Amoxapine shows atypical antipsychotic effects in patients with schizophrenia: results from a prospective open-label...

Amoxapine is marketed as an antidepressant. However, its receptor occupancy, in vitro and in vivo, and its effects in pre-clinical models are very similar to atypical antipsychotics. To examine if this leads to an atypical antipsychotic effect in the clinical context, the authors examined the antipsychotic and side-effect profile of amoxapine in acutely psychotic patients with schizophrenia.

Seventeen patients were enrolled and 15 completed a prospective open-label 6-week study of amoxapine starting with a fixed-starting dose (150 mg/h) with standardized titration up to 250 mg/h, if required. Positive, negative, affective symptoms and side-effects were monitored using standardized weekly assessments.

Amoxapine (median final dose 210 mg/h) was well-tolerated and showed significant improvement in positive and negative symptoms (both p<0.001), with a trend towards improvement in mood symptoms and no treatment-emergent extrapyramidal side-effects, akathisia or weight gain. Prolactin elevation was observed.

These clinical data lend support to the pre-clinical suggestions that amoxapine may be an atypical antipsychotic. Given its lack of weight gain and that it is considerably less expensive than current options, amoxapine could be a valuable alternative for some patients. These considerations strongly call for more systematic, double-blind studies of amoxapine as an atypical antipsychotic.