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.

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