 1539) of these patients were women. The majority of patients (62.3%, n = 1939) were using only one drug with TdP risk. However, other patients were found to take five or six different TdP-inducing drugs. Excluding age and gender, 94.3% (n = 2937) of patients who were using TdP-inducing drugs had at least one additional risk factor of inducing TdP.

Conclusion

High usage of TdP-inducing drugs among geriatric patients in North Jordan demonstrated the urgent need for increasing awareness of TdP’s risk induced by commonly prescribed medications.

High prevalence of the risk factors for QT interval prolongation and associated drug-drug interactions in coronary care units

OBJECTIVES

Patients admitted in coronary care units are susceptible to QT interval prolongation due to numerous risk factors. The purpose of this study was to identify the prevalence of risk factors for QT interval prolongation; QT prolonging medications; drug-drug interactions; their predictors; and torsades de pointes risks of drugs.

METHODS

After obtaining approval, this cross-sectional study was carried out during one-year period in coronary care units of two major tertiary care hospitals of Khyber Pakhtunkhwa, Pakistan. The Arizona Center for Education and Research on Therapeutics QT drugs lists and Micromedex DrugReax® were used to identify the QT prolonging medications and QT prolonging drug-drug interactions.

RESULTS

Total 649 patients were included in this study. The most frequent QT prolonging risk factors included use of ≥ 1 QT prolonging drugs (74.9%) and myocardial infarction (61.3%). Total 181 patients were presented with 361 QT prolonging drug-drug interactions. There was significant association of the occurrence of QT prolonging drug-drug interactions with female gender (p = 0.01), 9-10 prescribed medications (p = 0.001), and > 10 prescribed medications (p < 0.001).

CONCLUSIONS

The majority of patients presented with multiple risk factors for QT prolongation in coronary care units which may precipitate lethal outcomes.

Mechanisms Underlying the Actions of Antidepressant and Antipsychotic Drugs That Cause Sudden Cardiac Arrest

A number of antipsychotic and antidepressant drugs are known to increase the risk of ventricular arrhythmias and sudden cardiac death. Based largely on a concern over the development of life-threatening arrhythmias, a number of antipsychotic drugs have been temporarily or permanently withdrawn from the market or their use restricted. While many antidepressants and antipsychotics have been linked to QT prolongation and the development of torsade de pointes arrhythmias, some have been associated with a Brugada syndrome phenotype and the development of polymorphic ventricular arrhythmias. This article examines the arrhythmic liability of antipsychotic and antidepressant drugs capable of inducing long QT and/or Brugada syndrome phenotypes. The goal of this article is to provide an update on the ionic and cellular mechanisms thought to be involved in, and the genetic and environmental factors that predispose to, the development of cardiac arrhythmias and sudden cardiac death among patients taking antidepressant and antipsychotic drugs that are in clinical use.

Clinical Trials in a Dish: A Perspective on the Coming Revolution in Drug Development

The pharmaceutical industry is facing unprecedented challenges as the cost of developing new drugs has reached unsustainable levels, fueled in large parts by a high attrition rate in clinical development. Strategies to bridge studies between preclinical testing and clinical trials are needed to reduce the knowledge gap and allow earlier decisions to be made on the continuation or discontinuation of further development of drugs. The discovery and development of human induced pluripotent stem cells (hiPSCs) have opened up new avenues that support the concept of screening for cell-based safety and toxicity at the level of a population. This approach, termed “Clinical Trials in a Dish” (CTiD), allows testing medical therapies for safety or efficacy on cells collected from a representative sample of human patients, before moving into actual clinical trials. It can be applied to the development of drugs for specific populations, and it allows predicting not only the magnitude of effects but also the incidence of patients in a population who will benefit or be harmed by these drugs. This, in turn, can lead to the selection of safer drugs to move into clinical development, resulting in a reduction in attrition. The current article offers a perspective of this new model for “humanized” preclinical drug development.

