Inappropriate prescription of psychotropic drugs from PEM: tackling challenges of polypharmacy and dependence

David Emanuel Silva Belchior

Key information

Authors:

David Emanuel Silva Belchior (David Emanuel Silva Belchior)

Supervisors:

Rui Miguel Carrasqueiro Henriques (Rui Miguel Carrasqueiro Henriques); Luis António Proença Duarte Madeira

Published in

October 31, 2024

Abstract

The increasing prevalence of mental health disorders has been matched with growing psychotropic drug consumption rates around the world. Assessing psychopharmacoepidemiological and polypharmacy-related trends and their determinants is essential to guide medical care delivery and public health policies. However, studies on the Portuguese case, an example of critically high consumption rates of benzodiazepines and antidepressants, are limited to the pre-COVID-19 pandemic period. Moreover, national studies on polypharmacy are confined to inpatient data. This thesis uses the full (electronic) dispensation registry of antidepressants, benzodiazepines and zolpidem, antipsychotics and mood stabilisers in Portugal during the years of 2019-2022 with the goal of identifying relevant dispensation and polypharmacy patterns prior to, during and after the COVID-19 pandemic. Our findings show a consumption growth trend in antidepressants (7.41% yearly DID, P = 0.0215) which accelerated since 2020, confirmed by the growing number of users (over 15% of the population), overtaking benzodiazepines and zolpidem as the class with most active users. We propose a novel algorithm for identification of time-sensitive polypharmacy events, and assess the underlying polypharmacy patterns between 2020 and 2022 against a simpler, pointwise stance. Considering contentious stances of pointwise psychotropic polypharmacy characterized by regimens with >= 4 drugs (total), >= 3 classes (multi-class), or >= 3 drugs within a given class, we observed in 2022 prevalences of 2.24%, 3.60% and, in the case of antipsychotics, 1.04% of prescriptions, respectively. The prevalence of time-sensitive polypharmacy events was found to be consistently higher in comparison to pointwise polypharmacy, while reflecting homologously similar results.