Use of analgesic opioids in Portugal – a cross-sectional study
Background: Opioids are important tools in pain treatment, both of cancer and non-cancer origin. Nevertheless, these medicines carry significant risk of misuse, tolerance and dependence, with possible negative outcomes particularly common and potentially more serious among patients concurrently exposed to other psychoactive medicines. The aim of the present study was to characterise opioid use in Portugal.
Methods: Population-based cross-sectional study using data from the National Health Service reimbursement database on all prescribed opioid analgesics (OA) dispensed between 2018 and 2022 in all community pharmacies of Portugal mainland. The study is composed of two phases: the first focuses on global opioid consumption, expressed in number of patients and number of dispensed packages/DDD, and includes demographic, geographic, and prescribing characterisation of the last studied year. The number of DDD/user e DDD/1,000 inhabitants/day were the metrics used to study extent of use in each year. The second phase of the study consists of a detailed analysis of the cohort of patients with at least one package of any OA dispensed in 2019 but with no dispensing in 2018, in order to ensure incident use and first prescription of OA, that were followed until the end of the study period.
Results: Global use analysis has shown that the association tramadol + paracetamol accounts for 46% of total opioid consumption, used by 69.9% of the total number of individual patients dispensed at least one OA during the study period. OA treatment intensity increased from 36.3 DDD/user in 2018, to 45.2 DDD/user in 2022, corresponding to 7.6 and 10.1 DDD/1,000 inhabitants/year, respectively. During the last studied year, strong opioids were responsible for 30.8% of total OA consumption, which except for tapentadol (59.6% prescribed in primary care), were mostly prescribed in the outpatient hospital setting. Geographical analysis has shown that the central region of Portugal leads consumption, with 14.3 DDD/1,000 inhabitants/day (mean of 10.3 DDD/1,000 inhabitants/day at national level) in 2022.
Looking at the 2019 cohort, a total of 439,168 users (4.5% of the population) were OA incident users, of which 63.3% were females. Median age was 68 years (IQR 56-79) and almost half of total OA users were older than 65 years, with consumption per capita showing increasing number of OA users with age. About 89% of the total cohort received always the same OA throughout the study period, 9% used two different OA, and 1% three or more. Analysis is currently ongoing to detail the cohort patterns of use at individual level.
Conclusions: Although OA consumption in Portugal is not high and an important proportion of prescription is performed in the outpatient hospital setting, thereby being expected an adequate monitoring of opioid therapy, the increase in opioid consumption during the last years points to the need of close monitoring, given its associated possible risks.
