High-dose trimipramine in acute schizophrenia. Preliminary results of an open trial.

Trimipramine and clozapine show some similarities in receptor-binding profiles. Both have the same dissociation constant for D2-receptors and marked binding potencies for H1-receptors and muscarinic acetylcholine receptors. Based on these similarities an antipsychotic efficacy of trimipramine might be postulated. To generate hypotheses 15 schizophrenic patients with a BPRS total score of at least 50 were treated with trimipramine up to 400 mg per day. Four patients deteriorated under this treatment and had to be withdrawn from the study between the 4th and the 10th day. One patient stopped participating after the 15th day due to lack of improvement. These drop-outs showed a mean impairment in BPRS total score from 56 at baseline to 66 at endpoint. Ten patients were treated for 4 to 5 weeks successfully and improved on the BPRS from 57 at baseline to 31 at endpoint. High-dose trimipramine was tolerated well. In schizophrenic patients the expected sedative effect was small. One patient developed a modest parkinsonism, no acute dystonia was seen.