Switching stable patients with schizophrenia from depot and oral antipsychotics to long-acting injectable risperidone: reasons for switching and safety.

OBJECTIVE: An international, non-randomised study evaluated efficacy and safety of risperidone long-acting injectable (RLAI) compared to previous treatment. To investigate generizability of the European data set to the UK subset safety and switching data are reported here.

METHODS: Patients with schizophrenia or other psychotic disorder, symptomatically stable on antipsychotic medication, received intramuscular injections of RLAI 25 mg (to a maximum of 50 mg) every 2 weeks for 6 months.

RESULTS: Of 182 UK patients enrolled, 79% had schizophrenia, 21% other psychotic disorders. Insufficient efficacy (43%), side effects (45%), and non-compliance (25%) were the most common reasons for switching. Sixty-nine per cent of patients completed the trial; 8% discontinued due to adverse events (AEs). Most frequent treatment-emergent AEs were headache (8.2%), relapse (7.7%) and insomnia (7.1%); 8 (4.4%) patients reported injection-related AEs. There were significant improvements in extrapyramidal symptom rating scale total and subscale (particularly Parkinsonism) scores, regardless of previous medication (total cohort, p < or = 0.0001). There was a small but significant increase in body weight at endpoint (1.2 kg, p = 0.0023). One patient suffered a myocardial infarction and died (not treatment-related). There were no substantial differences between the full data set and the UK sub-population

CONCLUSION: Switch to RLAI was well-tolerated in stable patients over 6 months. The European data set is generalizable to the UK patient population.