Adverse Drug Event Causality Analysis (ADECA): A Process for Evaluating Evidence and Assigning Drugs to Risk Categories for Sudden Death

Growing evidence indicates that many drugs have the ability to cause a potentially lethal cardiac arrhythmia, torsades de pointes (TdP). This necessitates the development of a compilation of drugs that have this potential toxicity. Such a list is helpful in identifying the etiology of TdP in patients taking multiple drugs and assists decision making by those caring for patients at high risk of TdP. The Arizona Center for Education and Research on Therapeutics (AZCERT) has developed a process to standardize the identification of drugs and place them in risk categories for their clinical ability to cause TdP and QT prolongation. AZCERT's Adverse Drug Event Causality Analysis (ADECA) utilizes 16 types of data drawn from four sources to compile an open-source knowledge base, QTdrugs, which is maintained on the CredibleMeds.org website. Because the evidence for most drugs is incomplete, the ADECA process is used to place drugs into one of three categories that represent different levels of certainty: known TdP risk, possible TdP risk, and conditional TdP risk. Each category has strict evidentiary requirements for clinical evidence of TdP and/or QT prolongation. These are described in this paper. Because evidence can evolve over time, the ADECA process includes the continuous gathering and analysis of newly emerging evidence to revise the lists. The QTdrugs lists have proven to be a valued, readily available, commercial influence-free resource for healthcare providers, patients, researchers, and authors of consensus guidelines for the safe use of medicines.

Potential drug-drug interactions and polypharmacy in institutionalized elderly patients in a public hospital in Brazil

WHAT IS KNOWN ON THE SUBJECT?: Older individuals constitute an increasing proportion of the population, and therefore, are the major consumers of drugs. The elderly, especially those with mental disabilities, frequently develop chronic diseases and start using numerous drugs. Drug-drug interactions (DDIs) are a major clinical problem in the elderly population, and previous studies have focused only on antidepressants and others types of drugs used to treat mental health conditions. WHAT THIS ARTICLE ADDS TO EXISTING KNOWLEDGE?: This study shows that in hospitalized elderly patients with mental disorders (aged 60-69 years), polypharmacy (≥5 drugs) and the use of drugs that act on the cardiovascular, respiratory and nervous systems can lead to potential drug-drug interactions. Moreover, it was reported that the prevalence of drug-drug interactions in elderly patients with mental disorders was high during their hospitalization in a public hospital in Brazil. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Nurses should know the factors associated with drug-drug interactions in hospitalized elderly patients with mental disorders to choose appropriate strategies for avoiding treatment failure and adverse events in patients.

ABSTRACT

Introduction Despite the impact on patient safety and the fact that prevalence is higher in older patients, previous research did not analyse drug-drug interactions (DDIs) in view of nursing care of elderly psychiatric patients. Aim To identify potential drug-drug interactions and polypharmacy in prescriptions of aged inpatients with psychiatric disorders and analyse associated factors. Methods In this retrospective cross-sectional study, we analysed the medical records of institutionalized patients diagnosed with psychiatric disorders (n = 94), aged >60 years, and prescribed multiple medications. Drug prescriptions were checked at admission, midway through and the last prescription. Factors associated with DDI occurrence were assessed using multivariable logistic regression analysis. Results A DDI prevalence potential of 67.0%, 74.5% and 80.8% occurred in patients at admission, midway through hospitalization and the last prescription, respectively. Most of the prescribed drugs were nervous system agents. A high percentage of serious and contraindicated potential DDIs occurred. Age between 60 and 69 years, use of cardiovascular and respiratory system drugs, and the number of medications contributed significantly to DDI. Implications for mental health nursing Knowledge on the factors associated with DDIs in patients with mental disorders can contribute to the improvement of effectiveness and safety of nursing care.

Contribution of medications and risk factors to QTc interval lengthening in the atherosclerosis risk in communities (ARIC) study

RATIONALE, AIMS, AND OBJECTIVES

Prolongation of the corrected QT (QTc) interval is associated with increased morbidity and mortality. The association between QTc interval-prolonging medications (QTPMs) and risk factors with magnitude of QTc interval lengthening is unknown. We examined the contribution of risk factors alone and in combination with QTPMs to QTc interval lengthening.

