Paliperidone palmitate: factors predicting continuation with treatment at 2 years

Our aim was to determine factors relating to continuation with treatment with paliperidone palmitate long-acting injection (PP) in a 2 year, non-interventional, observational study of the use of PP in consecutive patients treated in a secondary care environment. We followed-up 300 consecutive patients; 24 (8%) were lost to follow-up (7 deceased and 17 left the care of the trust). Overall, 107 patients of the remaining 276 who were not lost to follow-up (38.7%) completed 2 years' continuous treatment. A further 21 (7.6%) patients discontinued PP but restarted it after >2 months, 11 (4.0%) of whom were still receiving PP at 2 years. Median treatment time for PP was 465 days (95% CI 333, 583 days). Prior treatment with risperidone reduced the risk of discontinuation by 39% (RR 0.61 (95% CI -0.44, 0.86, p=0.004)); being initiated as an out-patient by 49% (RR 0.51 (95% CI 0.36, 0.73 p=0.001)). Risk of discontinuation was increased by 63% when the reason for prescribing PP was poor tolerability of prior treatment (RR 1.63 (95% CI 1.05, 2.51 p=0.028)). The rate of continuation with PP at 2 years was higher than that seen with other long acting depot formulations. Likelihood of continuation can be vastly improved by targeting PP for those most likely to benefit.