Objective
Concurrent polypharmacy and potentially-inappropriate-medication (PIMs) use with antidepressants in older adults is understudied. We investigated the prevalence and associated user characteristics of concurrent polypharmacy (≥5 drugs) and PIMs with antidepressants in all older adults (≥65 years) in Denmark based on prescriptions filled at community pharmacies during 2015–2019.

Method
We applied a cross-sectional and cohort study design using socio-demographic and clinical data from Danish registers.

Results
A total of 261,479 older adults (mean age 76 years, females 63%) redeemed at least one prescription of antidepressants during 2015–2019. The prevalence of polypharmacy was 73%, and PIMs was 56%, with over 80% using at least one other nervous system drug or cardiovascular system drug concomitantly with antidepressants. Characteristics associated with higher concurrent use of polypharmacy and PIM with antidepressants were older age, marital status as widow/widower/separated/single, place of residence predominantly in the rural regions, non-western origin, and having somatic diagnoses. Some characteristics showed opposite directions of the associations with the two outcomes, including previous antidepressant use and psychiatric diagnoses being associated with higher use of polypharmacy but lower use of PIM.

Conclusion
High polypharmacy and PIM use with antidepressants underline the importance of regularly reviewing pharmacological treatments in older adults with depression.