METHOD

The Atherosclerosis Risk in Communities study assessed 15 792 participants with a resting, standard 12-lead electrocardiogram and ≥1 measure of QTc interval over 4 examinations at 3-year intervals (1987-1998). From 54 638 person-visits, we excluded participants with QRS ≥ 120 milliseconds (n = 2333 person-visits). We corrected the QT interval using the Bazett and Framingham formulas. We examined QTc lengthening using linear regression for 36 602 person-visit observations for 14 160 cohort members controlling for age ≥ 65 years, female sex, left ventricular hypertrophy, QTc > 500 milliseconds at the prior visit, and CredibleMeds categorized QTPMs (Known, Possible, or Conditional risk). We corrected standard errors for repeat observations per person.

RESULTS

Eighty percent of person-visits had at least one risk factor for QTc lengthening. Use of QTPMs increased over the 4 visits from 8% to 17%. Among persons not using QTPMs, history of prolonged QTc interval and female sex were associated with the greatest QTc lengthening, 39 and 12 milliseconds, respectively. In the absence of risk factors, Known QTPMs and ≥2 QTPMs were associated with modest but greater QTc lengthening than Possible or Conditional QTPMs. In the presence of risk factors, ≥2 QTPM further increased QTc lengthening. In combination with risk factors, the association of all QTPM categories with QTc lengthening was greater than QTPMs alone.

CONCLUSION

Risk factors, particularly female sex and history of prolonged QTc interval, have stronger associations with QTc interval lengthening than any QTPM category alone. All QTPM categories augmented QTc interval lengthening associated with risk factors.

Combinations of QTc-prolonging drugs: towards disentangling pharmacokinetic and pharmacodynamic effects in their potentially additive nature

BACKGROUND

Whether arrhythmia risks will increase if drugs with electrocardiographic (ECG) QT-prolonging properties are combined is generally supposed but not well studied. Based on available evidence, the Arizona Center for Education and Research on Therapeutics (AZCERT) classification defines the risk of QT prolongation for exposure to single drugs. We aimed to investigate how combining AZCERT drug categories impacts QT duration and how relative drug exposure affects the extent of pharmacodynamic drug-drug interactions.

METHODS

In a cohort of 2558 psychiatric inpatients and outpatients, we modeled whether AZCERT class and number of coprescribed QT-prolonging drugs correlates with observed rate-corrected QT duration (QTc) while also considering age, sex, inpatient status, and other QTc-prolonging risk factors. We concurrently considered administered drug doses and pharmacokinetic interactions modulating drug clearance to calculate individual weights of relative exposure with AZCERT drugs. Because QTc duration is concentration-dependent, we estimated individual drug exposure with these drugs and included this information as weights in weighted regression analyses.

RESULTS

Drugs attributing a 'known' risk for clinical consequences were associated with the largest QTc prolongations. However, the presence of at least two versus one QTc-prolonging drug yielded nonsignificant prolongations [exposure-weighted parameter estimates with 95% confidence intervals for 'known' risk drugs + 0.93 ms (-8.88;10.75)]. Estimates for the 'conditional' risk class increased upon refinement with relative drug exposure and co-administration of a 'known' risk drug as a further risk factor.

CONCLUSIONS

These observations indicate that indiscriminate combinations of QTc-prolonging drugs do not necessarily result in additive QTc prolongation and suggest that QT prolongation caused by drug combinations strongly depends on the nature of the combination partners and individual drug exposure. Concurrently, it stresses the value of the AZCERT classification also for the risk prediction of combination therapies with QT-prolonging drugs.

Prevalence of QT interval prolonging drug-drug interactions (QT-DDIs) in psychiatry wards of tertiary care hospitals in Pakistan: a multicenter cross-sectional study

