Residency · Residency · Internal Medicine

Opioid Management in the Hospitalized Patient

Introduction

Opioids are essential analgesics in the inpatient setting for moderate-to-severe acute pain, postoperative pain, and pain in serious illness. However, inappropriate prescribing contributes to adverse events including respiratory depression, delirium, falls, ileus, and the risk of long-term opioid use disorder. The internist must balance effective pain control with safe prescribing practices, using multimodal analgesia and evidence-based principles.

Principles of Inpatient Pain Management

Pain Assessment

• Use validated pain scales: Numeric Rating Scale (NRS 0-10), Wong-Baker FACES, or behavioral scales for non-verbal patients (CPOT, BPS)
• Assess pain at rest and with activity; functional goals matter more than a pain score of zero
• Identify pain type: nociceptive (somatic, visceral) vs. neuropathic; mixed pain is common
• Evaluate prior opioid exposure, current home medications, and history of substance use disorder
• Set realistic pain expectations: aim for functional improvement, not complete pain elimination

Multimodal Analgesia (Opioid-Sparing Approach)

• Acetaminophen: scheduled dosing (650-1000 mg every 6-8 hours); ceiling dose 3-4 g/day (2 g/day in liver disease)
• NSAIDs: effective for musculoskeletal and inflammatory pain; avoid in renal insufficiency, heart failure, GI bleeding risk
• Gabapentinoids: gabapentin or pregabalin for neuropathic pain; reduce opioid requirements; dose-adjust for renal function
• Muscle relaxants: cyclobenzaprine, methocarbamol for musculoskeletal spasm; avoid in elderly
• Topical agents: lidocaine patches, diclofenac gel for localized pain
• Regional anesthesia: nerve blocks, epidurals; consult anesthesiology for postoperative and trauma patients
• Non-pharmacologic: ice, heat, positioning, physical therapy, relaxation techniques

Opioid Pharmacology Essentials

Commonly Used Inpatient Opioids

• Morphine: gold standard; renally cleared (active metabolites accumulate in CKD); avoid in GFR < 30
• Hydromorphone (Dilaudid): 5-7x more potent than morphine; preferred in renal insufficiency
• Oxycodone: oral agent; moderate potency; available in immediate and extended-release formulations
• Fentanyl: highly lipophilic; rapid onset IV; useful in renal failure (no active metabolites)
• Tramadol: weak opioid; serotonergic properties; lowers seizure threshold; avoid with SSRIs/SNRIs
• Meperidine: avoid entirely; neurotoxic metabolite (normeperidine) causes seizures

Equianalgesic Dosing

• Use equianalgesic tables when converting between opioids
• Apply a dose reduction of 25-50% when rotating to a new opioid (incomplete cross-tolerance)
• Morphine equivalents: hydromorphone 1.5 mg IV = morphine 10 mg IV; oxycodone 20 mg PO = morphine 30 mg PO
• Calculate morphine milligram equivalents (MME) to quantify total opioid burden

Routes of Administration

• IV: fastest onset (5-10 min); use for severe acute pain; titrate to effect
• PO: preferred when patient is tolerating oral intake; onset 30-60 minutes
• Patient-controlled analgesia (PCA): allows patient-driven boluses with lockout intervals; useful postoperatively
• Avoid IM injections (unpredictable absorption, painful)

Safe Opioid Prescribing in the Hospital

Initiating Opioids

• Start with the lowest effective dose in opioid-naive patients
• Opioid-naive: morphine 2-4 mg IV every 3-4 hours PRN, or oxycodone 5 mg PO every 4-6 hours PRN
• Reassess pain and sedation within 1 hour of IV dose, 2 hours of PO dose
• Titrate based on response; increase by 25-50% if inadequate relief

Monitoring

• Sedation scale (Pasero Opioid-Induced Sedation Scale) is the best early indicator of impending respiratory depression
• Monitor respiratory rate, oxygen saturation, and level of consciousness
• Capnography (end-tidal CO2 monitoring) in high-risk patients on PCA
• High-risk patients: obstructive sleep apnea, obesity, elderly, concurrent sedatives, opioid-naive receiving high doses

Avoiding Common Errors

• Do not co-prescribe opioids with benzodiazepines unless absolutely necessary
• Hold or reduce opioids if sedation score is elevated, even if pain score is high
• Prevent opioid-induced constipation: start bowel regimen (senna + docusate or PEG) with every opioid order
• Do not use long-acting opioids in opioid-naive patients
• Avoid ordering opioids as "standing" doses in opioid-naive patients; use PRN with reassessment

