Use and treatment modalities for SSRI and SNRI antidepressants in Italy during the period 2003-2009

Objectives: This drug utilization study aims to evaluate the incidence and prevalence of prescribed antidepressants (SSRIs or SNRIs) and to describe treatment modalities in Italy during the period 2003-2009. Methods: This retrospective analysis on the prescription and treatment modalities of SSRIs or SNRIs is based on an Italian general practice database, which includes data on about 1,000,000 patients. Eligible patients should have age >= 18 years, and >= 1 year of clinical history. Prevalence, incidence of use and adherence were calculated for SSRIs and SNRIs and for the individual agents. Results: The prevalence of SSRI use increased from 7.5% (2003) to 13.1% (2009) while the prevalence of SNRI use increased from 0.8% to 2.5%. The most evident increase was reported for escitalopram (+2.78%). The number of new antidepressant users (incidence rate) showed a modest decrease for SSRIs (-0.3%) and a slight increase for SNRIs (+0.9%). A higher percentage of continuers was reported for SSRIs versus SNRIs (15.1% vs 13.0%). Escitalopram was associated with the highest percentage of continuers and with the highest number of days of uninterrupted treatment. Overall, over 10% of antidepressant users switched their first choice during one year of follow-up. Escitalopram was associated with the highest frequency of 'high' adherers (28.5%). Conclusions: SSRIs may be regarded as the elective treatment for depression. Of the SSRIs, escitalopram seems to be associated with the highest number of days of uninterrupted treatment, the lowest proportion of switchers and the highest adherence. This consideration might have practical relevance when comparing escitalopram to other SSRIs and to venlafaxine and duloxetine.