Antipsychotic treatment strategies for acute phase and treatment resistance in schizophrenia: A systematic review of the guidelines and algorithms

Background: To summarize the current state of knowledge on antipsychotic treatment strategies for the acute phase and treatment resistance in schizophrenia, we conducted a systematic review of guidelines and algorithms. Methods: We conducted a systematic literature search to identify clinical guidelines and algorithms on this topic using MEDLINE and Embase. We extracted information on recommendations for antipsychotic treatment strategies, including those for non-response (i.e., increasing antipsychotic dose and switching to another antipsychotic) and treatment resistance. Results: We identified a total of 17 guidelines/algorithms in various countries that were published after 2011. With respect to antipsychotic dose, most of the guidelines (N = 10/11) agreed starting with a low dose or the lowest licensed/effective dose and then titrating the dose upwards. Regarding antipsychotic treatment strategies for non-response, all of the guidelines (N = 9/9) recommended increasing antipsychotic dose towards the upper end of its approved dose range. Five guidelines suggested for increasing beyond the therapeutic dose range in exceptional cases, while overall 10 guidelines including them were negative about such strategy. The vast majority of guidelines (N = 16/17) recommended switching to another antipsychotic for non-response; however, some guidelines mentioned the lack of evidence for these strategies other than the use of clozapine. All the guidelines (N = 17/17) endorsed initiating clozapine after failure to respond to 2 different antipsychotics. Four guidelines endorsed an early use of clozapine, yet as the third antipsychotic. Conclusion: The currently available guidelines and algorithms recommended increasing antipsychotic dose and switching to another antipsychotic, particularly clozapine for treatment-resistant schizophrenia, during the acute phase of schizophrenia for non-response.