What pain medication should I give a patient with severe foot pain preventing ambulation and concurrent back pain?

Pain Management for Severe Foot and Back Pain

For a patient with severe foot and back pain preventing ambulation, initiate immediate-release opioids (oxycodone 5-15 mg or morphine equivalent every 4-6 hours) combined with scheduled acetaminophen (1000 mg every 6 hours, maximum 4000 mg daily), and add gabapentin (starting 100-300 mg nightly, titrating to 900-3600 mg daily in divided doses) if neuropathic features are present. 1, 2, 1

Immediate Management Approach

First-Line Combination Therapy

For severe pain preventing ambulation, you need aggressive multimodal analgesia:

• Start with immediate-release opioids at 5-15 mg oxycodone (or morphine equivalent) every 4-6 hours as the severity warrants urgent relief 1, 2
• Add scheduled acetaminophen 1000 mg every 6 hours (maximum 4000 mg daily) as it provides additive analgesia with opioids 1, 3
• Consider NSAIDs (ibuprofen 600 mg every 6 hours or diclofenac 50 mg every 8 hours) if no contraindications exist, as they are particularly effective for musculoskeletal and inflammatory pain 1, 3

Assessment for Neuropathic Component

Determine if the foot pain has neuropathic features (burning, shooting, electric-like quality, numbness, tingling) as this changes your approach 1:

• If neuropathic features present: Add gabapentin starting 100-300 mg at bedtime, increasing by 50-100% every few days to 900-3600 mg daily in divided doses 2-3 times daily 1
• Alternative for neuropathic pain: Pregabalin 50 mg three times daily, increasing to 100 mg three times daily (more efficiently absorbed than gabapentin) 1
• Another option: Duloxetine 30 mg daily for one week, then 60 mg daily, which addresses both neuropathic pain and any concurrent depression 1

Back Pain Specific Considerations

For the back pain component specifically:

• NSAIDs are particularly effective for low back pain and should be first-line if tolerated 1
• Consider adding a muscle relaxant for acute back pain if muscle spasm is present (though evidence is limited, they provide short-term relief) 1
• Tramadol 50-100 mg every 4-6 hours is an alternative that works on both opioid and monoamine receptors, providing moderate analgesia with lower abuse potential than traditional opioids 1, 3

Opioid Prescribing Specifics

When prescribing opioids for this severe presentation 2:

• Titrate based on response within the first 24-72 hours, monitoring closely for respiratory depression 2
• Prescribe around-the-clock dosing rather than as-needed for severe continuous pain to prevent pain recurrence 2, 4
• Plan for short-term use only (typically 3-7 days for acute severe pain), with reassessment before any continuation 1, 3
• Prescribe a bowel regimen immediately (stimulant laxative plus stool softener) as constipation is predictable with opioids 1

Critical Safety Considerations

Screen for contraindications before prescribing 1, 3:

• NSAIDs: Avoid in patients with history of GI bleeding, cardiovascular disease, chronic kidney disease, or concurrent anticoagulation 1
• Acetaminophen: Reduce dose to 2000 mg daily maximum in patients with hepatic disease, malnutrition, or severe alcohol use disorder 1, 5
• Opioids: Assess risk factors for abuse/misuse, avoid in patients with severe respiratory disease, and use extreme caution with concurrent benzodiazepines or alcohol 2, 1
• Gabapentin/Pregabalin: Require dose adjustment in renal insufficiency 1

Transition Plan

Within 48-72 hours, reassess pain control 2, 3:

• If pain remains severe (≥7/10) despite adequate dosing, consider switching to a different opioid or adding adjunctive agents 1
• If pain improves to moderate levels (4-6/10), begin tapering opioids and transition to scheduled NSAIDs/acetaminophen with opioids only for breakthrough 3
• If neuropathic pain persists, continue titrating gabapentin/pregabalin as these require 1-2 weeks at therapeutic doses for full effect 1

Common Pitfalls to Avoid

• Do not prescribe opioids as-needed only for severe continuous pain—this leads to inadequate analgesia and clock-watching behavior 2, 4
• Do not use codeine or tramadol as first-line for severe pain—they are too weak and have unpredictable metabolism 1, 3
• Do not forget the bowel regimen—opioid-induced constipation is universal and preventable 1
• Do not combine multiple long-acting opioids or use transdermal fentanyl for acute pain—these are only for stable chronic pain 1, 4
• Do not use pethidine (meperidine)—it has toxic metabolites and is contraindicated in most settings 6, 5