9 Clinical Trials for Various Conditions
Torsades de pointes (TdP) is a polymorphic ventricular tachycardia associated with prolongation of the heart rate-corrected QT (QTc) interval on the electrocardiogram (ECG). TdP can result in catastrophic outcomes, including sudden cardiac death. QTc interval prolongation is a well-known adverse event associated with methadone use. While some risk factors for methadone-associated QTc interval prolongation and TdP have been identified, the contribution of interacting drugs and concomitant administration of other QTc interval-prolonging agents to overall risk has not been determined. The effect of ECG screening and monitoring on clinical outcomes in patients taking methadone has not been evaluated, and clinical opinion regarding routine ECG and risk factor monitoring varies. Twelve lead ECGs are costly and time-intensive for clinic staff. ECG screening in selected patients based on presence of QTc interval risk factors, rather than broadly in all patients taking methadone, would facilitate more targeted, strategic QTc interval monitoring. The FDA-approved AliveCor® handheld smart phone/tablet device records a single lead ECG (iECG) within 30 seconds. Use of this device may facilitate simpler, more rapid and less costly ECG monitoring in patients receiving care in narcotic treatment centers. Our long-term goals are to determine mechanisms by which drugs cause arrhythmias, to identify patients at greatest risk of drug-induced arrhythmias, and to determine safe and effective methods for prevention and management of drug-induced arrhythmias. Specific Aim 1: Identify independent risk factors for methadone-induced QTc interval prolongation in patients undergoing care in a narcotic treatment center. Research Design: This will be a retrospective/prospective analysis of ECGs and health information from patients receiving methadone therapy in the Eskenazi Health Midtown Narcotic Treatment Center in Indianapolis, IN. Currently, at the Midtown Narcotic Treatment Center, baseline 12-lead ECGs are recorded for all patients prior to initiation of methadone therapy; follow-up ECGs are obtained approximately 2 weeks after methadone initiation only in patients with a baseline prolonged QTc interval. At the start of the study, methadone-treated patients who have not had follow-up ECGs on methadone therapy will be identified and contacted prospectively. Those consenting to participation will undergo a follow-up 12-lead ECG to determine QTc interval during methadone maintenance therapy. For all patients, retrospective analysis of the electronic medical record will be performed to document sex, pregnancy status, age, family history, current and past medical history, and concomitant use of prescribed, over the counter, and illicit drug use with the aim to identify all potential risks. QTc interval prolongation will be defined as QTc interval ≥ 500 ms or an increase in QTc interval of ≥ 60 ms compared with the baseline QTc interval. Electronic health information variables will be compared in patients who develop methadone-associated QTc interval prolongation versus those who do not using univariate analysis. Patients with prolonged QTc interval at baseline will be excluded from the study. Specific Aim 2: Validate the handheld AliveCor® smart phone/tablet iECG device as a simple, rapid method of monitoring QTc intervals in methadone-treated patients in a narcotic treatment center. Research Design: A separate cohort of patients will be utilized to validate the AliveCor® device for use in measuring QTc intervals in patients initiated and maintained on methadone in a narcotic treatment center. Twelve lead ECGs and simultaneous single lead ECGs using the AliveCor® device will be recorded for all newly enrolled patients at baseline and again after six weeks of methadone therapy. The QTc identified by the 12-lead ECG will be compared to the single lead ECG for all baseline and follow-up recordings to validate the use of the AliveCor® device for potential use in narcotic treatment centers to reduce cost and save time. Comparison of QTc intervals between the 12-lead and single lead measurements will be performed using the Bland-Altman method for analysis of measurement agreement. The mean and 95% confidence interval of the difference in QTc interval between the two methods will be calculated. This will be a pilot study to justify a larger extramural study to develop and validate a risk score for methadone-induced QTc interval prolongation and to use the handheld ECG device for QTc interval monitoring in patients identified as high-risk using this risk score. Our rationale is that identification of risk factors for methadone-induced QTc interval prolongation and quantification of degree of risk conferred by each risk factor will ultimately reduce the incidence and risk of QTc interval prolongation through targeted ECG monitoring of patients at highest risk and modulation of modifiable risk factors.
