Quetiapine and citalopram: aetiological significances in serotonin syndrome.

The use of atypical antipsychotic medication is increasing, with an increase in reported side-effects. The first reported case of quetiapine and citalopram-associated serotonin syndrome is discussed with reference to a Medline, Embase, and PsycINFO literature search. The putative aetiological mechanism is supersensitivity of 5-HT(1A) receptors (quetiapine) within an environment of increased synaptic available serotonin (citalopram). The symptom profile of serotonin syndrome overlaps with neuroleptic malignant syndrome, but can be reliably differentiated using a time and toxicity scale.