What oral analgesic is appropriate for a patient with 10/10 severe pain limiting ambulation who has not responded to over‑the‑counter agents?

Oral Opioid Therapy for Severe Refractory Pain

For a patient with 10/10 severe pain unresponsive to over-the-counter medications, initiate immediate-release oral morphine 5-15 mg every 4 hours with rescue doses available, or alternatively oxycodone 20 mg, as these are first-line strong opioids for severe pain. 1

Immediate Treatment Strategy

First-Line Opioid Selection

• Oral morphine is the standard first-line strong opioid for severe pain when over-the-counter medications have failed 1
• Start with immediate-release morphine 5-15 mg orally for opioid-naïve patients 1
• Alternative option: oxycodone 20 mg orally as initial dose 1
• Hydromorphone 8 mg orally is another option, though it is 7.5 times more potent than morphine 1, 2

Critical Pre-Treatment Assessment

Before prescribing, you must rule out:

• Impending spinal cord compression 3
• Pathologic fracture 3
• Brain or epidural metastases 3
• Infection or obstructed viscus 3

Titration Protocol

Dosing Schedule

• Administer immediate-release opioid every 4 hours around-the-clock 1
• Provide rescue doses of 10% of the total daily dose for breakthrough pain 1, 2
• Patient may take rescue doses every hour for up to 4 consecutive hours before requiring reassessment 1
• Reassess pain intensity every 60 minutes after oral administration 3

Dose Escalation

• There is no maximum dose ceiling for pure opioid agonists like morphine, oxycodone, or hydromorphone 1, 4, 2
• Continue escalating until pain is controlled or side effects become unmanageable 4, 3
• If patient requires more than 4 breakthrough doses per day, increase the baseline long-acting formulation rather than continuing frequent rescue dosing 4, 2

Mandatory Concurrent Interventions

You must initiate these three interventions simultaneously with opioid therapy:

1. Bowel regimen (constipation is inevitable with opioids) 1, 3
2. Antiemetic availability 3
3. Continue non-opioid analgesics unless contraindicated 3

Conversion to Long-Acting Formulation

Once pain is controlled with immediate-release opioids:

• Calculate the total 24-hour opioid requirement 1, 4
• Convert to extended-release morphine or oxycodone by dividing total daily dose by 2 for twice-daily dosing 4
• Continue providing immediate-release formulation for breakthrough pain 1

Critical Safety Considerations

Renal Function

• Avoid morphine entirely in patients with renal failure due to accumulation of toxic metabolites causing confusion, myoclonic jerks, and hyperalgesia 4
• Use fentanyl or hydromorphone instead if significant renal impairment exists 4

Age Adjustment

• For patients >70 years old, reduce initial dose to approximately 10 mg/day oral morphine due to decreased renal function and increased opioid sensitivity 3

Common Pitfalls

• Never stop opioids abruptly—taper by 30-50% over approximately one week if discontinuation is needed 1
• Do not combine opioids from different receptor categories (pure agonist, partial agonist-antagonist, mixed agonist-antagonist) 1
• Drowsiness during initial titration is expected and usually resolves within days 1
• Psychological dependence is rare in patients with legitimate pain 1

FDA Indication

Oxycodone is FDA-approved for management of pain severe enough to require an opioid analgesic when alternative treatments are inadequate 5