To describe the types of psychotropic drugs ingested during intentional drug overdose (IDO) in subjects consecutively admitted to an emergency department and to assess which ones were a prognostic factor associated with increased morbidity during hospitalization.

Demographic characteristics, psychiatric history, current drug treatment, characteristics of the IDO were collected for 1654 patients admitted for IDO with psychotropic drugs (anxiolytics, hypnotics, antidepressants, antipsychotics and mood stabilizers). IDOs were a priori categorized as serious if associated with at least one of the following outcomes or technical events: death, hospitalization in the ED longer than 48 hours, respiratory support, use of vasopressive drugs, cardiac massage or dialysis. All types of psychotropic drugs were entered into a logistic regression model adjusted for age and gender. A stepwise selection was used to assess the types independently associated with serious IDO. Then, numerous confounding variables were entered one at a time in the final model.

Nearly all the patients ingested psychotropic medications during the IDO (88.4%), most often benzodiazepines (71.6%), and half used at least two various psychotropic products. Serious IDO was associated with tricyclics (OR 5.7; 95%CI 3.3-9.8), lithium (OR 4.3; 95%CI 1.6-11.6), carbamates (OR 2.7; 95%CI 1.8-4), anticonvulsants (OR 2.4: 95%CI 1.4-4.3), first-generation antipsychotics (OR 2.4; 95%CI 1.7-3.5) or selective serotonin reuptake inhibitors (OR 1.6; 95%CI 1.1-2.3).

Some drugs may be dangerous because of low toxic doses; prescriptions of short duration may be recommended. Moreover, for safety reasons, prescribers may prefer SSRIs to tricyclics and benzodiazepines to carbamates or phenothiazines.