Torsades de pointes (TdP) is a potentially fatal ventricular arrhythmia associated with corrected QT (QTc) interval prolongation. More than 50 commonly used drugs available on the US market may cause QTc interval prolongation and TdP. While TdP occurs more commonly in women, 33-45% of all cases of TdP have occurred in men. Older age is a risk factor for drug-induced TdP in men, possibly due to declining serum testosterone concentrations. Available evidence shows an inverse relationship between QTc intervals and serum testosterone concentrations. In addition, experimental data, including those from the investigators' laboratory, suggest that both exogenous testosterone or progesterone administration may be protective against prolongation of ventricular repolarization and TdP. Specific Aim: Establish the influence of transdermal testosterone administration and oral progesterone administration as preventive methods by which to diminish the degree of drug-induced QT interval prolongation in men 65 years of age or older. Hypothesis: Transdermal testosterone administration and oral progesterone administration both effectively attenuate drug-induced QT interval response in older men. To test this hypothesis, transdermal testosterone, oral progesterone or placebo will be administered in a 3-way crossover study to men 65 years of age or older. QTc interval response to low-dose ibutilide will be assessed. The primary endpoints will be Fridericia-corrected QT interval (QTF) response to ibutilide, in the presence and absence of testosterone, and in the presence or absence of progesterone: 1) Effect on pre-ibutilide QTF, 2) Effect on maximum post-ibutilide QTF, 3) Effect on % change in post-ibutilide QTF, and 2) Area under the QTF interval-time curves.
This is a single-arm, open-label, Phase 4 study evaluating the effect of GO on the QTc, pharmacokinetics, safety, and immunogenicity of GO as a single-agent monotherapy in adult and pediatric patients with relapsed or refractory CD33-positive AML.
This is a clinical evaluation of QT/QTc interval prolongation and proarrhythmic potential of GMI-1070 in African-American Adult subjects. This is conducted as part of standard drug development.
This study has been designed in compliance with the ICH-E14 guideline 2005 to evaluate the QT/QTc interval prolongation and proarrhythmic potential for non-antiarrhythmic drugs.
A number of drugs used in the perioperative period may cause prolongation of the QT interval on the electrocardiogram (EKG). These drugs include inhalational agents, antiemetic agents, pain medications, and drugs used to reverse the effects of muscle relaxants. Approximately 80% of patients undergoing a general anesthetic will demonstrate significant prolongation of the QT interval on the EKG in the postanesthesia care unit (PACU) following surgery. The concern with QT interval prolongation is that it can result in a potentially lethal ventricular arrhythmia termed torsade des pointes. Despite the concurrent use of several of these medications in a typical general anesthetic, torsade des pointes is a rare event in the perioperative period. In the past decade, the use of intravenous methadone as part of a balanced anesthetic technique has increased significantly. A single dose provided at induction of anesthesia can provide prolonged (24-48 hours) relief from pain. Studies in patients receiving long-term treatment with methadone for addiction therapy or chronic pain have revealed that these patients are at risk for QT prolongation, torsade des pointe, and cardiac death. However, the effect of a single intravenous dose of methadone used in the operating room on the QT interval is uncertain. The aim of this randomized clinical trial is to compare the impact of methadone, when compared to the more commonly-used opioid hydromorphone, on QT prolongation measured with a 12-lead EKG in the PACU and on postoperative day 1. We hypothesize that methadone will not result in significant QT prolongation when used as part of a standardized general anesthetic.
The purpose of this study is to assess the use of the medication ondansetron (zofran) in the emergency department. There are studies of the ability of ondansetron to cause a prolongation in the QT interval (a certain measurement on an EKG) in anesthesia and cancer patients, but not on emergency department patients. This is an observational study where patients that are going to receive the anti-nausea medicine ondansetron in the emergency department will have an EKG performed every 2 minutes for 20 minutes to determine if the QT interval prolongs and returns to normal in that time period. Any serious outcomes will be reported. There is expected to be no adverse outcomes from this routinely used medication.
This study is primarily to evaluate the single dose pharmacokinetics of CP-751,871 and its effect on QT interval prolongation.
Long QT syndrome (LQTS)is a cardiac disorder that may lead to ventricular arrythmias and culminate in syncope and/or possible death. Recently, researchers have developed a way of discovering patients with LQTS by using low doses of epinephrine by a continuous, intravenous infusion in adults. Epinephrine, or adrenaline, is produced by our bodies in times of stress. By producing adrenaline, your body allows itself to adapt to its stressful environment and take appropriate actions (i.e. fight or flight response). By simulating this response with very small amounts of epinephrine, researchers have shown prolongation of the QT interval does not occur in normal healthy adults. However, adults with confirmed LQTS Type 1 (LQTS-1) will prolong their QT interval when given low dose epinephrine. Therefore, this test can act as a safe means of identifying adults with LQTS-1 who do not have prolonged QT intervals on their resting EKGs. However, LQTS is not just a disease of adults, it affects children as well. Currently the standard of care is to obtain resting EKGs on our pediatric patients which can miss those patients with concealed LQTS. Those patients, who are old enough, can undergo exercise testing. Yet this leaves young children unable to run on a treadmill without a diagnostic test. Hypothesis: The low-dose epinephrine infusion stress test does not cause prolongation of the QT interval in an electrophysiologically normal healthy pediatric population.