No Addiction Medicine Service? No Problem! Things You Need to Know to Care for Patients with Substance Use Disorders

Hospitalists frequently encounter patients with substance use disorders (SUDs), yet many institutions lack dedicated addiction medicine services. As opioid-related hospitalizations and overdose deaths continue to surge in the U.S., the role of hospitalists in initiating treatment for opioid use disorder (OUD) has never been more urgent. This session, led by Anna-Maria South, MD, FACP, FASAM, assistant professor in the addiction consult and education service at the University of Kentucky College of Medicine in Lexington, Ky., and Keri Holmes-Maybank, MD, MSCR, SFHM, associate professor in the complex pain clinic, Rena Grant Sickle Cell Medical Home, at the Medical University of South Carolina in Charleston, S.C., provided practical strategies for hospitalists to manage OUD and alcohol use disorder (AUD) effectively. The session emphasized different strategies to initiate buprenorphine, naltrexone, acamprosate, gabapentin, and phenobarbital therapy in patients with SUDs.

The session opened by highlighting the mortality benefits of initiating medication for opioid use disorder (MOUD). Dr. South emphasized that MOUD is associated with reduced rehospitalizations, emergency visits, and infection recurrences, along with improved treatment adherence and abstinence from illicit drug use.^1,2 Buprenorphine, a partial mu-opioid receptor agonist and kappa antagonist, has high receptor affinity and a ceiling effect on respiratory depression and carries low toxicity and abuse potential. Buprenorphine initiation for OUD can occur in two settings: with or without opioid withdrawal.^3,4 For patients in moderate withdrawal (Clinical Opioid Withdrawal Scale [COWS] of at least 8), traditional induction is appropriate.

Initiation timing depends on the last opioid used:

• Short-acting opioids: wait at least 12 hours
• Long-acting opioids: wait at least 24 hours
• Methadone: wait more than 24 hours

Traditional induction protocol:

• Day 1: Start with 4 mg sublingual; if withdrawal persists after one hour, give 4 mg every two to four hours as needed, up to 16 mg/day
• Day 2: Begin with the total Day 1 dose, with 4 mg as needed (PRN) every two to four hours, maximum 16 mg/day
• Day 3 onward: Use the total Day 2 dose as baseline, with PRN doses as above, up to 24 mg/day

For patients not in opioid withdrawal (COWS less than 2) and who have not received opioids in the past five days, buprenorphine can be safely initiated as:

• Day 1: Start with 2 mg sublingual. If no sedation or precipitated withdrawal occurs, give 2 mg every six hours as needed for cravings, up to 8 mg/day.
• Day 2: Begin with the total Day 1 dose, with 2 mg every six hours PRN, maximum 16 mg/day.
• Day 3 onward: Use the total Day 2 dose as baseline, with PRN doses up to 24 mg/day.

Dr. South introduced low-dose buprenorphine initiation or microdosing as a strategy to prevent precipitated withdrawal and avoid the need for traditional induction withdrawal.^4,5 This approach is ideal for hospitalized patients with uncontrolled pain who are on full opioid agonists, including those using high-dose opioids, chronic illicit fentanyl, or methadone at more than 40 mg/day. It is also suitable for patients unwilling to discontinue opioids for standard induction.  Microdosing follows a three or seven-day protocol, with gradual daily up-titration. It may begin with sublingual only, buccal, or transdermal forms, transitioning to sublingual dosing.

Hospitalists are encouraged to initiate buprenorphine-naloxone during hospitalization and ensure patients are connected with outpatient providers for continued care upon discharge.³ To avoid treatment gaps, prescribe a sufficient supply to bridge until follow-up. Naloxone should be provided at discharge to all patients with OUD or overdose risk. As of 2023, the X-waiver is no longer required; any clinician with a Schedule II Drug Enforcement Agency license can prescribe buprenorphine. This change empowers hospitalists to deliver evidence-based, life-saving treatment and engage patients in recovery at a crucial moment.

A key aspect of MOUD is recognizing and managing buprenorphine-precipitated withdrawal, indicated by a sharp increase in COWS after dosing.^4,5 Treat by addressing the opioid deficit: administer 4 to 8 mg buprenorphine hourly until COWS drops below 8. If buprenorphine is declined, discontinue it and initiate a full opioid agonist (e.g., morphine or methadone), with close respiratory monitoring. Use adjunct medications such as clonidine, NSAIDs, antiemetics, and antidiarrheals for symptom control. For patients on home buprenorphine regimens admitted with acute pain, continue buprenorphine and manage pain with non-opioid therapies first, adding short-acting opioids at a higher dose if needed.