Background QT prolongation and associated arrhythmias, torsades de pointes (TdP), are considerable negative outcomes of many antipsychotic and antidepressant agents frequently used by psychiatric patients. Objective To identify the prevalence, levels, and predictors of QT prolonging drug-drug interactions (QT-DDIs), and AZCERT (Arizona Center for Education and Research on Therapeutics) classification of drugs involved in QT-DDIs. Setting Psychiatry wards of three major tertiary care hospitals of Khyber-Pakhtunkhwa, Pakistan. Method This was a multicenter cross-sectional study. Micromedex DrugReax was used for identification of QT-DDIs. TdP risks were identified by the AZCERT classification. Multivariate logistic regression analysis was performed to identify predictors of QT-DDIs. Main outcome measure Prevalence of QT-DDIs (overall, age-wise and gender-wise) and their levels of severity and documentation; AZCERT classes of drugs involved in QT-DDIs; and odds ratios for predictors of QT-DDIs. Results Of 600 patients, 58.5% were female. Median age was 25 years (IQR = 20-35). Overall 51.7% patients had QT-DDIs. Of total 698 identified QT-DDIs, most were of major-severity (98.4%) and fair-documentation (93.7%). According to the AZCERT classification, 36.4% of the interacting drugs were included in list-1 (known risk of TdP), 26.9% in list-2 (possible risk of TdP) and 27.5% in list-3 (conditional risk of TdP). Drugs commonly involved in QT-DDI were olanzapine (n = 146), haloperidol (138), escitalopram (122), risperidone (91), zuclopenthixol (87), quetiapine (n80) and fluoxetine (74). In multivariate logistic regression analysis, QT-DDIs were significantly associated with 6-7 prescribed medications (p = 0.04) and >7 medications (p = 0.03). Similarly, there was significant association of occurrence of QT-DDIs with 2-3 QT drugs (p < 0.001) and >3 QT drugs (p < 0.001). Conclusion A considerable number of patients are exposed to QT-DDIs in psychiatry. There is a need to implement protocol for monitoring the outcomes of QT-DDIs.

Time-to-Onset Analysis of Drug-Induced Long QT Syndrome Based on a Spontaneous Reporting System for Adverse Drug Events

Long QT syndrome (LQTS) is a disorder of the heart’s electrical activity that infrequently causes severe ventricular arrhythmias such as a type of ventricular tachycardia called torsade de pointes (TdP) and ventricular fibrillation, which can be fatal. There have been no previous reports on the time-to-onset for LQTS based on data from spontaneous reporting systems. The aim of this study was to assess the time-to-onset of LQTS according to drug treatment. We analyzed the association between 113 drugs in 37 therapeutic categories and LQTS including TdP using data obtained from the Japanese Adverse Drug Event Report database. For signal detection, we used the reporting odds ratio (ROR). Furthermore, we analyzed the time-to-onset data and assessed the hazard type using the Weibull shape parameter. The RORs (95% confidence interval) for bepridil, amiodarone, pilsicainide, nilotinib, disopyramide, arsenic trioxide, clarithromycin, cibenzoline, donepezil, famotidine, sulpiride, and nifekalant were 174.4 (148.6–204.6), 17.3 (14.7–20.4), 52.0 (43.4–62.4), 13.9 (11.5–16.7), 69.3 (55.3–86.8), 54.2 (43.2–68.0), 4.7 (3.8–5.8), 19.9 (15.9–25.0), 8.1 (6.5–10.1), 3.2 (2.5–4.1), 7.1 (5.5–9.2), and 254.8 (168.5–385.4), respectively. The medians and quartiles of time-to-onset for aprindine (oral) and bepridil were 20.0 (11.0–35.8) and 18.0 (6.0–43.0) days, respectively. The lower 95% confidence interval of the shape parameter β of bepridil was over 1 and the hazard was considered to increase over time.Our study indicated that the pattern of LQTS onset might differ among drugs. Based on these results, careful long-term observation is recommended, especially for specific drugs such as bepridil and aprindine. This information may be useful for the prevention of sudden death following LQTS and for efficient therapeutic planning.

High prevalence of risk factors in elderly patients using drugs associated with acquired torsades de pointes chronically in Colombia

AIMS

Medication is one of the main causes of long QT syndrome (LQTS) and torsades de pointes (TdP), and the older adult population is at particularly high risk. The aim of the present study was to describe the prescription patterns of drugs with a risk of TdP in the Colombian older adult population.

METHODS

Patients older than 65 years who received medication with a risk of TdP during three consecutive months were selected. The medication was obtained and classified according to the QT Drug List from Crediblemeds.org. The data were analysed using SPSS-22.

