A dopamine excess is thought to be involved in positive psychotic symptoms in schizophrenia. All current antipsychotics show a degree of dopamine receptor antagonism. Little is known about the differential effectiveness of different antipsychotics in treating specific sets of symptoms. We report the case of a 35-year-old man with schizophrenia who presented with prominent hallucinatory symptoms (Positive and Negative Syndrome Scale [PANSS] P1=5, P3=5, P6=5) resistant to high doses of a dopamine, serotonin receptor antagonist, olanzapine. Switching from olanzapine to zuclopenthixol, a dopamine D2 receptor antagonist, led to a complete shift of his symptomatology: his hallucinations abated, however, he presented as very highly paranoid (PANSS P1=6, P3=2, P6=7). On a combination of both antipsychotics, his symptoms subsided (PANSS P1=3, P3=2, P6=2). We discuss the potential for differential effectiveness of different antipsychotic medications in treating hallucinations and paranoia. We argue that future studies could address this question by stratifying patients based on symptoms.
Keywords: psychiatry; schizophrenia; therapeutic indications.
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