Management of Severe Back Pain on Oxycodone and Baclofen
Add an NSAID (ibuprofen 400-600 mg every 6-8 hours or naproxen 500 mg twice daily) as the next step, since NSAIDs provide superior pain relief compared to opioids alone for back pain and the patient is already on a muscle relaxant. 1
Rationale for Adding NSAIDs
- NSAIDs are more effective than opioids for acute low back pain, with evidence showing they provide slightly better short-term symptomatic relief and have fewer adverse effects than opioids 1
- The American College of Physicians recommends NSAIDs as first-line therapy before escalating opioid doses 1
- NSAIDs combined with muscle relaxants (like the baclofen already prescribed) provide consistently greater pain relief than either agent alone 2, 3
Reassess the Current Regimen
- Baclofen has limited evidence for low back pain despite being prescribed, with only 2 trials supporting its use compared to 8 trials for tizanidine 1, 2
- Consider switching from baclofen to tizanidine 2-4 mg three times daily, which is the preferred muscle relaxant with superior evidence for back pain 2, 3
- The current oxycodone 10 mg dose is reasonable, but avoid escalating opioids further as they show no superiority over other therapies and carry higher risks of long-term disability when used early in treatment 1
If Radicular Symptoms Present
- Add gabapentin (starting 300 mg at bedtime, titrating to 300-600 mg three times daily) if the patient has leg pain or radiculopathy, as it demonstrates small but significant benefits specifically for radicular symptoms 2, 3
- The combination of tizanidine plus gabapentin may be particularly beneficial for radiculopathy 2
Critical Safety Considerations
- Monitor for baclofen toxicity if the patient has any renal impairment, as baclofen is 69-85% renally cleared and can cause encephalopathy, ataxia, and dystonia even at low doses in renal disease 4
- All muscle relaxants increase CNS adverse events 2-fold (sedation, dizziness), which compounds with opioid side effects 1, 2
- Limit muscle relaxant duration to 1-2 weeks maximum for acute pain, as evidence for longer-term use is lacking 2, 3
What NOT to Do
- Do not increase the opioid dose as first-line escalation—opioid use beyond 7 days for acute low back injury significantly increases risk of long-term disability 1
- Do not add systemic corticosteroids, as they provide no benefit over placebo for back pain with or without sciatica 2, 5
- Avoid combining multiple sedating agents (opioid + muscle relaxant + benzodiazepine) due to compounded respiratory depression risk 1
Monitoring Plan
- Reassess pain and function within 2-4 days after adding NSAID therapy 2
- If no improvement after a time-limited course (1-2 weeks), reconsider the diagnosis and evaluate for alternative therapies or specialist referral 2, 3
- Screen for cardiovascular and gastrointestinal risk factors before prescribing NSAIDs, particularly in elderly patients 5