A 52-week open-label study of the safety and tolerability of paliperidone palmitate in patients with schizophrenia.

The safety and tolerability of paliperidone palmitate, an injectable atypical antipsychotic agent, were assessed in a 1-year open-label extension of a double-blind study in patients with schizophrenia. Patients from the double-blind study who experienced a recurrence, remained recurrence free until study end, or who were in the transition, maintenance or double-blind phases and had received at least one injection of paliperidone palmitate when enrollment was stopped, were eligible for the open-label extension. Patients received gluteal injections of paliperidone palmitate once every 4 weeks: starting dose 50 mg eq. followed by 25, 50, 75, or 100 mg eq. flexible dosing. Of the 388 patients enrolled, 288 completed the open-label extension. During the open-label extension, the median (range) duration of exposure to paliperidone palmitate was 338 days (10; 390), and 74% of patients received all 12 open-label injections of paliperidone palmitate. The most frequent (≥ 5% in total group) adverse events were insomnia (7%); worsening of schizophrenia; nasopharyngitis; headache; and weight increase (6% each). Potentially prolactin-related adverse events occurred in 13 (3%) patients, mostly women, and none resulted in study discontinuation. Extrapyramidal treatment-emergent adverse events were reported in 25 (6%) patients; tremor was the most frequently reported (n = 8, 2%). At open-label extension endpoint, investigator-rated redness at the injection site was observed in ≤ 4% of patients in each group. Injection-site pain was rated by investigators as absent in 82-87% of patients. Schizophrenia symptoms measured by Positive and Negative Syndrome Scale and personal and social performance changes improved during the open-label extension.