In our clinical practice we can be forced, in few cases, to switch from aripiprazole to other antipsychotics due to recurrence of symptoms of schizophrenia. We don’t have much information about the influence of aripiprazole on the onset of action of new antipsychotic.

The action of antipsychotics starts in first two or three weeks. Switch from one antipsychotic to another can influence the onset of action of the last.

Aripiprazole has a strong affinity for D2 receptors (bounded on more than 90% of D2 receptors in therapeutic doses) and a half time of 72 hours. The access to D2 receptors after aripiprazole can be delayed.

We had two case studies, both diagnosed with schizophrenia, multiple episodes, currently in acute episode according to DSM V. Both patients were treated with aripiprazole in the past year, uptitrated to 30mg/day in the last month due to recurrence of positive symptoms. because of persistence of positive symptoms, the patients were switched to olanzapine and respectively to risperidone.

The symptoms of both patients were persistent for 5 weeks. After that time, both patients have a good response to the new antipsychotic. PANSS score had a reduction on positive items only after five weeks after the switch, which means a delay of action of new antipsychotic.

We presume that aripiprazole can delay, in same cases, the onset of action, if switched to another antipsychotic due to persistence in the plasma (long halftime) and his superior affinity for D2 receptors.