Recurrent toxic delirium in a patient treated with SSRIs: is old age a risk factor?

We present the case of a 71-year-old female suffering from bipolar affective disorder type 2 and an old lacunar brain infarct who, under the combined treatment of fluoxetine for depression and low dose trazodone for the accompanying insomnia, developed a toxic delirium. The subject presented with mental state changes (confusion and agitation), hyperreflexia, diaphoresis, nausea, vomiting, fever, and a general tonic-clonic seizure which developed soon after an increase in the trazodone dose. One year prior to the above episode, she was hospitalized for a transient episode of agitated confusion while being treated with fluvoxamine for depression, alprazolam and brotazolam for the accompanying anxiety and insomnia. Both episodes subsided spontaneously when treatment was discontinued. This case reports the possible existence of increased vulnerability to hyperserotonergic states in elderly patients suffering from concomitant psychiatric and neurological disorders.