Relapse and frequency of injection of monthly paliperidone palmitate—A retrospective case–control study

BACKGROUND: Outcomes with long-acting injections (LAIs) are generally better than with oral antipsychotic therapy. However, the use of LAIs does not assure compliance with treatment and in clinical practice patients often miss injections or receive their injections later than intended. METHOD: We conducted a case–control study to identify demographic and treatment associations with relapse (cases) on paliperidone 1-monthly injection (PP1M) compared with age-, gender-, and ethnicity-matched controls. RESULTS: We identified 16 cases and matched 43 controls. Baseline variables did not differ except that cases had received significantly more antipsychotic drugs before initiation with PP1M (3.94 vs. 2.12; p < 0.001). Cases had fewer PP1M injections administered compared with the control group (9.69 vs. 11.37; p < 0.001) and this group had a longer interval between injections than the control group (37 vs. 33 days; p < 0.001). CONCLUSIONS: Relapse on PP1M is associated with reduced frequency of injection and a longer interval between doses.