PS-004 Analysis of the use of psychotropic drugs and pharmacological interactions in spanish chronic psychiatric patients

BackgroundSide effects produced by drugs are an emergent problem in developed countries, with major consequences for health assistance and economy. Polymedication produces important interactions which sometimes have relevant clinical repercussions.PurposeThe aim of this present study was to describe the current use of antipsychotic drugs in chronic patients in a psychiatric hospital and the potential risk of producing drug interactions (DI).Material and methodsThis was a descriptive cross sectional study analysing psychopharmacological therapeutics in patients admitted to a psychiatric hospital of 300 beds. For each patient, we obtained the following data: psychiatric disease, gender and age. Concerning pharmacotherapy, we obtained the following information: total number of drugs and type of oral or depot injection of antipsychotic medicines. Afterwards the major DI were listed using Micromedex Solutions.ResultsAmong 300 hospitalised patients who were studied, the majority were men (62%) with a median age of 49 ± 13 years; median age of women was 56 ± 16 years. The psychiatric diseases most frequently encountered were paranoid schizophrenia (34%) and undifferentiated schizophrenia (10%). 72% of patients were receiving more than 5 different medicines and the most prescribed being psychoactive drugs (62%). 94% of patients took antipsychotics, and among them, 27% as monotherapy. The average number of prescriptions of antipsychotic drugs per patient was 2.15, the most used being the atypical (70%) with olanzapine (20%), quetiapine (17%) and clozapine (13%). For typical antipsychotic drugs, we can highlight the use of levomepronazine (13%) and haloperidol (12%). 32% of patients (n = 95) were treated by depot injection of antipsychotic and the most frequently used were fluphenazine (34%), paliperidone (29%) and risperidone (28%). 68% of patients presented at least one major DI which increased the risk of developing side effects, with an average of 2 interactions per patient. The possible consequences of those DI were mostly increasing risk of a prolonged QT interval (59.4%) and an increasing risk of cardiac-respiratory arrest (8.3%).ConclusionPsychiatric patients receive a high number of medicines which interact, increasing the risk of occurrence of serious side effects. Detection of DI and therapy optimisation would reduce the risks associated with medication.No conflict of interest.