Published online by Cambridge University Press: 19 October 2021
The use of antipsychotics to treat schizophrenia is fraught with many layers of complexity as prescribers try to tailor the pharmacodynamic properties of an agent to a specific patient based primarily on subjective response. Variations in drug metabolism related to genetic polymorphisms, or to medication or environmental exposures (e.g. smoking), and variable adherence with oral medications lead to scenarios that confound even seasoned clinicians. Excluding the realization that up to one-third of schizophrenia patients may not respond adequately to non-clozapine antipsychotics, 60 years of antipsychotic research has demonstrated that dose is a poor correlate of response likelihood, whereas plasma drug levels represent the best clinically available tool that quantifies the relationship between drug exposure and central nervous system (CNS) activity .