Citalopram is a second generation, highly selective serotonin reuptake inhibitor (SSRI) commonly prescribed for depressive mood disorders, and is one of the most commonly prescribed antidepressant in Australia. While citalopram has a safer clinical profile than tricyclic antidepressants, adverse events and fatalities have been reported. Adverse effects of citalopram toxicity include drowsiness, somnolence, hyponatremia, dizziness, cardiac arrhythmias and tachycardia. Moreover, the combination of citalopram with monoamine oxidase inhibitors (MAOIs) may induce serotonin syndrome, and deaths due to this combination have been reported. Despite its widespread use, there are few data available on the toxicity of citalopram in autopsy populations, with most reports being restricted to case studies or small series.
Professor Johan Duflou (Department of Forensic Medicine, Sydney South West Area Health Service; School of Medical Sciences, University of New South Wales; Department of Pathology, University of Sydney).
To provide new data on citalopram toxicity by examining contributory and incidental concentrations in a large case series of fatalities in which the drug was detected in standard toxicological tests conducted as part of the medico-legal process. The study also aims to examine the toxicology of deliberate and accidental toxicity, and the presence of psychoactive substances other than citalopram.
All cases presenting to the New South Wales Department of Forensic Medicine between January 2001 and December 2010 in which citalopram was detected were retrieved for analysis.
A total of 348 cases were identified. In 48% of cases, death was deemed to be suicide. Citalopram was contributory to death in 21% of cases and incidental in 79%. Cases in which citalopram was the sole drug causing death were rare. Cases in which citalopram was contributory to death had significantly higher blood citalopram concentrations than incidental cases. Citalopram concentrations varied significantly by contributory status: sole citalopram toxicity (median=1.30 mg/L), citalopram/other drug toxicity (0.50 mg/L), incidental cases (0.30mg/L). Citalopram concentrations also varied by suicide status, with the highest concentration found in suicides where citalopram contributed to death (0.70 mg/L) compared to 0.50 mg/L for non-suicide cases where citalopram contributed to death. In almost all contributory cases other psychoactive substances were also detected, most commonly benzodiazepines, alcohol and opioids.
Darke, S., Torok, M. & Duflou, J. (in press) Contributory and incidental blood concentrations in deaths involving citalopram. Journal of Forensic Science. DOI: 10.3109/16066359.2012.672600
Provides new knowledge of the toxic concentrations of citalopram, the role of other substances and the characteristics of cases of fatal citalporam overdose.