The economic impact of introducing serotonin-noradrenaline reuptake inhibitors into the Brazilian national drug formulary: Cost-effectiveness and budget-impact analyses

Objective: To determine the cost effectiveness, from the Brazilian Ministry of Health viewpoint, of three antidepressant classes for major depressive disorder (MDD), and the budget impact of introducing serotonin-noradrenaline (norepinephrine) reuptake inhibitors (SNRIs) into the current Brazilian national drug formulary, assuming a 6-month treatment duration. Methods: An existing decision-tree model was adapted to Brazil, based on local guidelines. Clinical data were obtained from published meta-analyses. Patients included adults aged ≥18 years with MDD, diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, third and fourth editions (DSM-III/IV), with moderate-to-severe disease (Hamilton Depression Rating Scale [HAMD] ≥15 or Montgomery-Åsberg Depression Rating Scale [MADRS] ≥18), without co-morbidities or co-medications, receiving ≥6 weeks of treatment with SNRIs, selective serotonin reuptake inhibitors (SSRIs) and/or tricyclic antidepressants (TCAs). Clinical ou