Extent of use of QT interval prolonging medication in Psychiatry in Patient in a tertiary care hospital

Psychiatric patients constitute a population at notable risk of drug induced QT-prolongation. Quite a number of antipsychotic and antidepressant drugs are known to cause significant QT-prolongation. The aims were to explore extent of use of QTc-interval prolonging agents in Psychiatry In- Patient in a tertiary care hospital in India. The study was carried out in the psychiatry In- Patient at NEIGRIHMS, Shillong, India . 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.246 patients attending the psychiatry department during the 3 months study period were scrutinized. 149 patients (61%) were males whereas 97 (39%) were females in our study. Of the 246 patients, 207 patients (84%) were identified as receiving interacting medications with the ability to induce torsades de pointe (TdP). 349 (51.8%) interacting medications with torsadogenic risk were encountered out of total 674 medication prescribed to 246 patients. The most frequently interacting medications were from antidepressant (190), antipsychotic (132), antidementia (14), proton pump inhibitor (7) therapeutic categories. As per AZCERT classification (CredibleMeds TdP risk-stratification lists), 110 (31.5%), 46 (13.2%) and 193 (55.3%) 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 setting. Appropriate precautions should be instituted to provide caregivers with clear guidelines on how to use these drugs in a responsible and safe way.