Quetiapin in bipolar disorders

: Atypical antipsychotics are now widely used in the acute and long-term treatment in bipolar disorder. The role of atypical antipsychotics as acute agents, add-on medications; or as primary mood stabilizers in different phases of bipolar disorder is an important current research tendency. However, in bipolar disorder the mostly used indication of quetiapine is the management of acute manic phases, clinical data and the actual research results suggest that it may have both antidepressant and long-term antimanic effects. Quetiapine enhances the transmission of the central serotonergic networks, by its high antagonistic affinity for 5-HT(2A) and partial agonistic activity for the 5-HT(1A) receptors. The 5HT(1A) partial agonism causes an increase in the dopaminergic neurotransmission of the prefrontal cortex, and also, the affinity for the alpha 2-adrenoceptor brings a relative increase in extracellular noradrenergic release an tone in the prefrontal cortex. Latest research shows that quetiapine's main, active, human plasma metabolite, N-desalkyl quetiapine (norquetiapine), has a high inhibition affinity for the noradrenergic transporter. These data suggest that comparing to other atypical antipsychotics, norquetiapine may have a relatively strong antidepressant potential. Modifying the dopaminergic transmission by quetiapine's D2 receptor blocking activity results indirect mediating the cAMP-PKA and the arrestin-Akt-GSK-3 intracellular signal transduction pathways, which process may explain its long-term antimanic and mood stabilizing capability. Quetiapine's activity on nerve growth factors, histamine H1 receptor, proinflammatory networks may take an important additional part in its efficacy in bipolar depression. Its very fast dissociation from the D2 receptor is an important pharmakokinetic parameter for managing the optimal quetiapine dose in the daily clinical practice. This review tries to organize the actual information on quetiapine's multiplex activity in bipolar disorder.