Psychiatrists' Perspectives on Antipsychotic Dose and the Role of Plasma Concentration Therapeutic Drug Monitoring

Abstract

Current prescribing decisions regarding antipsychotic dose are mainly influenced by clinician intuition, previous experience, and patient preference. Although some expressed concerns regarding the evidence base, most clinicians reported that they would use TDM for antipsychotics if readily available.

Olanzapine and risperidone plasma concentration therapeutic drug monitoring: A feasibility study

“…Hence, given the current state of knowledge, uptake of TDM is likely to be slow were it to become widely available. In light of the feasibility shown here and general positive attitudes (Best-Shaw et al, 2014), it is also likely that less invasive measures and the targeting of specific patients (who might be more likely to benefit) would facilitate uptake of TDM in many inpatient units. …”

“…The lack of dose decrease may be due to the TDM results rarely supporting a dose reduction; indeed, the majority of results indicated either partial adherence or for the current dose to be maintained or increased until a minimum effective dose was reached (Hiemke et al, 2011). However, few clinicians confirmed that they had checked the TDM results, even though most results were reported within 4 days, which was considered to be an appropriate time frame (Best-Shaw et al, 2014). Clinicians may have been inadvertently unaware that the results were available.…”

“…Currently, clozapine is the only SGA for which TDM is more routinely used in clinical practice in the UK, despite psychiatrists holding mainly positive attitudes to TDM for other SGAs (Best-Shaw et al, 2014;Conca et al, 2011;Patel et al, 2014b). This may be a result of weak evidence that TDM can improve clinical outcomes for other SGAs as compared with clozapine (Lopez and Kane, 2013).…”

Optimizing Antipsychotic Patient Management Using Population Pharmacokinetic Models and Point‐of‐Care Testing

“…Another significant cause of this variability is a lack of or inconsistent adherence to prescribed medication, leading to variable clinical responses, or a higher frequency of adverse events. With only 29–45% of APS concentrations within a consistent concentration range, therapeutic drug monitoring (TDM) has been recommended for clozapine, olanzapine, amisulpride, aripiprazole, paliperidone, quetiapine, risperidone, sertindole, and ziprasidone …”

Personalizing Antipsychotic Treatment of Schizophrenia: Monitoring Plasma Levels for Improved Treatment Decisions

“…In two studies from the United Kingdom, eight out of ten psychiatrists surveyed stated that plasma monitoring would help "minimize the risk of toxicity." 68,69 Plasma levels may be particularly useful for antipsychotics with dose-dependent risks-especially clozapine, given the drug's risk for seizures above a certain plasma level.…”