Problem-solving tool
“The therapeutic reference range for antipsychotic levels in blood consists of a lower limit, below which therapeutic response is relatively unlikely, and an upper limit, above which ADRs [adverse drug reactions] … are more likely to occur,” the authors wrote.
TDM can determine whether a patient has a subtherapeutic antipsychotic blood concentration and may explain a lack of response or a supra-therapeutic concentration, which could be associated with adverse drug reactions.
“It is important for clinicians to realize that this type of monitoring is not equally indicated for all antipsychotics and not planned as a way of providing insight if there are no questions. In other words, it is a problem-solving tool for a problem, a complicated situation, or a challenging scenario you’re trying to solve,” Dr. Schoretsanitis said.
The authors divided their recommendations regarding routine TDM for antipsychotics into four categories, based on level of evidence:
Strongly recommended (Level 1)
- Clozapine
- Fluphenazine
- Haloperidol
- Olanzapine
- Perazine
- Perphenazine
Recommended (Level 2)
- Aripiprazole
- Chlorpromazine
- Flupentixol
- Paliperidone
- Quetiapine
- Risperidone
- Sertindole
- Ziprasidone
Useful (Level 3)
- Brexpiprazole
- Cariprazine
- Chlorprothixene
- Iloperidone
- Loxapine
- Lurasidone
- Melperone
- Pimozide
Potentially useful (Level 4)
- Asenapine