ABSTRACT
More than half a million patients receive treatment at opioid treatment programs (OTPs) around the country, 95%
of whom receive methadone as a medication for opioid use disorder (OUD), which is the gold standard for
treating OUD. Current clinical practice for methadone medication treatment of OUD follows long-established
federal and state regulatory policies that are highly restrictive and require patients to present in-person to a
registered OTP every day to receive their prescribed methadone dose, creating an enormous obstacle to
treatment that disproportionately impacts rural populations and low-income communities where lack of clinics,
limited transportation, and/or inflexible jobs can make daily appointments difficult to sustain. This compliance
burden contributes to program drop-out rates and adds to the public stigma surrounding OUD. States, OTPs,
and other stakeholders have reported that a relaxation of federal policy during the COVID-19 pandemic, which
allowed OTPs to prescribe longer take-home doses of medication to stable patients, had positive impact,
resulting in increased treatment engagement, improved patient satisfaction with care, and few incidents of
medication misuse. As a result, the U.S. Substance Abuse and Mental Health Services Administration
(SAMHSA) has proposed making the changes permanent. However, many care providers remain reluctant to
prescribe the full amount of allowable take-home doses due, in part, to ingrained stigmas and fears regarding
overdoses and diversion of medication.
To help overcome provider reluctance and increase confidence in take-home medication compliance,
this Fast-Track project proposes the development of an unobtrusive wearable biosensor device capable of
detecting and remotely monitoring a patient’s taken doses of methadone to enable trustworthy take-home
methadone treatment options that can expand access to OUD healthcare. The core of CARI Health’s remote
medication monitoring (RMM) system is an electrochemical sensor that can detect and quantitate methadone
and its metabolite EDDP in human interstitial fluid (ISF) using differential pulse voltammetry and a custom
microneedle array. To date, CARI has successfully created and tested prototypes of the proposed sensor,
microneedle array, and assay. This project proposes to integrate these components into a prototype device and
develop an accompanying device data pipeline in Phase I (Aims 1-3), then develop a commercial grade product
(Aim 4), at-scale manufacturing processes (Aim 5), and clear the CARI RMM for human wearable use (Aim 6)
during Phase II to prepare for testing the CARI RMM in clinical studies (Aims 7, 8)
It is expected that successful achievement of the above aims will facilitate FDA clearance of a de novo
class II device and begin the commercialization process of the CARI Health monitoring system, a timely
innovation that will help maximize the impact of SAMHSA’s efforts to update regulatory policies to meet the
recognized needs of OUD patients.