Long-Acting Injectable Antipsychotics in the Geriatric Population: A longitudinal Study

Objective: This study compares demographic, clinical characteristics, and outcomes in older adults on long-acting injectable antipsychotics (LAI-AP) vs. oral antipsychotics (PO-AP).

Design: This observational study with a retrospective cohort utilized the electronic medical record's search engine to review charts of geriatric patients on LAI-AP for a two-year period. A convenience sample on PO-AP formed the comparison group. LAI-AP patients were subcategorized into discontinuation and continuation groups.

Setting: Conducted at an urban, psychiatric outpatient clinic, using charts from October 2020 to 2022.

Participants: Patients at least 60 years-old with psychotic or mood disorders on antipsychotics for at least 3-months during the study period.

Measurements: Demographic and clinical variables, including diagnosis, medication type, side effects, medical comorbidities, neurocognitive status, and secondary medications, were collected for both PO-AP and LAI-AP groups. Outcome variables included missed appointments, psychiatric and medical hospitalizations, and emergency room visits. Correlates of discontinuation of LAI-AP were also assessed.

Results: LAI-AP had a higher proportion than PO-AP of primary psychotic disorders (87.8% vs. 64.3%). During the study, PO-AP had higher rates of missed appointments (median 18% vs. 13% for LAI-AP) and psychiatric admissions (mean 0.019/month vs. 0.006/month for LAI-AP;); Female sex was a risk factor for discontinuation of LAI-AP (86.7% of discontinuation group vs. 55.2% of continuation group).

Conclusions: The LAI-AP group showed reduced hospitalizations, better treatment engagement, and comparable tolerability to PO-AP. Preliminary data suggests gender may influence LAI-AP discontinuation rates. This study adds to the sparse literature investigating the efficacy and tolerability of LAI-AP in geriatric patients.