A compilation of serum concentrations of 12 antipsychotic drugs in a therapeutic drug monitoring setting

Introduction A comprehensive collection of routine therapeutic drug monitoring (TDM) data for antipsychotic drugs can support the physician when individualizing dosing and determining treatment strategies for the specific patient.

Methods The compilation consists of TDM-data from twelve antipsychotics substances. The drugs included are amisulpride (n=506), aripiprazole (n=1610), clozapine (n=1189), flupentixol (n=215), haloperidol (n=390), olanzapine (n=10268), perphenazine (n=1065), quetiapine (n=5853), risperidone (n=3255), sertindole (n=111), ziprasidone (n=1235) and zuclopenthixol (n=691). As only one sample per patient is included the number of patients equals the number of samples. For each drug median serum concentrations as well as 10th and 90th percentiles are given for a range of daily doses. Comparisons are made between males and females, between patients younger and older than 65 years of age and between those treated with a low and a high dose of each drug. The concentration-to-dose (C/D) ratio is the primary variable used in these comparisons. Within and between subject variation (CVs) for the serum concentrations of each drug are presented.

Results In general, the C/D ratios were higher in females than in males, were higher in those older than 65 years of age than in younger subjects and were lower in those treated with higher doses than in those treated with lower doses. CVs between individuals were larger than within subjects, and the CVs were highest for the drugs with short elimination half-lives.

Conclusions For each antipsychotic drug the results presented can serve as a reference tool for pharmacokinetic interpretation of the individual patient’s serum drug level.

Publication History

Article published online:
16 May 2022