RESULTS

A total of 55 932 patients were chronically receiving QT-prolonging drugs; 61.9% (n = 34 ,632) were women and the mean age of the sample was 75.6 years. Drugs with a conditional risk were consumed by 95.2% of patients, 5.3% received drugs with a known risk and 2.9% received drugs with a possible risk. Two or more QT-prolonging drugs were consumed by 10.3% of the patients (n = 5786). Most of the sample (96.8%, n = 54 170) had at least one additional risk factor for LQTS, with a mean of 3.1 ± 0.9 risk factors. Patients receiving QT-prolonging drugs for psychiatric and neurological disease were at a higher risk of major polypharmacy [odds ratio (OR) 3.0; 95% confidence interval (CI) 2.80, 3.22) and of receiving high doses of QT-prolonging drugs (OR 3.8; 95% CI 3.52, 4.05).

CONCLUSIONS

The widespread use of medication that causes TdP and the high prevalence of additional risks in the older adult population raise the need for accurate prediction of risk and constant patient monitoring. Patients taking psychiatric drugs are at a higher risk of TdP.

Co-Prescription of QT-Interval Prolonging Drugs: An Analysis in a Large Cohort of Geriatric Patients

BACKGROUND

Drug-induced QT-interval prolongation is associated with occurrence of potentially fatal Torsades de Pointes arrhythmias (TdP). So far, data regarding the overall burden of QT-interval prolonging drugs (QT-drugs) in geriatric patients are limited.

OBJECTIVE

This study was performed to assess the individual burden of QT-interval prolonging drugs (QT-drugs) in geriatric polymedicated patients and to identify the most frequent and risky combinations of QT-drugs.

METHODS

In the discharge medication of geriatric patients between July 2009 and June 2013 from the Geriatrics in Bavaria-Database (GiB-DAT) (co)-prescriptions of QT-drugs were investigated. QT-drugs were classified according to a publicly available reference site (CredibleMeds®) as ALL-QT-drugs (associated with any QT-risk) or High-risk-QT-drugs (corresponding to QT-drugs with known risk of Torsades de Pointes according to CredibleMeds®) and in addition as SmPC-high-risk-QT-drugs (according to the German prescribing information (SmPC) contraindicated co-prescription with other QT-drugs).

RESULTS

Of a cohort of 130,434 geriatric patients (mean age 81 years, 67% women), prescribed a median of 8 drugs, 76,594 patients (58.7%) received at least one ALL-QT-drug. Co-prescriptions of two or more ALL-QT-drugs were observed in 28,768 (22.1%) patients. Particularly risky co-prescriptions of High-risk-QT-drugs or SmPC-high-risk-QT-drugs with at least on further QT-drug occurred in 55.9% (N = 12,633) and 54.2% (N = 12,429) of these patients, respectively. Consideration of SmPCs (SmPC-high-risk-QT-drugs) allowed the identification of an additional 15% (N = 3,999) patients taking a risky combination that was not covered by the commonly used CredibleMeds® classification. Only 20 drug-drug combinations accounted for more than 90% of these potentially most dangerous co-prescriptions.

CONCLUSION

In a geriatric study population co-prescriptions of two and more QT-drugs were common. A considerable proportion of QT-drugs with higher risk only could be detected by using more than one classification-system. Local adaption of international classifications can improve identification of patients at risk.

Drug-induced QT interval prolongation and torsades de pointes: Role of the pharmacist in risk assessment, prevention and management

