Clinical Psychopharmacology and Neuroscience Papers in Press available online.

Add-on Cariprazine in patients with long-term clozapine treatment and treatment resistant schizophrenia: Two cases of psychotic deterioration and Pisa Syndrome
Judith Weise 1, Georg Schomerus 1, Sven Speerforck 1,*
Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
An increasing number of studies deal with medical options for treatment resistant schizophrenia. If no remission can be achieved with clozapine, a combination of antipsychotics can be considered. The combination of clozapine and cariprazine is rarely studied. Cariprazine is a partial agonist on dopamine D2 and D3 receptors and a pharmaceutically rational add-on to clozapine. Stimulating D3 receptors has been linked to improved cognition and mood, with negligible extrapyramidal side effects. We present two patients with long-term treatment resistant schizophrenia receiving cariprazine and clozapine. Whereas psychotic symptoms worsened, the patients developed extrapyramidal side effects with a Pisa syndrome. The syndrome remitted after discontinuation of cariprazine. Possible explanations by pharmacodynamic interactions and drug specific receptor profiles are discussed.
Accepted Manuscript [Submitted on 2021-06-09, Accepted on 2021-09-11]