Introduction: Portugal has one of the highest levels of benzodiazepine's utilization at European level. This issue was highlighted on the latest International Narcotics Control Board report, which advises Portugal to analyse the actual procedures on prescription and utilization of these drugs. This study aimed to analyse Portuguese benzodiazepine's utilization patterns and trends at regional and national level, and analyse its relation with factors known to affect the utilization of these drugs.
Methodology: Drug utilization data refers to the drugs prescribed and dispensed in the ambulatory to the population covered by the National Health Service, from 1st January 1999 to 31st December 2003. Data was expressed in Defined Daily Dose (DDD) per 1000 inhabitants per day (DHD).
Results: In the Portuguese National Health Service during the period in study there was a decrease of 1.2% on benzodiazepine's utilization. Nevertheless, it was observed an increase on anxyolitics benzodiazepine's utilization (3.8%;72.66 DHD), although hypnotics benzodiazepine's suffered a marked decrease (-21.9%;13.15 DHD). The expenditure has not followed the utilization's trend, and in the period in study the retail sale price expenditure increased 12%. Anxyolitic benzodiazepine's utilization accounted for 85% of the growth on expenditure observed in this study. At national level there were some asymmetries either on utilization's level or on drug utilization's pattern. In 2003, Faro, Bragança and Viana do Castelo were the sub-regions with the lowest utilization level and Portalegre and Evora the ones with the highest levels. Lisbon presented the highest decrease either on percentual (-13.8%) or on absolute (-13.45 DHD) values.
Discussion: Benzodiazepine's utilization in Portugal was considered of concern by International Narcotics Control Board. Therefore the stabilization on utilization, with even a small decrease, should be considered potentially positive. The asymmetries either on utilization's level or on drug utilization's pattern do not seem to be totally attributable to age-structure, unemployment levels or the percentage of retired people, as there wasn't a statistical significant relation between these variables. For this reason the variations on Benzodiazepine's utilization in Portugal seem to be attributed to a combination of different factors, which emphasize the need of more initiatives conducted to health care professionals and patients, in order to diminish the chronic use of these drugs.