1. Introduction
Palliative care prioritizes relief from distressing symptoms—particularly pain—to enhance the quality of life for patients with life-limiting illnesses. Morphine remains the gold standard strong opioid for moderate to severe pain. Effective morphine prescribing in palliative care involves:
Background (regular) dosing for continuous pain control
Breakthrough (PRN) dosing for sudden flares
Systematic dose adjustments based on patient response and PRN usage
2. Comprehensive Pain Assessment
A thorough assessment underpins effective morphine use:
Pain Character: Aching, burning, stabbing, etc.
Severity: Use a pain scale (0–10 or mild/moderate/severe).
Pattern: Persistent vs. episodic flares.
Functional Impact: Daily activities, sleep, mood.
Holistic evaluation of psychological, social, and spiritual factors is also vital.
3. Setting Up Morphine Background Orders
When initiating or adjusting morphine for persistent pain, two key strategies help refine the dose:
3.1 Start Low, Go Slow
Initial Dose: In opioid-naïve patients, begin with a low oral morphine dose (e.g., 5–10 mg every 4 hours) or use a 12-hourly extended-release formulation at a comparable total daily dose.
This cautious approach reduces the risk of opioid-related side effects (e.g., sedation, respiratory depression).
3.2 Titration (Method 1)
Assess Pain and Side Effects: After 24–48 hours on a stable morphine regimen.
Dose Increase: If pain remains uncontrolled, increase the total daily dose by 25–50%.
Example: If a patient is on 60 mg/day and still has moderate to severe pain, increase to ~75–90 mg/day.
Monitor: Re-evaluate pain scores, sedation level, and any adverse effects.
3.3 Next-Day Dose Adjustment Using PRN Doses (Method 2)
Track PRN Usage: Each time the patient takes a breakthrough (PRN) morphine dose, record it.
Add PRN Total to Background: The total PRN amount taken in 24 hours can be added to the next day’s background dose.
Example:
Day 1 Background Dose = 60 mg/24h
Day 1 PRN Usage = 20 mg total
New Background Dose (Day 2) = 60 mg + 20 mg = 80 mg/24h
This approach matches real-life opioid requirements more closely by using the actual extra doses needed.
4. Regular (Around-the-Clock) Dosing
Continuous Pain Relief: Around-the-clock morphine ensures that persistent baseline pain is consistently managed.
Long-Acting/Extended-Release Preparations: Can be given every 12 hours (e.g., morphine sulfate SR) or every 24 hours, depending on product formulation and patient tolerance.
5. Breakthrough Pain (BTP) Management
Breakthrough pain is a sudden, severe pain flare that occurs despite regular morphine coverage.
Immediate-Release Morphine (PRN): Commonly 10–20% of the total 24-hour morphine background dose.
Example: If the patient’s total daily dose is 60 mg, the PRN dose is ~6–12 mg every 30–60 minutes as needed.
Reassess: If breakthrough doses are used frequently (e.g., more than 3–4 times in 24 hours), increase the background dose (using either Method 1 or Method 2 from above).
6. WHO Analgesic Ladder & Adjuncts
WHO Analgesic Ladder:
Step 1: Non-opioids (paracetamol, NSAIDs).
Step 2: Weak opioids (codeine, tramadol).
Step 3: Strong opioids (morphine, fentanyl, oxycodone).
Adjuvant therapies (e.g., antidepressants, anticonvulsants, corticosteroids) may be added at any step to address neuropathic or inflammatory pain.
7. Common Opioid Conversions
Conversion | Ratio | Example |
Codeine → Morphine (oral) | 10 : 1 | 240 mg codeine = 24 mg morphine (24 h) |
Tramadol → Morphine (oral) | 5 : 1 | 400 mg tramadol = 80 mg morphine (24 h) |
Morphine (oral) → Morphine (SC/IV) | 3 : 1 | 30 mg oral = 10 mg SC/IV (24 h) |
Morphine (oral) → Fentanyl (TD) | ~100 : 1 | 120 mg oral morphine = 50 mcg/hr fentanyl patch |
8. Side Effect Management
Opioid Side Effects
Sedation
Nausea/vomiting
Constipation
Respiratory depression
Itching
Urinary retention
Preventive Strategies
Bowel regimen (e.g., senna, lactulose) with each morphine prescription.
Antiemetics (e.g., metoclopramide, haloperidol) for nausea.
Opioid rotation if side effects persist or if analgesia is inadequate despite dose escalations.
9. Putting It All Together: Case Example
Patient Scenario: A 70-year-old with advanced pancreatic cancer on 60 mg/day oral morphine for background pain.
Breakthrough Dose: 10% of 60 mg = 6 mg oral morphine PRN.
Day 1: Patient uses 4 breakthrough doses (6 mg each) → 24 mg total PRN.
If pain control is moderate but not optimal, you can apply either:
Titration by 25–50%: Increase to 75–90 mg/day (Method 1).
Add PRN Total: 60 mg + 24 mg = 84 mg/day (Method 2).
Day 2: Update the regular morphine schedule to the new total, recalculate the new breakthrough dose (10–20% of the new daily total), and continue monitoring pain and side effects.
10. Key Takeaways
Two Approaches to Morphine Titration:
Method 1: Increase total daily dose by 25–50% if pain remains uncontrolled.
Method 2: Add the previous day’s total PRN usage to the next day’s baseline dose.
Start Low, Go Slow: Minimize side effects in opioid-naïve patients.
Scheduled (ATC) + PRN: Ensure continuous pain control with a plan for breakthrough flares.
Monitor and Adjust: Pain scores, sedation, respiratory rate, bowel function.
Adjuvants & Supportive Measures: Essential for comprehensive care.
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