4CPS-137 Review of 3 month prescriptions containing drugs inducing QT prolongation and torsade de pointe

Background and importance In our psychiatric hospital, it is common to prescribe psychotropic medications such as neuroleptics. One side effect of this drug class is to induce QT prolongation. The more torsadogen drugs we prescribe, the more rhythmic cardiac disease, such as torsade de pointe, may occur. Our hospital drug formulary contains three highly torsadogen drugs: escitalopram, hydroxyzine and domperidone. They must be avoided in situations that may increase the risk of torsades de pointes, such as hypokalaemia, bradycardia and other drugs that induce QT prolongation. Aim and objectives To analyse prescriptions containing at least one of three highly torsadogen drugs and detect torsadogen risk situations. Material and methods We retrospectively analysed all prescriptions over 3 months containing at least one of our three highly torsadogen drugs. We also had access to biological results and bradycardia was mentioned in the patient medical file. For each prescription of one of these three drugs, we checked that no other torsadogen drugs was prescribed, and that there was no bradycardia or hypokalaemia. Results During our study period, among all 584 prescriptions, we found 28 containing at least one of our three highly torsadogen drugs, including 8 contraindications (CI) due to co-prescription with other torsadogen drugs: 13 prescriptions containing escitalopram with 2 CI, 10 prescriptions containing hydroxyzine with 2 CI and 5 prescriptions containing domperidone with 4 CI. For each of those 8 contraindications, a pharmacist intervention was redacted to stop the highly torsadogen drug prescription. Seven were accepted and followed and one was partially accepted. Of the total prescriptions, 11% contained drugs that might induce bradycardia and 53% contained drugs that might induce hypokalaemia. However, among 28 prescriptions containing our three highly torsadogen drugs, bradycardia and hypokalaemia were not found. Conclusion and relevance Prescribers may not know enough about the torsadogen risks of escitalopram, hydroxyzine and domperidone, with 80% of these prescriptions containing CI. The pharmacy intervention helped to avoid those 8 CI. This work reminds us to be vigilant about torsadogen drugs, providing many interactions. We regularly inform prescribers about drugs inducing QT prolongation, hypokalaemia or bradycardia to improve prescriptions. References and/or acknowledgements No conflict of interest.