Analysis of treatment patterns and persistence on branded and generic medications in major depressive disorder using...

In major depressive disorder (MDD), treatment persistence is critical to optimize symptom remission, functional recovery, and health care costs. Desvenlafaxine tends to have fewer drug interactions and better tolerability than other MDD drugs; however, its use has not been assessed in the real world.

The aim of the present study is to compare medication persistence and concomitant MDD drug use with branded desvenlafaxine (Pristiq^®) compared with antidepressant drug groups classified as 1) branded selective serotonin reuptake inhibitors (SSRIs; ie, escitalopram [Lexapro™]) and selective serotonin-norepinephrine reuptake inhibitors (SNRIs; ie, venlafaxine [Effexor^®], duloxetine [Cymbalta^®]) and 2) generic SSRIs/SNRIs (ie, escitalopram, citalopram, venlafaxine, fluvoxamine, fluoxetine, sertraline, paroxetine, and duloxetine).

MDD patients (ICD-9-CM codes 296.2, 296.3), with ≥2 prescription fills for study drugs and 12-month preindex continuous enrollment from the MarketScan Commercial Claims and Encounters Database (2009-2013), were included. Time-to-treatment discontinuation (prescription gap ≥45 days) was assessed using the Kaplan-Meier curve and Cox model. Concomitant MDD drug use was compared.

Of the 273,514 patients included, 14,379 patients were initiated with branded desvenlafaxine, 50,937 patients with other branded SSRIs/SNRIs, and 208,198 patients with generic SSRIs/SNRIs. The number of weeks for treatment discontinuation for branded desvenlafaxine were longer (40.7 [95% CI: 39.3, 42.0]) compared with other branded SSRIs/SNRIs (28.9 [95% CI: 28.4, 29.1]) and generic SSRIs/SNRIs (33.4 [95% CI: 33.1, 33.7]). Adjusting for baseline characteristics, patients who were prescribed with other branded SSRIs/SNRIs were 31% and generic SSRIs/SNRIs were 11% more likely to discontinue treatment compared with branded desvenlafaxine. In sensitivity analysis, the risk of discontinuation was within 10% of branded desvenlafaxine for branded duloxetine, generic escitalopram, and generic venlafaxine. Concomitant MDD drug use was higher among branded desvenlafaxine patients (43.8%) compared with other branded SSRIs/SNRIs (39.8%) and generic SSRIs/SNRIs (36.4%).

MDD patients on branded desvenlafaxine were more persistent with treatment compared with those on other branded or generic SSRI/SNRI therapies. Future research should include assessments of underlying factors on the treatment persistence in MDD patients.