Multifactorial QT interval prolongation

Acquired long QT interval has been widely reported to be a consequence of drug therapy and electrolyte disturbances. We describe two cases of multifactorial acquired QT interval prolongation and torsades de pointes. In the first case, the drugs venlafaxine, amiodarone and domperidone may have contributed to QT interval prolongation in a patient with hypokalemia and hypomagnesaemia. In the second case, QT interval prolongation occurred in a patient taking quetiapine and citalopram, and whose use of hydrocholorothiazide and history of chronic alcohol abuse likely contributed by rendering the patient hypokalemic. These cases highlight the potential risks associated with polypharmacy and demonstrate that though torsades de pointes is an uncommon arrhythmia, the combination of multiple factors known to prolong QT interval may precipitate this life-threatening arrhythmia. (Cardiol J 2010; 17, 2: 184-188

Case Report Multifactorial QT Interval Prolongation and Takotsubo Cardiomyopathy

A 71-year-old woman collapsed while working as a grocery store cashier. CPR was performed and an AED revealed torsades de pointes (TdP). She was subsequently defibrillated resulting in restoration of sinus rhythm with a QTc interval of 544 msec. Further evaluation revealed a diagnosis of Takotsubo Cardiomyopathy (TCM) contributing to the development of a multifactorial acquired long QT syndrome (LQTS). The case highlights the role of TCM as a cause of LQTS in the setting of multiple risk factors including old age, female gender, hypokalemia, and treatment with QT prolonging medications. It also highlights the multifactorial nature of acquired LQTS and lends support to growing evidence of an association with TCM

Evaluation of the Use of Intravenous Magnesium Replacement Therapy in Adult Medical and Surgical Patients

Pharmacy residents have the opportunity to complete a research project during their residency training, which provides them with skills on how to conduct and manage a research project. Projects often represent an area of interest and need that has been recognized by the host institution’s pharmacy department. Projects are presented as a poster at an annual CSHP Ontario Branch Residency Research Night, and many eventually go on to be published in a peer-reviewed journal.Background: Guidance for appropriate prescribing of magnesium replacement therapy is lacking, as there are no universal evidence-based guidelines for hypomagnesemia treatment outside of the cardiac and critical care settings. A single dose of intravenous (IV) magnesium is often insufficient for treatment. Total repletion of magnesium may take several days of continued supplementation. Serum magnesium levels should ideally be assessed 36 to 48 hours post-infusion. It is recommended that asymptomatic patients be treated with oral magnesium whenever possible. Objective: To evaluate use of IV magnesium replacement therapy in adult medical and surgical patients at Kingston Health Sciences Centre (KHSC). Methods: A prospective, observational, drug use evaluation of IV magnesium for hypomagnesemia treatment was conducted between January and March 2018. Patients prescribed IV magnesium for other indications, as well as those receiving parenteral nutrition were excluded. Results: Sixty doses of IV magnesium were included and for 21 (35%) of these, oral magnesium would have potentially been suitable. There were 42 orders (70%) for 2 g, 17 orders (28.3%) for 4 g, and 1 order (1.7%) for 6 g doses to be administered, respectively. Patients with lower serum magnesium levels were more likely to be prescribed a higher dose. No post-treatment magnesium levels were drawn after 20% of doses. When drawn, post-dose magnesium levels were measured less than 24 hours post-infusion for 87.5% of doses. After a single 4 g dose of IV magnesium and when subsequent serum levels were available, magnesium levels remained below the reference range after at least 36 hours post-infusion. Conclusion: Improvement is needed in the prescribing and monitoring of IV magnesium therapy for hypomagnesemia. The KHSC Hypomagnesemia Treatment Guidelines were revised to recommend higher consecutive dosing based on baseline serum magnesium levels and to repeat levels 36 to 48 hours post-infusion after the last dose given

Evaluation of a Pharmacist-Led Proton Pump Inhibitor Deprescribing Process in an Acute Care Hospital

