Acute medical costs of fluoxetine versus tricyclic antidepressants. A prospective multicentre study of antidepressant drug overdoses.

Abstract

Despite demonstrated differences in toxicity profiles between tricyclic antidepressants (TCAs) and selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs), no studies have examined hospital costs associated with acute antidepressant overdoses. Given the high incidence of such overdoses, it is important to examine treatment patterns and associated costs. This prospective, multicentre cohort study compared the hospital and physician costs associated with TCA and fluoxetine drug overdoses. Over a 30-month period, 622 consecutive patients with a fluoxetine or TCA overdose presented to the emergency departments, or were admitted to intensive care or medical units, of 9 participating medical centres across the US. Inclusion criteria were: ingestion of a single antidepressant (fluoxetine or a TCA), without clinically significant co-ingestants; laboratory confirmation of the overdose; and retrievable hospital bills. Patients were followed until discharge from the emergency department or hospital. Hospital and physician charges were collected from billing data. Hospital charges were adjusted using Health Care Financing Administration cost: charge ratios to estimate costs; physician charges were adjusted to estimate costs. Patient demographic and clinical data were prospectively gathered during the course of medical treatment. Clinical data recorded included level of consciousness, cardiopulmonary complications, vital sign or ECG abnormalities, agitation, seizures, CNS depression and death. 136 patients (121 with TCA overdose and 15 with fluoxetine overdose), representing 21.8% of the 622 patients entered, met the inclusion criteria. Mean length of stay varied from 0.73 [+/-standard error of the mean (SEM) 0.33] days for fluoxetine overdose patients to 3.59 (+/-SEM 0.48) days for TCA overdose patients (p = 0.038). Mean hospital costs were $US668 for patients with a fluoxetine overdose compared with $US4691 for those with a TCA overdose (p < 0.0001). No significant differences were observed between the TCA and fluoxetine overdose groups with regard to physician costs. Median hospital and physician costs increased from $US3029 to $US4396 from the first 15-month period of the study to the second 15-month period of the study for the TCA overdose group, but decreased from $US881 to $US396 for the fluoxetine overdose group. Patients with fluoxetine overdoses had lower hospital and total medical costs compared with patients with TCA overdoses. There was some evidence supporting a reduction in the medical costs of treating fluoxetine overdoses over the 30-month study period.