Background LQTS, the long QT syndrome, is associated with an increased risk of ventricular arrhythmias, named torsades de pointes (TdP). TdP can result in ventricular fibrillation and sudden death. The incidence of such arrhythmia is often a result of polypharmacy and drug–drug interactions. Several studies have shown an advantage of pharmacist involvement in monitoring and reducing the risk.
Purpose The purpose of this study was to evaluate the potential role of a clinical pharmacist consult on monitoring and management of pharmacodynamic drug–drug interactions potentially causing QTc prolongation.
Material and methods This was an observational and retrospective study. It included all admissions to a single 44 bed internal medicine department during 2013 for whom a ‘combination of drugs’ was prescribed. The ‘combination of drugs’ was defined as pharmacodynamic drug–drug interactions of major severity, potentially causing QTc prolongation. The study group, as opposed to the control group, received a clinical pharmacist consult and interventions. Demographic data and risk factors were collected and ECG records were obtained. Patients’ files were scanned for doctor’s mentioning of ECG results in the follow-up, and treatment interventions. The ECG records were read by an internal medicine resident. Evaluation of the impact of pharmacist consult on doctor’s follow up, and ECG records, was made. Factors affecting a doctor’s decision to intervene were identified.
Results During the study period, pharmacist consultations were written in 643 electronic charts. About 6% of the total consultations involved QT prolonging interactions. Pharmacist consult resulted in higher ECG recordings (71.8% vs 39.2%; p=0.0004). In addition, the consult resulted in higher doctor’s attention to ECG findings in the follow-up (53.8% vs 5.7%; p<0.0001). Finally, a doctor’s decision to intervene in the treatment was influenced by the pharmacist consult (p=0.03). This decision was not influenced by the degree of QTc prolongation or the presence of risk factors. The most frequent intervention was drug discontinuation.
Conclusion A clinical pharmacist has the ability to identify potentially dangerous drug combinations, increase medical awareness and monitoring where necessary. Most importantly, a pharmacist’s consult resulting in a doctor’s attention to ECG findings in the follow-up increases the probability of doctors’ interventions even in the absence of meaningful ECG changes.
No conflict of interest