Aripiprazole: profile on efficacy and safety

Aripiprazole (Abilitat, Bristol-Myers Squibb) is the most recent addition to the new class of atypical antipsychotic medications, following the release of clozapine, risperidone, olanzapine, quetiapine and ziprasidone. Aripiprazole exhibits typical antagonism at dopamine (D2) receptors in the mesolimbic pathway, as well as having unique partial agonist activity at D2 receptors in the mesocortical pathway. As exemplified by other atypical antipsychotics, it displays strong 5-HT(2a) receptor antagonism and is similar to ziprasidone in also having agonistic activity at the 5-HT(1a) receptor. Among the atypical antipsychotics, aripiprazole displays the lowest affinity for alpha(1)adrenergic (alpha(1)), histamine (H1) and muscarinic (M1) receptors. This combination of effects may be responsible for its efficacy in positive and negative symptoms of schizophrenia and in bipolar disorder. Similarly, this profile may be the reason for the low rates of reported side effects observed. This includes general adverse events, a low incidence of reported weight gain and a low liability for inducing movement disorders. Other early data suggest that aripiprazole may induce reductions in plasma prolactin, as well as in plasma glucose and lipid profiles. Finally, results also support the proposition that aripiprazole may lead to reductions in corrected QT interval and have minimal drug interactions.