Quetiapine (Systemic), known in the United States by the brand name Seroquel®, is one of the atypical antipsychotics. Quetiapine (kwe-TYE-a-peen) has FDA and international approvals for the treatment of schizophrenia and acute mania in bipolar disorder. It is used "off-label" to treat other disorders, such as post-traumatic stress disorder, and as a sedative for those with sleep disorders.
Quetiapine is 11-[4-[2-(2-hydroxyethoxy)ethyl]-1-piperazinyl]dibenzo[b,f][1,4]thiazepine, C21H25N3O2S.
Quetiapine is a dopamine, specifically D1 and D2 dopamine inhibitor or antagonist. It also somewhat inhibits functioning of serotonin receptors, but in clinical tests it has been found that the human body is very adaptive to the serotonine blocking reaction, thus it can be used together with SSRI medication.
Quetiapine is believed to be less likely to cause tardive dyskinesia than typical antipsychotics. However, as with other antipsychotics, there is evidence implying that quetiapine may cause tardive dyskinesia.
Studies conducted on beagles have resulted in the formation of cataracts, however, there has been no report describing this effect within humans. Common side effects include: agitation, memory problems, sedation, and an upset stomach. More information on side effects can be found at NIH's profile of the medication.