The role of atypical antipsychotics in the treatment of delirium

Delirium exemplifies the interface between medicine and psychiatry. It is generally characterized by acute disturbances of consciousness, cognition, and perception that are precipitated by an underlying medical condition. The gold standard of psychiatric treatment is to treat the underlying medical cause and use high-potency antipsychotics to treat the clinical manifestations of delirium. In the early 1990s, a new generation of novel antipsychotics was developed. Their mechanism of action, preferential serotonergic (5HT(2a)) blockade, results in a markedly lower rate of extrapyramidal side effects, an advantage over the typical, older antipsychotic medications. These agents have been shown to be effective and well tolerated in common psychotic disorders (e.g., schizophrenia or bipolar disorder), but few studies have evaluated them in the treatment of delirium. This paper reviews the pertinent literature and summarizes tentative guidelines for novel antipsychotic use in delirium.