Managing Patients on Chronic Opioid Therapy

• Continue home opioid regimen to prevent withdrawal (unless indication for change)
• Verify the home medication list with the patient and pharmacy; check the Prescription Drug Monitoring Program (PDMP)
• Treat acute pain with short-acting opioids in addition to baseline regimen
• Consider non-opioid adjuncts to minimize dose escalation
• If opioid use disorder is suspected, consult addiction medicine; consider buprenorphine

Opioid Use Disorder in the Hospital

• Screen for opioid use disorder using DSM-5 criteria
• Buprenorphine can be initiated in the hospital for opioid use disorder; internists should be comfortable starting it
• X-waiver requirement has been eliminated; any licensed prescriber can prescribe buprenorphine
• Induction protocols: start when patient is in mild-moderate withdrawal (COWS score >= 8)
• Connect patients with outpatient addiction treatment before discharge

Discharge Opioid Prescribing

• Prescribe the minimum quantity needed (typically 3-5 days for acute pain)
• Educate patients on safe storage and disposal of unused opioids
• Do not prescribe long-acting opioids at discharge for acute pain
• Ensure a follow-up plan for pain reassessment
• Prescribe naloxone for patients at high risk of overdose (concurrent benzodiazepines, high MME, history of overdose)

Key Clinical Pearls

• Multimodal analgesia is the foundation of pain management; opioids should supplement, not replace, non-opioid agents
• Sedation precedes respiratory depression; monitor sedation scores, not just respiratory rate
• Always start a bowel regimen when prescribing opioids; constipation is universal and does not develop tolerance
• Any clinician can now prescribe buprenorphine for opioid use disorder; use hospitalization as an opportunity to initiate treatment
• Prescribe the minimum opioid quantity at discharge with a clear follow-up plan

References

1. Dowell D, Ragan KR, Jones CM, Baldwin GT, Chou R. CDC clinical practice guideline for prescribing opioids for pain, 2022. MMWR Recomm Rep. 2022;71(3):1-95.
2. Chou R, Gordon DB, de Leon-Casasola OA, et al. Management of postoperative pain: a clinical practice guideline from the APS, ASRA, and ASA. J Pain. 2016;17(2):131-157.
3. Herzig SJ, Mosher HJ, Calcaterra SL, Jena AB, Nuckols TK. Improving the safety of opioid use for acute noncancer pain in hospitalized adults. J Hosp Med. 2018;13(4):263-271.
4. Liebschutz JM, Crooks D, Herman D, et al. Buprenorphine treatment for hospitalized, opioid-dependent patients: a randomized clinical trial. JAMA Intern Med. 2014;174(8):1369-1376.

For the intern

At 3am, when you're paged for pain, quickly assess severity, vital signs, and sedation level. For moderate-to-severe pain in an opioid-naive patient, give morphine 2-4 mg IV or oxycodone 5 mg PO, recheck in 1-2 hours, and ensure scheduled acetaminophen is ordered. If the patient is on home opioids, verify they received their baseline dose and add short-acting PRN for breakthrough pain. Never give opioids if the patient is overly sedated. Check that a bowel regimen is ordered—this can wait until morning rounds but is frequently forgotten. What can wait: switching opioid formulations, converting to long-acting agents, consulting pain service, or calculating exact morphine milligram equivalents for documentation.

Common pitfalls

• Forgetting the bowel regimen: Constipation is universal with opioids and doesn't improve with tolerance. Start senna plus docusate or polyethylene glycol with the first opioid dose, not after the patient complains.

• Ignoring sedation scores: Sedation precedes respiratory depression. If your patient is difficult to arouse, hold opioids even if they report high pain scores—reassess with non-opioid alternatives first.

• Underdosing chronic opioid users: Patients on home opioids need their baseline regimen continued plus additional short-acting opioids for acute pain. Verify home doses with the pharmacy and PDMP.

• Co-prescribing benzodiazepines: This combination dramatically increases respiratory depression risk. If both are necessary, increase monitoring and consider ICU-level care for high-risk patients.

Make it stick

It’s 2 AM, and Mr. Henderson, 72, 3 days post-op for a bowel resection, is groaning. His nurse pages you: “Pain 9/10, respirations 10, drowsy but arousable.” You rush to the room. He’s slumped, barely responding, but insists his pain is severe. Your first instinct might be to order more pain medication. Instead, you check his electronic health record: he received hydromorphone two hours ago and has scheduled gabapentin and acetaminophen. You notice his oxygen saturation is dipping. You pause, hold the PRN opioid, sit him up, encourage deep breaths, and give him 2 mg of IV naloxone per protocol. His mental status improves within minutes. He’s still in pain, but now you can safely reassess and consider non-opioid adjuncts or a lower opioid dose.

If you remember one thing

Sedation always precedes respiratory depression; prioritize patient safety over chasing a pain score. Always ensure a bowel regimen is active when opioids are on board.

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