Therapeutic drug monitoring of clozapine: an unexpected outcome.

A patient is described who died with the diagnosis of septicemia. After her death the delayed results of a clozapine determination for TDM were sent to the clinician. The clozapine serum level was 4034 microg/L, which was considered to be the primary cause of death. However, a forensic autopsy revealed unexpected metastases of unknown origin with gross liver involvement. Thus the high clozapine levels were judged to be secondary to liver failure. This case is an example of an unexpected outcome of TDM.