Key Takeaways
- Respiratory depression is the most serious opioid adverse effect - assess respiratory rate before EVERY dose; hold if RR < 12/min
- Naloxone (Narcan) is the antidote for opioid overdose - it has a shorter half-life than most opioids, so re-sedation can occur
- Opioid-naive patients are at highest risk for respiratory depression - start low and titrate slowly
- Constipation is an expected side effect that does NOT develop tolerance - prophylactic bowel regimen is essential
- Assess pain using validated scales; do not rely solely on vital signs or patient appearance
High-Alert Medications: Opioids
Opioid analgesics are essential for pain management but carry significant risks. The NCLEX tests your ability to safely administer opioids, recognize adverse effects, and respond to emergencies.
Common Opioid Analgesics
| Drug | Route | Relative Potency | Duration |
|---|---|---|---|
| Morphine | PO, IV, IM, SubQ | Standard (1x) | 4-5 hours |
| Hydromorphone (Dilaudid) | PO, IV | 5-7x morphine | 4-5 hours |
| Fentanyl | IV, Transdermal, Transmucosal | 80-100x morphine | IV: 30-60 min; Patch: 72 hr |
| Oxycodone | PO | 1.5x morphine | 4-6 hours |
| Hydrocodone | PO | ~1x morphine | 4-6 hours |
| Codeine | PO | 0.1x morphine | 4-6 hours |
| Meperidine (Demerol) | PO, IM | 0.1x morphine | 2-3 hours |
Clinical Note: Meperidine is rarely used due to neurotoxic metabolite (normeperidine) that can cause seizures.
Before Administration: The Opioid Assessment
ALWAYS assess before each dose:
- Respiratory Rate - Hold if < 12 breaths/min
- Level of Consciousness - Excessive sedation = hold and assess
- Pain Score - Document current pain level
- Last Dose Time - Verify minimum interval has passed
- Allergies - True allergy vs. expected side effect
- Other CNS Depressants - Benzodiazepines, alcohol increase risk
Respiratory Depression: The Priority Concern
Signs of Opioid-Induced Respiratory Depression:
- Respiratory rate < 12/min
- Shallow respirations
- Oxygen saturation declining
- Excessive sedation (difficult to arouse)
- Snoring or obstructed breathing
Sedation Scale (Pasero Opioid-Induced Sedation Scale):
| Level | Description | Action |
|---|---|---|
| S = Sleep | Normal sleep, easily aroused | None |
| 1 | Awake and alert | None |
| 2 | Slightly drowsy, easily aroused | Acceptable |
| 3 | Frequently drowsy, arousable | Decrease dose; monitor closely |
| 4 | Somnolent, minimal response | Stop opioid; call provider; consider Naloxone |
Naloxone (Narcan): Opioid Reversal
Indications:
- Respiratory depression (RR < 8-10/min)
- Unresponsive to stimulation
- Oxygen saturation falling despite supplemental O2
Administration:
- IV: 0.4-2 mg every 2-3 minutes until response
- IM, SubQ, or Intranasal if no IV access
- Titrate to respiratory improvement, NOT complete reversal
Critical Concept: Naloxone has a shorter half-life (30-90 min) than most opioids (4-5 hours). Re-sedation can occur. Monitor for at least 2 hours after administration; may need repeat doses.
Side Effects of Rapid Reversal:
- Severe pain return
- Hypertension, tachycardia
- Pulmonary edema
- Withdrawal symptoms in opioid-dependent patients
Managing Opioid Side Effects
| Side Effect | Management |
|---|---|
| Constipation | Prophylactic stool softener + stimulant laxative (does NOT develop tolerance) |
| Nausea/Vomiting | Antiemetics; usually improves after 2-3 days |
| Pruritus (itching) | Antihistamines; not a true allergy |
| Urinary retention | Bladder assessment; may need catheterization |
| Hypotension | Slow position changes; assess fluid status |
| Sedation | Expected initially; assess for excessive sedation |
Opioid-Naive vs. Opioid-Tolerant
| Opioid-Naive | Opioid-Tolerant |
|---|---|
| No recent opioid use | Regular opioid use > 1 week |
| Higher risk of respiratory depression | May need higher doses for effect |
| Start with lower doses | Cross-tolerance to other opioids |
| Titrate slowly | Still at risk if doses increased |
Equianalgesic Dosing
When converting between opioids, use equianalgesic charts:
| Opioid | Oral Dose | IV Dose |
|---|---|---|
| Morphine | 30 mg | 10 mg |
| Hydromorphone | 6 mg | 1.5 mg |
| Oxycodone | 20 mg | N/A |
Remember: These are approximations. Incomplete cross-tolerance means starting 25-50% below calculated dose.
Patient-Controlled Analgesia (PCA)
Safety Features:
- Lockout interval prevents overdose
- Basal rate (if ordered) provides continuous relief
- Patient activates demand doses
- Only the PATIENT should push the button (not family)
Nursing Responsibilities:
- Verify pump settings with two nurses
- Assess pain and sedation regularly
- Document usage and pain scores
- Teach patient proper use
Special Populations
Elderly:
- Start at 25-50% of usual adult dose
- Longer duration of action (slower metabolism)
- Higher risk of falls, confusion
Renal Impairment:
- Morphine metabolites accumulate - consider alternatives
- Hydromorphone or fentanyl often preferred
Hepatic Impairment:
- Reduced metabolism - lower doses needed
- Extended duration of action
On the Exam
- Respiratory assessment before every opioid dose
- Know when to hold medication (RR < 12)
- Recognize need for Naloxone
- Understand that constipation requires prophylaxis
- PCA - only patient pushes button
A patient receiving IV morphine has a respiratory rate of 8/min, is difficult to arouse, and has oxygen saturation of 88%. The nurse's priority action is:
After administering Naloxone for opioid overdose, the nurse should:
Which opioid side effect does NOT develop tolerance over time?
A patient with a PCA pump appears over-sedated. The family member states, "I've been pushing the button for him so he can rest." The nurse should: