5PSQ-084 Risk of QT interval prolongation in older patients

Background The QT interval prolongation is a rare adverse effect, but its clinical relevance is very serious, being able to trigger sudden cardiac arrest and death. The drugs most frequently involved in QT prolongation are often used among elderly patients. Purpose The objective was to analyse the interventions carried out regarding the prescription of medications in elderly patients who prolong the QT interval. Material and methods This was a transversal descriptive observational study in which the Access registry of the pharmaceutical interventions performed in the Institutionalized Patient Care Unit of the Emergency Department was reviewed. The study period was from January to March 2017. Demographic data of the patients attended (age, sex) were analysed, as well as the number and type of interventions carried out and the drugs involved (no drugs/patient and pharmacological group). Results During the study period, the treatment of 134 patients was reconciled and reviewed, of which 105 required some type of intervention in the usual treatment prescribed. The mean age of these patients was 85.7 years (64.17% females, 35.82% males) with an average of 9.5 drugs per patient. In 18 of the 134 (13.4%) patients, the intervention was related to drugs that prolonged QT, with associations of two or more of these drugs being observed in 83% of the cases. 77.14% of the interventions corresponded with psychotropic drugs (SSRIs, tricyclic antidepressants, duloxetine, antipsychotics, trazodone); 5.71% with antibiotics (azithromycin, levofloxacin), 2.85% with rivastigmine, 2.85% domperidone; 2.85% with antiarrhythmics (amiodarone) and 2.85% with antihistamines H2 (famotidine). In all of them, caution was recommended in the use of these drugs, especially in three of them due to a cardiovascular history. Conclusion Most drugs involved in QT prolongation are psychotropic drugs, very commonly prescribed in this population. In addition, the polypharmacy of the elderly predisposes to the association of drugs whose profile of adverse effects may be enhanced, as is the case of the prolongation of the QT interval. It is important to make prescribers aware of the need for periodic re-evaluation of the risk/benefit of these drugs and avoid, as far as possible, these types of drugs in patients with a cardiovascular history. References and/or acknowledgements https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2909803/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4110870/ No conflict of interest.