2025 Southeastern Residency Conference

Title: 
Prevalence, Incidence, and Outcomes of Selective-Serotonin Reuptake Inhibitor (SSRI) and Serotonin-Norepinephrine Reuptake Inhibitor (SNRI) Duplication of Therapy 


Authors:
Gabrielle E. Hall, Aaryn Brewster, Cameron Lanier


Objective:
Identify the prevalence, incidence, and associated outcomes of duplicative prescribing and ordering of SSRI and SNRI therapy at three regional hospitals within a regional health system. 


Self Assessment Question:
What percentage of patients on SSRI or SNRI therapy at baseline were prescribed or ordered duplicative therapy while admitted to a study hospital during the research period?


Background: 
Multiple patients have been identified as having been prescribed or ordered duplicative SSRI and SNRI therapy. This is not a guideline recommended therapy due to the increased risk for adverse events, specifically serotonin syndrome, resulting from using multiple serotonergic agents in combination. Our goal is to identify how often these duplications are occurring and to promote patient safety through recommending appropriate prescribing practices.  


Methods:
This is a retrospective chart review with subgroup analysis. The patient population consists of patients exposed to either two SSRIs, two SNRIs, or an SSRI and SNRI combination while inpatient. Patients were divided into two groups based on those on duplicative therapy prior to admission and those who started on duplicative therapy during admission.  
The primary outcome for this study is prevalence of duplications of therapy as compared to those on SSRI or SNRI at baseline. The secondary outcome is incidence of duplications of therapy as compared to those on an SSRI or SNRI at baseline. Further secondary outcomes of the study include a logistic regression analysis comparing the exposure group to the control group to assess outcomes including similarities and differences in their baseline demographics and reported adverse events. 


Results:
The primary outcome for this study was prevalence of duplications of therapy where out of 7545 patients on an SSRI or SNRI at baseline 152 patients (2%) were on duplicative therapy. The secondary outcome of incidence of duplications of therapy revealed 81of the of 7545 patients (1%) on an SSRI or SNRI at baseline were started on duplicative therapy inpatient. Of the 152 patients on duplicative therapy, 81 patients (53%) were initiated on those duplicate agents while inpatient. Another finding includes 588 patients out of 7545 patients (8%) on an SSRI or SNRI at baseline were on multiple serotonergic agents.  Frequently duplicated medications include escitalopram with duloxetine (40/152, 26%), sertraline with duloxetine (40/152, 26%), and fluoxetine with duloxetine (19/152, 12.5%). Duloxetine was found to be a duplicated medication in 111 of 152 patients (73%).