Clozapine combined with different antipsychotic drugs for treatment resistant schizophrenia.

Although clozapine has been shown to be the treatment of choice in people with schizophrenia that are resistant to treatment, one third to two thirds of people still have persistent positive symptoms despite clozapine monotherapy of adequate dosage and duration. The need to provide effective therapeutic interventions to patients who do not have an optimal response to clozapine is the most common reason for simultaneously prescribing a second antipsychotic drug in combination with clozapine.