31 Mar Does evergreening contribute to the prescribing pattern of citalopram and escitalopram to U.S. Medicaid and Medicare patients?

Parita K. Ray

Parita K. Ray

Medical Student

Department of Medical Education

Geisinger College of Health Sciences

Scranton, PA 18509

MedicalResearch.com: What is the background for this study?

• Citalopram and escitalopram are two of the most commonly prescribed antidepressants in the U.S. and are widely used for treating major depressive disorder (MDD) and generalized anxiety disorder (GAD), along with various off-label indications. While both medications share similar mechanisms of action, escitalopram was introduced as a purified version of citalopram’s active enantiomer. Despite little evidence showing a clear superiority of escitalopram over citalopram in efficacy or tolerability, prescribing trends appear to favor escitalopram, raising concerns about “evergreening”—a practice where pharmaceutical companies promote newer formulations of existing drugs to extend market exclusivity. Prior research has shown variations in the prescription rates of psychotropic medications across states and within specific populations, particularly among Medicaid and Medicare patients. However, little is known about the long-term prescribing patterns of citalopram versus escitalopram in these populations and whether these trends reflect potential evergreening practices.

MedicalResearch.com: What are the key points of your research?

• The study examined national and state-level trends in citalopram and escitalopram prescriptions among Medicaid and Medicare patients. It tested the hypothesis that citalopram prescriptions have declined over time, with a concurrent increase in escitalopram prescriptions, consistent with evergreening.
• Our findings revealed that the overall prescribing rate of escitalopram increased significantly, while the prescribing rate of citalopram declined. From 2015 to 2019, we saw -26.0% decreasing prescriptions for citalopram and +41.2% increasing rate of prescriptions for escitalopram. This shift was especially pronounced in Medicare beneficiaries, where the prescribing rate of escitalopram showed an incline over the study period. In contrast, citalopram prescriptions decreased during the same time frame.Our study also highlighted that the shift from citalopram to escitalopram was not only influenced by clinical guidelines and FDA recommendations but also reflected changes in prescriber preferences and patient outcomes. In conclusion, our research shows a clear pattern toward the increased use of escitalopram over citalopram in the Medicaid and Medicare populations, likely driven by pharmacoeconomic, clinical and demographic factors.

Figure 1. National Medicaid and Medicare population-corrected prescriptions for generic and brand name formulations of citalopram and escitalopram 2015-2020

MedicalResearch.com: Was the outcome compatible with your premise or were the results surprising?

• We hypothesized that escitalopram prescriptions would increase significantly compared to the citalopram consistent with the concept of evergreening and supported previous findings on industry-driven prescribing patterns. Our findings clearly supported this, showing a rise in escitalopram use from 32% to 57% over five years, while citalopram prescriptions decreased.
• However, regional variations were more pronounced than expected, with the Northeast showing a higher preference for escitalopram than the South. The difference between the lowest and highest prescribing states was about four-fold for escitalopram and five-fold for citalopram in Medicare. The differences were even larger among Medicaid patients with eleven-fold for citalopram and nineteen-fold for escitalopram. Treatment guidelines for psychiatric disorders do not differentiate between whether the patient resides in West Virginia versus Washington DC.
• Overall, the results were consistent with our hypothesis but the pronounced state-level differences, although consistent with prior studies with other drugs, were a surprising aspect of the data.

MedicalResearch.com: What further questions remain to be answered? What further research is indicated?

• Our study highlights trends in the use of escitalopram and citalopram, but further study is needed to explore individual-level factors that influence prescribing patterns. Understanding the reasons behind provider preferences for escitalopram over citalopram would provide valuable insight into clinical decision-making. Additionally, future research should focus on assessing patient outcomes and adverse effects associated with these medications across different regions to gain a deeper understanding of the impact of prescribing trends. It would also be beneficial to investigate how evolving clinical guidelines and insurance coverage policies influence prescribing practices for SSRIs.

Citation:

Ray PK, et al. Patterns in (es)citalopram prescriptions to Medicaid and Medicare patients in the United States: The potential effects of evergreening. Frontiers of Psychiatry 2025; https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2025.1450111/full#supplementary-material

References

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Centers for Medicare & Medicaid Services. Data.CMS.gov. Medicare Part D prescribers. Available from: https://data.cms.gov/provider-summary-by-type-of-service/medicare-part-d-prescribers

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Medicaid. Data.CMS.gov. [cited 2022 Apr 25]. State drug utilization data. Available from: https://www.medicaid.gov/medicaid/prescription-drugs/state-drug-utilization-data/index.html

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Research C for DE and. FDA. FDA; 2019 [cited 2024 Jun 16]. FDA Drug Safety Communication: Revised recommendations for Celexa (citalopram hydrobromide) related to a potential risk of abnormal heart rhythms with high doses. Available from: https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-revised-recommendations-celexa-citalopram-hydrobromide-related

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Last Updated on March 31, 2025 by Marie Benz MD FAAD