Torsades de pointes (TdP) is a life-threatening arrhythmia associated with prolongation of the corrected QT (QTc) interval on the electrocardiogram. More than 100 drugs available in Canada, including widely used antibiotics, antidepressants, cardiovascular drugs and many others, may cause QTc interval prolongation and TdP. Risk factors for TdP include QTc interval >500 ms, increase in QTc interval ≥60 ms from the pretreatment value, advanced age, female sex, acute myocardial infarction, heart failure with reduced ejection fraction, hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, treatment with diuretics and elevated plasma concentrations of QTc interval-prolonging drugs due to drug interactions, inadequate dose adjustment of renally eliminated drugs in patients with kidney disease and rapid intravenous administration. Pharmacokinetic drug interactions associated with the highest risk of TdP include antifungal agents, macrolide antibiotics (except azithromycin) and drugs to treat human immunodeficiency virus interacting with amiodarone, disopyramide, dofetilide or pimozide. Other important pharmacokinetic interactions include antidepressants (bupropion, duloxetine, fluoxetine, paroxetine) interacting with flecainide, quinidine or thioridazine. Pharmacists play an important role in minimizing the risk of drug-induced QTc interval prolongation and TdP through knowledge of drugs that are associated with a known or possible risk of TdP, individualized assessment of risk of drug-induced QTc interval prolongation, awareness of drug interactions most likely to result in TdP and attention to dose reduction of renally eliminated QTc interval-prolonging drugs in patients with kidney disease. Treatment of hemodynamically stable TdP consists of discontinuation of the offending drug(s), correction of electrolyte abnormalities and administration of intravenous magnesium sulfate 1 to 2 g.

Drug-drug interactions and QT prolongation as a commonly assessed cardiac effect - comprehensive overview of clinical trials

Background

Proarrhythmia assessment is one of the major concerns for regulatory bodies and pharmaceutical industry. ICH guidelines recommending preclinical tests have been established in attempt to eliminate the risk of drug-induced arrhythmias. However, in the clinic, arrhythmia occurrence is determined not only by the inherent property of a drug to block ion currents and disturb electrophysiological activity of cardiac myocytes, but also by many other factors modifying individual risk of QT prolongation and subsequent proarrhythmia propensity. One of those is drug-drug interactions. Since polypharmacy is a common practice in clinical settings, it can be anticipated that there is a relatively high risk that the patient will receive at least two drugs mutually modifying their proarrhythmic potential and resulting either in triggering the occurrence or mitigating the clinical symptoms. The mechanism can be observed either directly at the pharmacodynamic level by competing for the molecular targets, or indirectly by modifying the physiological parameters, or at the pharmacokinetic level by alteration of the active concentration of the victim drug.

Methods

This publication provides an overview of published clinical studies on pharmacokinetic and/or pharmacodynamic drug-drug interactions in humans and their electrophysiological consequences (QT interval modification). Databases of PubMed and Scopus were searched and combinations of the following keywords were used for Title, Abstract and Keywords fields: interaction, coadministration, combination, DDI and electrocardiographic, QTc interval, ECG. Only human studies were included. Over 4500 publications were retrieved and underwent preliminary assessment to identify papers accordant with the topic of this review. 76 papers reporting results for 96 drug combinations were found and analyzed.

Results

The results show the tremendous variability of drug-drug interaction effects, which makes one aware of complexity of the problem, and suggests the need for assessment of an additional risk factors and careful ECG monitoring before administration of drugs with anticipated QT prolongation.

Conclusions

DDIs can play significant roles in drugs’ cardiac safety, as evidenced by the provided examples. Assessment of the pharmacodynamic effects of the drug interactions is more challenging as compared to the pharmacokinetic due to the significant diversity in the endpoints which should be analyzed specifically for various clinical effects. Nevertheless, PD components of DDIs should be accounted for as PK changes alone do not allow to fully explain the electrophysiological effects in clinic situations.

Electronic supplementary material

The online version of this article (doi:10.1186/s40360-016-0053-1) contains supplementary material, which is available to authorized users.

Prescribers' practice of assessing arrhythmia risk with QT-prolonging medications

AIMS

This study aimed to assess prescribers' monitoring for arrhythmic risk with QT-prolonging medications (LQT drugs).

METHODS

Over a 6-month period, all inpatients under the care of Cardiologists (Cohort A) and General Physicians (Cohort B) at Aberdeen Royal Infirmary who were prescribed drugs with known risk of Torsades de Pointes (TdP) were identified. Admission and repeat electrocardiograms (ECG) after 48 h of commencing a LQT drug were examined. Actions taken if QTc was prolonged and drug-drug interactions were examined. A risk estimate on the UK hospital population was calculated.

