Haloperidol decanoate long-acting injection (HDLAI): Results of a 1-year mirror-image study

We sought to determine clinical outcomes of the prescribing of haloperidol decanoate long-acting injection (HDLAI) at 1 year.

A 1-year mirror-image study of 84 inpatients initiated on HDLAI. Admissions and bed days in the year preceding HDLAI were compared with the year after initiation. Predictors for discontinuation were evaluated.

At 1 year, 33% of patients remained on treatment. Patients starting HDLAI because of nonadherence were more likely to stop treatment [relative risk (RR) 1.72; 95% confidence interval (CI) 1.01, 2.91; p = 0.044] whilst patients with a longer duration of illness were more likely to remain on treatment (RR 0.88; 95% CI 0.78, 1.00; p = 0.050). In the bed days cohort overall, (n = 65), there was a significant reduction in mean hospital admissions (1.4/patient/year to 0.6/patient/year; p = 0.0001) but not bed days (55.6/patient to 45.0/patient; p = 0.07) in the year following HDLAI initiation compared with the year before. Continuers had a significant reduction in mean bed days (53.1 to 4.0; p = 0.0002) and hospital admissions (1.5 to 0.2; p = 0.0001). Discontinuers demonstrated a significant reduction in hospital admissions (1.5 to 0.8; p = 0.0001) but not bed days (56.7 to 64.5; p = 0.83).

HDLAI was associated with a high treatment discontinuation rate. Hospital admissions fell in the year after HDLAI but there was no change in bed days. Our study suggests that patients with a longer duration of illness and patients initiated on HDLAI for reasons other than poor adherence may benefit from HDLAI initiation.