Oral fluid venlafaxine and clozapine levels for therapeutic drug monitoring

Introduction:

Therapeutic drug monitoring (TDM) is becoming increasingly important in the medical treatment of childhood and adolescent psychiatric disorders. Particularly in the case of mentally unstable patients and children, the question arises as to whether there is a painless alternative to sampling. Salivary testing can help to significantly improve patient cooperation and quality of therapy. This study gives an overview of the current state of the literature and shows the results of our own investigations.

Methods:

In this study, drug levels in serum and saliva were compared to determine if saliva is a new matrix.

For this purpose, both patient serum and saliva were taken. The concentrations of venlafaxine, clozapine and their metabolites, measured in saliva and serum, were measured by LC-MS.

Results:

All substances in the saliva could be determined very well, with some very good correlations to the serum value. Repeated measurements in saliva for 10 consecutive days showed that these results are heterogenious interindividually, but very stable intraindividually, so that saliva measurements could be used for follow up measurements.

Conclusion:

From the results to date it can be concluded that therapeutic drug monitoring from saliva may be a viable and cost-effective alternative to serum TDM.