[A new atypical antipsychotic with partial dopamine agonist effect (aripiprazole)]

Aripiprazole act as a partial agonist on the D2 receptors in contrast to the other antipsychotic agents which exert a pure antagonist action. In the autoreceptors with large receptor reserve aripiprazole shows primarily agonistic action, while postsynaptically its antagonistic action becomes predominant. In addition aripiprazole is an antagonist at the 5-HT2A, receptor and a partial agonist on the 5-HT1 receptor. On the basis of these receptor actions it is suggested that aripiprazole works as a stabilizer of both the dopaminergic and serotoninergic systems. Probably due to this dual stabilizing effect aripiprazole ameliorates positive and negative as well as anxiety and cognitive symptoms. Especially the very rare extrapyramidal symptoms, prolactine level elevation, QT-interval lengthening and absence of severe body weight increase and metabolic disturbances are noteworthy, which all seriously impair the health condition, the quality of life and the therapy adherence of the patients. Due to the very low affinity of aripiprazole to the H1 and muscarinic receptors aripiprazole practically does not lead to increase of body weight. The significant clinical efficacy coupled with good tolerability assures high level clinical effectiveness for aripiprazole in the broad clinical practice.