Changes in the prescribing pattern of antidepressant drugs in elderly patients: an Italian, nationwide, population-based study

Despite the high use of antidepressants (ADs) among the elderly, there is limited information about the prescribing pattern of these drugs in the Italian elderly population. The aim of this study was to analyze the trend in the use of ADs in the Italian elderly patients in the years 2003-2009, and specifically, to evaluate rates and predictors of AD treatment discontinuation in depressed older patients. The nationwide general practice Health Search Database (HSD) was used to identify AD users aged 65 years old and over from 2003 to 2009. ADs were categorized as (1) selective serotonin reuptake inhibitors (SSRIs); (2) serotonin-norepinephrine reuptake inhibitors (SNRIs); (3) tricyclic antidepressants (TCAs); (4) noradrenergic and specific serotonergic antidepressants (NaSSAs); and (5) other ADs. Incidence and prevalence of AD use per 1,000 inhabitants was calculated by drug class and single compound. We also measured rates and predictors of AD discontinuation (i.e., treatment gap ≥ 60 days) during the first year of therapy. Overall, 39,557 AD users ≥65 years (17 % of the total HSD elderly population) were included in the study. SSRIs were increasingly and most frequently prescribed ADs (102.7-195.3 per 1,000 over seven years). The most common indications for AD use were depression and anxiety. Overall, 14 % of AD users continued their AD medication without treatment gaps, 27 % were intermittent AD users and 58 % discontinued their ADs during the first year of follow-up. Specific AD classes such as TCAs and ‘other ADs were found to be predictors of discontinuation. In depressed patients, the use of NaSSas, TCAs and ‘other ADs as well the concomitant use of >5 drugs (other than ADs) and living in Southern Italy were more likely to predict discontinuation. ADs, especially SSRIs, are widely and increasingly prescribed in elderly Italian patients in recent years. The observed high AD discontinuation rates are likely to impact the achievement of a therapeutic endpoint in depressed patients. Patients who are at high risk of AD discontinuation such as those receiving multi-drug therapy or living in Southern Italy should be monitored more closely to improve benefits of AD treatments.