RESULTS

Of the 4133 patients admitted during the study period, 234 (6%) patients were prescribed a LQT drug. There were 100 (43%) patients in Cohort A and 134 (57%) patients in Cohort B. Of those admitted with a pre-existing LQT drug prescription, an ECG was performed in 167 (96%) of patients and QTc prolongation was identified in 59 (34%). Of those who received a new prescription of LQT drug, 23 (38%) had QTc prolongation and more patients in Cohort A than Cohort B had a repeat ECG within 48 h (84% vs. 11%, P < 0.0001). QTc prolongation was only recognized in 6 (14%) and 2 (5%) patients in cohorts A and B, respectively. Only one patient at risk of drug interaction had QTc prolongation. None of our patients had documented TdP in hospital. Extrapolating these findings to the UK hospital population, at least 204 and <17-175 patients on cardiac and noncardiac LQT drugs, respectively, might be expected to have TdP each year.

CONCLUSION

Recognition of acquired QTc prolongation is poor. Clinician education and an electronic prescribing system may improve this situation.

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.

Cardiac repolarization abnormalities among patients with various stages of chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) are at increased risk of life-threatening cardiovascular arrhythmias. Although these arrhythmias are usually secondary to structural heart diseases that are commonly associated with CKD, a significant proportion of cases with sudden cardiac death have no obvious structural heart disease. This study aims to explore the relationship of cardiac repolarization in patients with CKD and worsening kidney function.

HYPOTHESIS

There is cardiac repolarization abnormalities among patients with chronic kidney disease.

METHODS

This was a retrospective, chart-review study of admissions or clinic visits to a university hospital between 2005 and 2010 by patients with a diagnosis of CKD. Inclusion criteria selected patients who had 12-lead surface electrocardiography (ECG), renal function tests within 24 hours, and transthoracic echocardiography within 6 months. Cases with a documented etiology for the corrected Qt (Qtc) interval prolongation including structural heart disease, QT prolonging drugs, or relevant disease conditions, were excluded.

RESULTS

Our sample size was 154 ECGs. Two-thirds of patients with CKD had QTc interval prolongation, and about 20% had a QTc interval >500 ms. QTc interval was significantly different and increased with each successive stage of CKD using the Bazett (P < 0.006) or Fridericia (P = 0.03) formula. QTc interval correlated significantly with serum creatinine (P = 0.01). These finding were independent of age, gender, potassium, and calcium concentrations.

CONCLUSIONS

The progression of CKD resulted in a significant delay of cardiac repolarization, independent of other risk factors. This effect may potentially increase the risk of sudden cardiac death, and may also increase the susceptibility of drug-induced arrhythmia.

Determinants of torsades de pointes in older patients with drug-associated long QT syndrome: a case-control study

OBJECTIVE

Many elderly patients are routinely exposed to drugs that may prolong the cardiac QT interval and cause Torsades de pointes (TdP). However, predictors of TdP in patients with drug-associated long QT syndrome (LQTS) are not fully understood, especially in the geriatric population. The objective of this study was to identify risk factors of TdP in elderly patients with drug-associated LQTS.

METHODS

In this retrospective, case-control study, documented reports of drug-associated LQTS plus TdP (n = 125) and LQTS without TdP (n = 81) in patients ≥65 years of age were retrieved from the French Pharmacovigilance Database over a 10-year period. Available clinical, biological, and drug therapy data were compared in the two groups and logistic regression was performed to identify significant predictors of TdP.

RESULTS

The uncorrected QT interval was significantly longer in patients with TdP than in patients without TdP (577 ± 79 vs. 519 ± 68 ms; p = 0.0001). The number of drugs with a known risk of TdP administered to each patient was not a predictor of arrhythmia, nor was female gender. Logistic regression analysis identified the uncorrected QT interval as the only significant predictor of TdP. The receiver operating characteristic curve analysis was characterized by an area under the curve of 0.77 (95 % confidence interval 0.64-0.88) and a QT cutoff of 550 ms.

CONCLUSION

The uncorrected QT interval was significantly associated with the probability of TdP in elderly patients with acquired, drug-associated LQTS.