The session continued with a discussion on emerging challenges from substances such as fentanyl, xylazine, and medetomidine. Fentanyl is about 100 times more potent than morphine and has become a common adulterant in illicit drugs, contributing to a 282% rise in overdose deaths between 2016 and 2021. Management includes low-dose buprenorphine initiation and full opioid agonists for acute pain. Due to its rapid onset and prolonged duration, multiple doses of naloxone may be needed for reversal. Xylazine and medetomidine, veterinary α₂-adrenergic agonists, increasingly contaminate street opioids and contribute to overdose deaths. These agents are undetectable by routine urine screens or autopsy toxicology screens, further underestimating their prevalence.

Dr. South discusses harm reduction strategies for hospitalized patients with opioid use disorder, minimizing risks while providing compassionate care and empowering patients with an addiction recovery management framework. Upon discharge, clinicians should prescribe naloxone and connect patients with outpatient MOUD providers.

Dr. Holmes-Maybank shifted focus to AUD.^6,7 More than 178,000 deaths between 2020-2021 were linked to excessive alcohol use. The AUDIT-C screening tool helps identify patients with AUD (score at least 8, 92% specificity). Medications for AUD (MAUD) improve abstinence, mortality, rehospitalization, and emergency department visits:

• Naltrexone: First-line; start at 25 mg/day, increase to 50 mg/day (maximum 150 mg/day). Patients must be opioid-free for seven to 10 days. Avoid in severe liver disease (Child-Pugh C).
• Acamprosate: Preferred in severe liver disease (Child-Pugh C); start 666 mg three times daily after five to 10 days of abstinence (reduce to twice daily if patient weighs less than 60 kg). Avoid if creatinine clearance is less than 30 mL/min.
• Disulfiram: Reduces drinking frequency; begin 250 mg daily after 48 hours of abstinence (maximum 500 mg/day); limited by side effects and interactions.
• Gabapentin: Start at 600 mg three times daily; improves abstinence and sleep, though not U.S. Department of Food and Drug Administration-approved for AUD.

The session concluded with the role of phenobarbital in acute alcohol withdrawal. Though benzodiazepines remain first-line, phenobarbital is effective in resistant or challenging withdrawals. It is non-inferior to benzodiazepines and can be used as an alternative:

• Load with 10 mg/kg divided into three doses
• Maintenance: 65 mg every six to eight hours, scheduled or PRN
• Gabapentin may be used alongside benzodiazepines and continued post-discharge with tapering

This session underscored that hospitalists are uniquely positioned to address SUDs during hospitalization. By adopting evidence-based practices for initiating MOUD and MAUD, clinicians can improve outcomes and reduce mortality.^3,7 The presenters emphasized collaboration, shared decision-making, and leveraging hospitalization as a pivotal intervention point.³ Equipping hospitalists with these tools ensures patients receive life-saving care, regardless of institutional resources.

Hospitalists are uniquely positioned to initiate MOUD and MAUD, offering life-saving interventions during hospitalization. This session highlighted the importance of evidence-based practices, harm reduction, and shared decision-making. As emphasized by the presenters, “Every quit attempt counts.” Empowering hospitalists with these tools can transform care for patients with SUD regardless of institutional resources.

Dr. Talari is an internal medicine hospitalist at AdventHealth DeLand in DeLand, Fla., and an assistant professor at Florida State University College of Medicine in Daytona Beach, Fla.

References

1. Evans E, et al. Mortality among individuals accessing pharmacological treatment for opioid dependence in California, 2006-10. Addiction. 2015;110(6):996-1005. doi:10.1111/add.12863
2. Sordo L, et al. Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies. BMJ. 2017;357:j1550. doi:10.1136/bmj.j1550
3. Calcaterra SL, et al. Management of opioid use disorder and associated conditions among hospitalized adults: a consensus statement from the Society of Hospital Medicine. J Hosp Med. 2022;17(9):744-756. doi:10.1002/jhm.12893
4. Ghosh SM, et al. A review of novel methods to support the transition from methadone and other full agonist opioids to buprenorphine/naloxone sublingual in both community and acute care settings. Canadian J Addict. 2019;10(4):41–50. doi:10.1097/CXA.0000000000000072
5. Oakley B, et al. Managing opioid withdrawal precipitated by buprenorphine with buprenorphine. Drug Alcohol Rev. 2021;40(4):567-571. doi:10.1111/dar.13228
6. Kee DP, et al. Things we do for no reason™: avoiding naltrexone for alcohol use disorder in liver disease. Journal of Hospital Medicine website. https://shmpublications.onlinelibrary.wiley.com/doi/abs/10.1002/jhm.13569. Published December 10, 2024. Accessed May 24, 2025. doi:10.1002/jhm.13569
7. Public Health Institute. Resources. Bridge website. https://bridgetotreatment.org/tools/resources/. Published 2025. Accessed May 24, 2025.