Citalopram distribution in postmortem cases

This is a report of the analytical findings in 13 cases investigated by either the Office of the Chief Medical Examiner, State of Maryland or the Bexar County (San Antonio, TX) Medical Examiner's Office in which citalopram, a highly selective serotonin reuptake inhibitor used therapeutically as an antidepressant, was identified. In 8 of the 9 cases in which both blood and urine specimens were received, the urine citalopram concentration exceeded the blood concentration, indicating that urine is an appropriate specimen for screening citalopram use. The average liver to blood citalopram concentration ratio was 6.5 (range 3.1-13, n = 6). Three cases had blood concentrations less than 0.24 mg/L, which is in the reported antemortem therapeutic range of the drug. Eleven cases had blood concentrations less than 1.3 mg/L; in each of these cases, citalopram was determined to be an incidental finding to the ultimate cause of death. Quantitation of citalopram and the metabolite desmethylcitalopram in these cases yielded an average parent-to-metabolite ratio of 6.4.