Medically Complicated Back Pain

Geriatrics, CKD and Liver Failure

Open Handout

 


 
 

  • Geriatric Back Pain
    • What makes assessing and treating back pain in older patients challenging?
      • More time needed to take a history
      • May have a different “pain” vocabulary
      • Difficult to perform and interpret an exam
      • More potentially dangerous causes of back pain
      • Difficulty interpreting imaging
      • Difficulty with choosing medicines for treatment (both because of age and co-morbidities)
    • DDx for an older person presenting with back pain. How do these present?
      • Cancer
        • Hx: constant, unrelated to position, disturbs sleep, progressive despite tx, wt loss
        • Risk factors: 7% of LBP over age 50, hx CA
        • Mets from breast, lung, kidney, prostate. MM. Pancreatic carcinoma, renal cell CA, intrapelvic tumors, lymphoma w/ retroperitoneal LAD
      • AAA (often assoc w/ abd pain, men > women, may radiate to hips/thighs, inc risk w/ PVD)
      • Compression fracture (sudden, severe, minimal trauma, women > men, exam may show kyphosis, can be seen on plain films, bone scans, or MRI. OK when still, painful w/ motion)
      • Osteoarthritis (insidious, worse w/ activity)
      • Polymyalgia rheumatica (sudden, neck/back/shoulder/hip stiffness, high sed rate, responds to prednisone)
      • Spinal stenosis (due to facet jt hypertrophy & disc herniation, bilateral leg pain/numbness/weakness improved with sitting, flexion, check peripheral pulses to distinguish vasc from neuro claudication)
      • Disc disease
      • Fibromyalgia (women > men)
      • Trochanteric bursitis (worse on hip abduction)
      • Paget disease
      • Parkinson’s (increased mm tone/stiffness)
      • Diffuse idiopathic skeletal hyperostosis (ossification of spinal ligaments, usually men > 50)
    • What medicines normally used for treating back pain can be dangerous in an older person? (See Beer’s List)
      • NSAIDs (GI bleeding risk, possible increased CAD risk, nephrotoxicity in diabetes)
      • ASA – GI bleeding risk, caution if underlying bleeding disorders
      • Tramadol – possible serotonin syndrome with SSRIs
      • Methadone – possible serotonin syndrome with SSRIs, prolonged QT syndrome
      • Opiates – possible altered mental status, constipation, can cause obstruction in BPH, slower clearance of metabolites, may slow respiration and cause CO2 retention in COPD
      • Tricyclic antidepressants – altered mental status, prolonged QT syndrome, constipation, may induce arrhythmias
      • Benzodiazepines – increased fall risk, altered mental status
      • Muscle relaxants – sedation, weakness, anticholinergic side effects, can cause obstruction in BPH
      • Steroids – altered mental status, increased fracture risk with long-term use
      • Anticonvulsants – sedation, ataxia, dizziness
    • Some general principles
      • Meds – start low and go slow
      • Tylenol first
      • Don’t forget non-pharmaceutical treatments
      • Consider x-ray in an older pt whose pain isn’t improving after 4 wks, U/S if you suspect AAA, CT or MRI if you suspect malignancy
  • Back Pain and Kidney Disease
    • Same WHO stepwise guidelines
    • Tylenol first
    • Most narcotics are eliminated hepatically – except methadone, which is both hepatic and renal
    • However, narcs like morphine, oxycodone, propoxyphene and meperidine have active metabolites whose elimination depends on GFR – so dose-adjust and use longer intervals
    • Avoid propoxyphene (Darvocet) and meperidine (Demerol)
    • Tramadol – max 50mg BID due to prolonged elimination
    • Can use NSAIDs, but caution in the elderly
    • Adjust dose and monitor for toxicity
  • Back Pain and Liver Disease
    • For meds taken orally, first-pass metabolism isn’t great – so bioavailability of narcotics and benzos are increased. Especially bad in pts with viral or alcoholic hepatitis (as opposed to malignant liver dz). Again, start low and go slow. Opioids can precipitate encephalopathy.
    • Decreased albumin and increasing ascites changes the volume and distribution of meds
    • Tylenol OK in conventional doses – so is amitriptyline
    • Unclear whether NSAIDs are verboten. Naproxen – decrease dose 50%
    • Morphine CR – accumulates – so decrease frequency
    • Avoid oxycodone (or decrease dose), codeine, tramadol
    • Fentanyl – the opioid of choice?
    • Anticonvulsants – more data needed. Avoid carbemazepine.
    • Benzos – be extremely careful. If you must, Ativan seems safest.