Pharmacy residents have the opportunity to complete a research project during their residency training, which provides them with skills on how to conduct and manage a research project. Projects often represent an area of interest and need that has been recognized by the host institution’s pharmacy department. Projects are presented as a poster at an annual CSHP Ontario Branch Residency Research Night, and many eventually go on to be published in a peer-reviewed journal.Rationale: The long term use of proton pump inhibitors (PPIs) has been associated with an increased risk of morbidity. The ongoing need for PPIs is often not reassessed in a timely fashion. The transition of care between the community and the hospital may present a suitable opportunity for the review of a patient’s medications, and hospital pharmacists have the potential to instigate the deprescribing process. Objectives: To determine the effectiveness and feasibility of the implementation of a systematic pharmacist-led PPI deprescribing process in an acute care setting. Methods: A prospective before and after study was conducted in patients newly admitted to the Internal Medicine service with a PPI as a part of their home medication regimen. The pre-intervention phase consisted of usual care, followed by the intervention phase where a pharmacist-led PPI deprescribing process was implemented. The PPI deprescribing tool created through the “Deprescribing Guidelines for the Elderly Project” was used to aid in the deprescribing process. Results: There was no statistically significant difference in the percentage of PPIs deprescribed on discharge between the pre-intervention and intervention phases (6.4% vs. 14.3%, p=0.373). In the intervention phase, 21 patients receiving a PPI prior to admission were assessed for appropriateness of deprescribing by the investigator. Deprescribing was appropriate for seven patients, of which six were agreeable to a deprescribing trial. Deprescribing was suggested to the physician by the clinical pharmacist for three patients, all of which were agreed to by the physician. At discharge, one patient’s PPI was deprescribed. The average time used by the investigator to determine the PPI indication and assess for appropriateness was nine minutes. Conclusion: The implementation of a pharmacist-led PPI deprescribing process in an acute care setting did not significantly impact deprescribing rates

Medication Prescribing Errors on a Surgery Service – Addressing the Gap with a Curriculum for Surgery Residents: A Prospective Observational Study

OBJECTIVES Educational interventions with proven effectiveness to reduce medication prescribing errors are currently lacking. Our objective was to implement and assess the effectiveness of a curriculum to reduce medication prescribing errors on a surgery service. METHODS This was a prospective observational cohort study at a Canadian academic hospital without an electronic order entry system. A pharmacist-led medication prescribing curriculum for surgery residents was developed and implemented over 2 days (2 h/day) in July 2019. Thirteen (76%) out of 17 surgery residents contributed pre-implementation data, while 13 (81%) out of 16 surgery residents contributed post-implementation data. Medication prescribing errors were tracked for 12 months pre-implementation and 6 months post-implementation. Errors were classified as prescription writing (PW) or decision making (DM). RESULTS There were a total of 1050 medication prescribing errors made in the pre-implementation period with 615 (59%) PW errors and 435 (41%) DM. There were a mean of 87.5 (SD  =  14.6) total medication prescribing errors per month in the pre-implementation period with 51.3 (11.9) PW and 36.3 (6.0) DM errors. There were a total of 472 medication prescribing errors made in the post-implementation period with 260 (55%) PW and 212 (45%) DM errors. There were a mean of 78.7 (10.3) total medication prescribing errors per month in the post-implementation period with 43.3 (9.5) PW and 35.3 (4.2) DM errors. In the first quarter of the academic year, there were significantly fewer mean total errors per month post-implementation versus pre-implementation (77.7(12.7) versus 107.3(8.1); P   =  .035), with significantly fewer PW errors per month (40.7(13.2) versus 68.7(9.3); P   =  .046) and no difference in DM errors per month (37.0(2.0) versus 38.7(5.7); P   =  .671). There were no differences noted in the second quarter of the academic year. CONCLUSION Medication prescribing errors occurred from PW and DM. Medication prescribing curriculum decreased PW errors; however, a continued education program is warranted as the effect diminished over time

Multifactorial QT Interval Prolongation and Takotsubo Cardiomyopathy

A 71-year-old woman collapsed while working as a grocery store cashier. CPR was performed and an AED revealed torsades de pointes (TdP). She was subsequently defibrillated resulting in restoration of sinus rhythm with a QTc interval of 544 msec. Further evaluation revealed a diagnosis of Takotsubo Cardiomyopathy (TCM) contributing to the development of a multifactorial acquired long QT syndrome (LQTS). The case highlights the role of TCM as a cause of LQTS in the setting of multiple risk factors including old age, female gender, hypokalemia, and treatment with QT prolonging medications. It also highlights the multifactorial nature of acquired LQTS and lends support to growing evidence of an association with TCM