The Clinical Use of Antipsychotic Plasma Levels

Jonathan M. Meyer is a Clinical Professor of Psychiatry at the University of California, San Diego, and a Psychopharmacology Consultant to the California Department of State Hospitals. Stephen M. Stahl is Adjunct Professor of Psychiatry at the University of California, San Diego, Clinical Professor of Psychiatry and Neuroscience at the University of California, Riverside, and Honorary Visiting Senior Fellow in Psychiatry at the University of Cambridge.

• Preface; Introduction; 1. Sampling times for oral and long-acting injectable agents; 2. The therapeutic threshold and the point of futility; 3. Level interpretation including laboratory reporting issues, responding to high plasma levels, special situations (hepatic dysfunction, renal dysfunction and hemodialysis, bariatric surgery); 4. Tracking oral antipsychotic adherence; 5. What is an adequate antipsychotic trial – using plasma levels to optimize psychiatric response and tolerability; 6. Important concepts about first generation antipsychotics; 7. Haloperidol and haloperidol decanoate; 8. Fluphenazine and fluphenazine decanoate; 9. Perphenazine and perphenazine decanoate; 10. Zuclopenthixol and zuclopenthixol decanoate; flupenthixol and flupenthixol decanoate; 11. Chlorpromazine, loxapine, thiothixene, trifluoperazine; 12. Important concepts about second generation antipsychotics; 13. Clozapine; 14. Risperidone oral and long-acting injectable, paliperidone oral and long-acting injectable; 15. Olanzapine and olanzapine pamoate; 16. Aripiprazole, aripiprazole monohydrate and aripiprazole lauroxil; 17. Amisulpride, asenapine, lurasidone, brexpiprazole, cariprazine; Appendix Therapeutic threshold, point of futility, AGNP/ASCP laboratory alert level, and average oral concentration-dose relationships.

'As we redouble our efforts to achieve the goals of personalized medicine, therapeutic drug monitoring (TDM) can play a critical role. Individuals vary enormously in how they absorb and metabolize different medications and which impactful environment factors or co-occurring conditions they might encounter. In my view, the potential value of the knowledge that can be provided by TDM has been given less attention than it deserves. Meyer and Stahl have done an excellent job of reviewing this topic. They address all necessary perspectives, from optimizing response and tolerability to better monitoring of adherence and help to explain idiosyncratic or unexpected medication effects, as well as the timing and interpretation of plasma levels. This is an extremely useful text for anyone involved in the use of antipsychotic drugs.' John M. Kane, Professor and Chairman, Department of Psychiatry, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell