Augmentation of Clozapine With Paliperidone in Schizophrenia Patients With Partial Response to Treatment: A Case Series

Clozapine is the only antipsychotic which has definitely shown to be effective in refractory schizophrenia. Clozapine treatment is usually preferred in schizophrenia patients with a partial response to treatment and augmentation strategies are tried when clozapine also fails to provide full treatment response. In treatment resistant schizophrenia patients addition of a second antipsychotic is a frequently preferred augmentation method. With previous augmentation strategies consistent positive results could not be obtained. Paliperidone is a risperidone metabolite and it has proven effectiveness in schizophrenia treatment. Although most effects of paliperidone on central nervous system are similar with risperidone, there are some differences. In this case series treatments of 5 schizophrenia patients who still had symptoms despite clozapine treatment were augmented with paliperidone during 6 months of follow up. This augmentation was tolerated well by the patients, and caused improvements in both positive and negative symptoms. Particularly, improvement in negative symptoms after addition of paliperidone was remarkable in our patients. Evaluation of paliperidone's effects on negative symptoms in schizophrenia patients with partial response to clozapine treatment using randomized, placebo controlled studies may provide an important treatment choice.