The Bridge Device (BD) is a neuromodulator medical device that has been cleared by the FDA
for Opioid Use Disorder (OUD) treatment. Importantly, medical devices reviewed by the FDA are
cleared (based on safety) rather than approved (based on efficacy), which means the BD did
not need to demonstrate efficacy before it became commercially available. As a result, the
device was not required to have a sham-controlled trial for FDA clearance and there is no
active research, to the investigators' knowledge, that specifically addresses the degree to
which opioid withdrawal can be treated through neuromodulation. To rigorously evaluate the
efficacy of the BD for treating OUD, the investigators will enroll persons with active OUD,
not currently receiving medications for OUD. Participants will be recruited and admitted to
the Clinical Research Unit (CRU) for a 2-3 week period. During participants' residential
stay, participants will be stabilized for 7-11 days on four times daily morphine (30 mg, SC)
and undergo a precipitated withdrawal challenge using the opioid antagonist naloxone,
approximately >= 4 days of morphine maintenance. This is a standard practice for the
investigators' study and allows the investigators to objectively assess dependence. The BD
and study medication will begin following morphine stabilization. Participants will be
randomly assigned to one of three conditions (1) active BD with placebo (BD/P), (2) sham BD
with lofexidine (SBD/L), or (3) sham BD and placebo (SBD/P). Participants will use the BD for
5 days and will receive study drug for 7 days. Participants will be monitored for an
additional 4 days after device removal to determine whether withdrawal resumes. Participants
will undergo a second naloxone challenge after removal of the device/capsule completion to
verify lack of opioid tolerance and will be encouraged to begin treatment with oral
naltrexone followed by extended release naltrexone. Throughout the residential stay, all
participants will be given referral to and assisted with engaging in outpatient treatment
following study discharge.