Antipsychotic dose in maintenance treatment of schizophrenia: A retrospective study

The dose of antipsychotic required for acute phase treatment of schizophrenia is well established, but there is no consensus on dose required for maintenance phase. Current guidelines do not provide definitive recommendations on the dose of antipsychotics needed in the maintenance treatment of schizophrenia, possibly due to limited research. In this retrospective study, minimum antipsychotic dose prescribed in maintenance treatment of schizophrenia in a real life situation was examined. Schizophrenia patients having Clinical Global Impression - Severity (CGI-S)≤3 for at-least six months during the maintenance phase treatment were included (n=163). The medical records of these patients were reviewed and the antipsychotic dose prescribed for acute and maintenance phase treatment was recorded. The mean antipsychotic dose used during maintenance treatment was approximately 30% lower than the dose used during acute phase. Importantly, about 40% of the subjects maintained well with a dose lesser than the recommended therapeutic range. Earlier age at onset and longer duration of illness were associated with higher antipsychotic dose requirement during the maintenance phase treatment. These findings could have important clinical implications if replicated in systematic prospective studies.