Acute and Chronic Pain

Adjuvant Therapy

• Acetaminophen: limit 3g/day (2g in liver pts).
  • Avoid if you are worried about masking fevers.
• NSAIDs: great for musculoskeletal, headache, and nephrolithiasis in eligible pts.
  • IV/PO ketorolac, ibuprofen, naproxen, etc.
  • Avoid in acute or chronic kidney disease and ↑ risk of bleeding. Caution in CAD/PVD.
• Topical analgesics: best for localized pain but utilized frequently as part of a multimodal regimen.
  • Lidocaine ointment/patches, menthol salicylate gel, Diclofenac gel for MSK pain.
  • Capsaicin gel for neuropathic pain.
• Neuropathic pain (burning, shooting, numbness/tingling).
• SNRIs and TCAs can provide additional benefits if a pt has comorbid depression, anxiety, or insomnia. Most agents take 6-8 weeks for peak effect.
• Gabapentin: Initial 100 to 300 mg 1 to 3 times daily. Can also be used for acute pain. Can be titrated up to 1200mg TID.
• Pregabalin: Initial: 25 to 150 mg/day in 2 to 3 divided doses. Has better bioavailability than gabapentin.
• Duloxetine: Initial 30 mg daily for 1 to 2 weeks, then increase to 60 mg daily as tolerated.
• Amitriptyline: Initial: 10 to 25 mg once daily at bedtime.
• Muscle relaxants: Should be used temporarily and intermittently but some benefit from longer-term use. Great for paraplegia, spinal injury, and spasticity.
  • Methocarbamol: Initial 500-1000mg 3 to 4 times. Preferred initial agent as has least SE.
  • Tizanidine: Initial 2 to 4 mg every 6 to 12 hours as needed and/or at bedtime. Important to watch out for withdrawal in pts that take frequently at home. May have off-target hypotension as SE.
  • Cyclobenzaprine: Initial 5 to 10 mg once daily before bedtime.
  • Baclofen: Initial 5 to 10 mg 2 to 3 times daily. Common in SCI and CP. Can
    also precipitate withdrawal if stopped suddenly.
  • Steroids: Especially helpful for visceral pain (pain from organ distension such as splenomegaly, hepatic capsular pain or bowel obstruction), often use dexamethasone IV.
  • NMDA antagonists: usually prescribed by pain management, can consider as a potential option if a pt’s pain continues to be difficult to control.
  • Memantine: Initial 5mg daily.

Renal dysfunction

• Avoid NSAIDs, morphine, and codeine.
• Safest opioids for renal dysfunction are fentanyl, buprenorphine.
• Gabapentin: Start with spot 100mg. Increased sedation risk.

Cirrhosis

Always avoid NSAIDs, morphine, codeine, hydromorphone.

Opioids: Increased accumulation of toxic metabolites or increased bioavailability of due to decreased first pass metabolism, liver synthetic dysfunction, and protein binding (hypoalbuminemia). May precipitate hepatic encephalopathy.

History of substance use disorder

• Generally recommended to continue home buprenorphine at admission to
  prevent withdrawal.
• Overnight, always review handoff as day team likely has specific plan in place.
• Typically rely on multimodal agents as above. However, pts with OUD can and do have acute, severe pain. NEVER withhold opiates if clinically appropriate, regardless of substance use history.
• Consider addiction psychiatry consult, palliative care consult, and/or chronic pain service consult.
• Consider consulting acute or chronic pain services for severe, uncontrolled pai.
• Can evaluate for ketamine or lidocaine drips, peripheral nerve blocks.

Non-pharmacologic Therapies

Pt’s will have varying opinions and responses on adjunctive therapies, but these can be as important as any pharmacologic therapy.

• CBT, personalized exercise regimen, PT/OT, chiropractor, acupuncture.
• Consider consulting chaplain, social work for support inpatient.

Pain Management Center at VUMC.

Pain Clinic at the VA (specify whether okay to initiate opioids).

Complementary and Integrative Health consult at VA, or Osher Center at VUMC.