Antagonist Rx Rx Adjustments Setting Notes
Naltrexone should
not be initiated
May be
discontinued if risk
of relapse is low
Continue only with
consent
Dose increase as
pregnancy advances
Level 4 for
methadone
induction and
buprenorphine Rx
Encourage breast
feeding
Naltrexone
XR or oral
Mild: NSAIDs or
acetaminophen
Moderate: Increase
agonist or add
opioid
Severe: Discontinue
buprenorphine;
add a high potency
opioid (fentanyl)
All Discontinue oral
naltrexone 72 hrs
(or 30 days for
extended-release)
before surgery
Naltrexone
XR or oral
N/A All Legal requirements
and FDA approvals
for under age 18
Naltrexone
XR or oral
Manage drug
interactions
Consider Levels 1
or 2 for coincident
schizophrenia
Naltrexone
XR
Prison or parolee
Levels 1–4
Initiate Rx ≥30
days before release
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