# 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

![Multimodal analgesia pyramid showing non-opioid foundations with opioids reserved for top-tier use](/images/residency/multimodal-analgesia-pyramid.jpg)

## 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

| Opioid | IV Dose | PO Dose | Notes |
|--------|---------|---------|-------|
| Morphine | 10 mg | 30 mg | Reference standard; avoid in CKD |
| Hydromorphone | 1.5 mg | 7.5 mg | Preferred in renal insufficiency |
| Oxycodone | N/A | 20 mg | PO only; IR and ER formulations |
| Fentanyl | 100 mcg | N/A (transdermal) | No active metabolites; safe in renal failure |
| Hydrocodone | N/A | 30 mg | PO only; combination products |

- 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

![Checklist for safe opioid prescribing in opioid-naive hospitalized patients](/images/residency/safe-opioid-prescribing-checklist.jpg)

## 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)

![Algorithm for discharge opioid prescribing with quantity limits and safety counseling](/images/residency/discharge-opioid-algorithm.jpg)

## 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.