A Safety and Tolerability Study of Paliperidone Palmitate Injected in the Shoulder or the Buttock Muscle in Patients With Schizophrenia

• Pharmacokinetic evaluations (e.g. blood level of the drug) at finish of trial
• Efficacy measures at finish of trial

The purpose of this study is to evaluate the safety and tolerability of intramuscular injections (to the buttocks or to the shoulders) of paliperidone palmitate in patients with schizophrenia.

To date, all prior trials involving intramuscular injection of paliperidone palmitate were conducted with buttock administration. This is a randomized, multicenter, crossover design study in evaluating safety and tolerability of paliperidone palmitate in two different injection sites. The study hypothesis is that there will be no difference in safety and tolerability between buttock injection compared to shoulder injection at any of the three different doses of paliperidone palmitate. The patients will receive intramuscular injections of paliperidone palmitate in either their buttocks or in their shoulders

Inclusion Criteria:

• The patient must have signed an informed consent
• The patient must meet the diagnostic criteria for schizophrenia
• Female patient must be postmenopausal for at least 2 years or have negative pregnancy test result at screening
• The patient must be able to perform study requirements (e.g. answer questionnaire)

Exclusion Criteria:

• Primary, active diagnosis other than schizophrenia
• Psychiatric inpatient hospitalization for relapse of symptoms of schizophrenia in the past 90 days
• Change in their antipsychotic medication in the past 45 days
• Diagnosis of active substance dependence within 3 months
• History of treatment resistance
• History of concurrent significant or unstable diseases (e.g. heart, lung, or liver diseases)