Pain control

NSAIDS

  Dose Notes
Ibuprofen 400 mg PO q4-6hrs  
Ketorolac (Toradol) 15 mg IV x 1 or q6hrs, max 60 mg/day Can use IV when NPO; good for GU/abdominal pain (e.g. kidney stones)
     
  • NSAIDs are generally equivalent in terms of pain relief
  • Side effects:
    • GI bleeding/mucosal damage (COX-1 inhibition)
      • Risk of GI side effects (bleeding/mucosal damage) - ASA + NSAID; 2 NSAIDs at once
      • GI-friendlier: meloxicam, celecoxib (more COX-2 selective)
    • renal impairment (caution in dehydration, renal dysfunction)
    • platelet dysfunction (caution in post-op, bleeding disorder, elderly/infants)

Tylenol

  • Adults - 650-1000 mg q6 hrs (max 4000 mg/day)
    • Max 2000-3000 mg/day if hepatic impairment
  • Peds - 10-15 mg q4-6 hrs PRN
  • Side effects
    • Fewer side effects than NSAIDs
    • Relative contraindication in liver damage; overdose → irreversible hepatic necrosis
  • Acetaminophen overdose management: ___

Adjuvant analgesic agents

  • Neuropathic pain agents
    • First line: gabapentin, pregabalin, duloxetine, venlafaxine, TCAs
  • Muscle relaxers
    • Cyclobenzaprine, baclofen, methocarbamol, tizanidine
  • Topical analgesics
    • Lidocaine patches/cream 4-5%
    • Capsaicin
    • NSAID creams/patches
  • Pain service can determine if patient is candidate for nerve blocks, injections, epidurals

Opioids

ME = morphine equivalent (IV) - divide morphine dose by this factor to get appropriate dose

  • Typical morphine dose: 4 mg IV (range 2-6 depending on weight)
  • Dilaudid is 5-7 x more potent than morphine! Normal dose is ~ 0.2-0.4 mg; do not dose 2 mg like morphine!
  • Switching between opiates in long-standing use - cross-tolerance makes response unpredictable; decrease dose by 25% when first switching
  • Long-acting opiates (MS Contin, OxyContin) - use only for opioid tolerant with mod/severe pain
ME Opiate Dose Notes
100 Fentanyl (IV) 25-50 mcg q1-2h Available in dermal/buccal patch - pain service consult 
5 Hydromorphone (IV) 0.2-1 mg q3-4h = dilaudid; also caution in renal impairment but less so than morphine
1.5 Oxycodone (PO) 5-10 mg q4-6h + acetaminophen = percocet (5/325 mg)
  Oxycodone SR (PO) 10 mg start q8-12h = oxycontin
1 Hydrocodone (PO) 5-10 mg q4-6h + acetaminophen = vicodin, norco (5/325 mg)
1 Morphine (IV) 1-4 mg q3-4h Metabolites (morphine 6, 3 glucoronide) are active; renally cleared (avoid in renal impairment, can get oversedation); a/w histamine release
0.3 Morphine (PO) 10-30 mg q3-4h
  Morphine SR (PO) 15 mg start q8-12h = MS Contin
0.15 Codeine (PO) 15-30 mg q4-6h Avoid due to ↑risk of resp depression/death, esp. in peds
0.1 Tramadol (PO) 25-50 mg q4-6h Dose adjust with renal/hepatic disease; caution for serotonin syndrome with other drugs

Side effects

  • cognitive disturbance, sedation, respiratory depression
  • n/v, constipation, urinary retention

PCA

  PCA dose Lockout Basal rate/hr Loading dose
morphine 1-2 mg 8-10 min 50-100% of PCA dose 2-4 mg
hydromorphone 0.25-0.5 mg 8-10 min  50-100% of PCA dose 0.5-1 mg
*fentanyl 10-25 mcg  8-20 min  ≤ 25 mcg/hr 25-50 mcg 
  • Generally safe way to give opioids (if they take too much they will fall asleep and not push the button anymore...)
    • *call pain consult if wanting to give fentanyl PCA
  • Indications
    • 6-7 y/o can push button
    • post-op pain management
    • moderate to severe pain requiring frequent doses of IV opioids and unable to take PO
    • Uncontrollable pain - short-term/24 hrs to gauge opioid requirements, then transition dose to PO
    • Palliative care/end-of-life pain control
    • Sickle cell vaso-occlusive crisis

Narcan (naloxone) if suspicious for opioid overdose (heroin/pain meds, ↓RR)

  • Goal - give enough to breathe adequately, not for full alertness
    • Use slow titration: abrupt withdrawal → pain, agitation, tachycardia, HTN, n/v
    • Rarely, flash pulmonary edema after large doses (CXR if concerned)
  • Dosing
    • 1 ampule = 0.4 mg in 10 mL 
    • Opioid OD: 0.4 - 2 mg in slow IVP (IV pushes) q2-3 min (1-5 amps)
    • Post-op (reversing anesthesia): 0.1-0.2 mg slow IVP q2-3 min (1/2 amp)
  • If 5 amps doesn't fix it, reconsider Dx...
  • Can give SQ/IM if no IV access, but slower absorption/delayed elimination
  • Narcan will wear off (t1/2 ~ 90 min) before pain meds/heroin - may need to redose if recurrent hypoventilation

Other notes

  • Pain management in breastfeeding women - oxycodone < 30 mg/day is safe for newborns. Rule of thumb: if the mother does not feel intoxicated, then it is OK for the baby.
author: last edited: Nov. 13, 2018, 5:22 p.m. | pk: 37 | unpublished