Antidepressant switching patterns in the elderly

ABSTRACTBackground:Switching between antidepressants is complex due to potential adverse outcomes such as serotonin syndrome and antidepressant discontinuation syndrome, yet switching is often required due to non-response to initial treatment. This study aimed to examine the patterns and extent of antidepressant switching in a cohort of older adults in long-term residential care.

A cohort study of medication supply data from 6011 aged care residents in 60 long-term care facilities was conducted. Incident antidepressant users were followed for 12 months and their patterns of antidepressant use determined. The type of switching from and to different antidepressant classes was determined according to National and International recommendations for antidepressant switching.

In total, 11% (n = 44) of the residents were initiated on an antidepressant medication (n = 402) switched to a different antidepressant agent within 12 months. Residents commenced on a SNRI or TCA were most likely to switch antidepressants (17% in each group). Almost half of the switches (n = 21, 48% of all switches) were not implemented according to guideline recommendations. Direct switch and taper followed by wash out and switch, accounted for all of the inappropriate switching (29% and 71%, respectfully), with half occurring to mirtazapine (N = 7) or from mirtazapine (N = 3).

Over one in 10 long-term aged care residents who commence an antidepressant will switch to a different antidepressant within 12 months. Current antidepressant switching practices in long-term residential aged care may be increasing the risk of harm associated with antidepressant switching, with around half of all switches not following current guideline recommendations.