Adherence is one of the pivotal determinants of treatment outcomes for many medical disorders. It is estimated that 50% or more of patients with chronic conditions are noncompliant with medications at some time during their illness. Although there have been numerous attempts to develop approaches to evaluate adherence to drug therapy, including electronic dosing monitors, quantitative assessment of adherence remains a formidable challenge. Quantification of adherence to drug administration requires an adequate understanding of the dose versus plasma concentration relationships. Prior methods to evaluate adherence to drug therapy simply used plasma blood levels of medications in a qualitative manner to judge whether a patient had consumed any amount of medication. This does not allow conclusions to be made about the degree of adherence.
University of California Researchers propose that a biomarker-guided evaluation of adherence to antipsychotic therapy can be formalized, from a quantitative standpoint, by developing a nomogram that incorporates the pertinent biomarker data on key drug metabolism and transport pathways as well as the relevant clinical or demographic variables. They are developing a multivariate predictive model to measure adherence, guided by biomarkers of an intestinal transport protein activity in intestinal luminal surface and hepatic metabolism. This invention is envisioned as a clinical product that can be used to quantify the degree of adherence to antipsychotic treatment at point of patient care. To our knowledge, it has never been proposed to use biomarkers to develop a quantitative algorithm or nomogram to measure a patient's medication adherence. Traditionally, biomarkers of drug metabolism, pharmacokinetics or drug targets have been used to predict a patient's response (efficacy or toxicity) to a medication - but not to formally quantify medication adherence per se. Hence, the described invention is novel as it creates a new process and application of biomarkers directly relating to the degree of adherence to drug therapy.
This methodology will allow for the quantitative assessment of adherence through the incorporation of not only oral dose of medication and plasma medication levels, but also key biomarkers that significantly impact the drugs absorption, metabolism, transport, distribution or excretion.