Analgesics for musculoskeletal pain Sydney Broome Fremantle

EJ Visser Churack Chair UNDA 2018 copyright Pain Nociceptive pain Neuropathic pain Due to a lesion or disease of the somatosensory nervous system Nociplastic pain Sensitization (amplification) Modulation Allodynia EJ Visser Churack Chair UNDA 2018 copyright

EJ Visser Churack Chair UNDA 2018 copyright Aims of analgesia Pharmacotherapy: part of a multimodal pain Mx approach Acute pain relief acute to chronic pain transition functional rehabilitation (physiotherapy) risk of adverse effects chemical coping, addiction Mx chronic pain EJ Visser Churack Chair UNDA 2018 copyright

Lets review the drug cupboard

Paracetamol Not sure how paracetamol works? Maximum 8 per day COX-2, ‘cannabinoid’, serotonin? Maximum 8 per day Mainstay analgesic in most pain protocols No good for acute or chronic pain (Cochrane) individual responders older patients Combination paracetamol analgesics are more effective

Analgesia league table NNT Celecoxib 400 2 Ibuprofen 400 2.5 Paracetamol 500 + ibuprofen 200 1.8 Paracetamol 650 + tramadol 75 2.6 Panadeine forte 60/1000 3 Paracetamol 1000 4 Oxycodone 5 mg 4 Tramadol 100mg 5 Codeine 60mg 17

NSAIDs & coxibs NSAIDS: ibuprofen, aspirin COXIBS: celecoxib (COX-2 selective) Anti-inflammatories Prostaglandin synthesis (COX) Good prostaglandins (housekeeping) Renal & gastric risk Cardiovascular risk Bleeding risk Gut Airway Kidney Bone healing Vessels Platelets Tissue healing

NSAIDs & coxibs Celecoxib Ibuprofen, naproxen, diclofenac Effective for acute pain (NNT <3) ≤7 days Not for chronic pain Rapid-acting formulations ARE better Side effects (belly, bladder, bleeding)

Analgesia league table NNT Celecoxib 400 2 Ibuprofen 400 2.5 Paracetamol 500 + ibuprofen 200 1.8 Paracetamol 650 + tramadol 75 2.6 Panadeine forte 60/1000 3 Paracetamol 1000 4 Oxycodone 5 mg 4 Tramadol 100mg 5 Codeine 60mg 17

Tramadol Opioid, noradrenaline, serotonin Acute pain Neuropathic pain (NNT 4) ↓ Respiratory depression & constipation ↓ Addiction (S4) Ineffective in 10% (prodrug, 2D6 enzyme) Renal accumulation, seizures, interactions, serotonin Serotonin Noradrenaline Opioids

Analgesia league table NNT Celecoxib 400 2 Ibuprofen 400 2.5 Paracetamol 500 + ibuprofen 200 1.8 Paracetamol 650 + tramadol 75 2.6 Panadeine forte 60/1000 3 Paracetamol 1000 4 Oxycodone 5 4 Tramadol 100 4 Codeine 60 15

Tapentadol (Palexia) ‘Weak’ opioid (S8) & noradrenaline analgesic Similar to tramadol without serotonin ↓ Side effects Acute pain Neuropathic pain Chronic pain

Opioids for chronic pain Poor risk vs benefit Don’t work well (NNT = 8, NNH = 4) (Level I) Risk of adverse effects classical side effects, tolerance, hyperalgesia, overuse, addiction Contraindicated in non specific spinal pain, fibromyalgia OK to trial in >60s with spondylosis or OA joint pain 3Ts: tramadol SR, tapentadol SR, transdermal buprenorphine Ceiling dose is ≤ 60 mg oral morphine equivalents/day

Combination analgesics For acute pain only Paracetamol 500 mg/ ibuprofen 200 mg (OTC) Paracetamol 325 mg/ tramadol 37.5 mg (Zaldiar) (script) Paracetamol 500 mg/ codeine 30 mg (script) Ibuprofen 200 mg/ codeine 12 mg (Nurofen plus) (script)

Analgesia league table NNT Celecoxib 400 2 Ibuprofen 400 2.5 Paracetamol 500 + ibuprofen 200 1.8 Paracetamol 650 + tramadol 75 2.6 Panadeine forte 60/1000 3 Paracetamol 1000 4 Oxycodone 5 4 Tramadol 100 5 Codeine 60 17

Antidepressants & anticonvulsants NOT effective for nociceptive pain Duloxetine (SNRI) is moderately effective (noradrenaline effect) Chronic LBP & knee pain Neuropathic pain (NNT 4) Pregabalin, gabapentin Not effective for LBP Radicular leg pain?

Other analgesics Topical NSAIDs OA knee, hands, enthesopathy, tendonopathy Topical capsaicin cream OA knee, hands Menthol 4% gel

EJ Visser Churack Chair UNDA 2017 copyright Steroids Oral (prednisolone) Acute inflammatory arthritis, tendonitis, enthesitis, myositis Early CRPS? Acute radiculopathy? Injection Radicular leg pain (transforaminal epidural) Knee, hip, shoulder, facet, SIJ, soft tissues EJ Visser Churack Chair UNDA 2017 copyright

EJ Visser Churack Chair UNDA 2017 copyright Distal limb injuries Vitamin C 1000 mg/d for 4 weeks  CRPS O2 free radical scavenger  neurogenic inflammation EJ Visser Churack Chair UNDA 2017 copyright

EJ Visser Churack Chair UNDA 2017 copyright Sleep & supplements Sleep Melatonin, valerian, lavender Amitriptyline, pregabalin Anti-inflammatories Curcumin PEA (lecithin nutraceutical) Chondroitin & glucosamine EJ Visser Churack Chair UNDA 2017 copyright

EJ Visser Churack Chair UNDA 2017 copyright Cutting edge? Neuroimmune & glial modulators Fibromyalgia, CFS, CRPS Melatonin Minocycline (antibiotic) Metformin (diabetes) Naltrexone EJ Visser Churack Chair UNDA 2017 copyright

EJ Visser Churack Chair UNDA 2017 copyright Controversies Codeine Cannabinoids Benefits < risks NNT 15 for both Individual responders? Muscle spasms Orphenadrine or baclofen (diazepam*) for muscle spasms EJ Visser Churack Chair UNDA 2017 copyright

Acute musculoskeletal pain Comfort measures (heat) Combination paracetamol/ibuprofen prn (≤ 4 days) Severe… Celecoxib 100-200 mg bd (≤ 7 days) Combination paracetamol/tramadol or codeine prn OR… IR tapentadol or oxycodone prn ≤ 4/24 prn, ≤ 4 x daily, ≤ 4 days

Acute severe radicular pain Neuropathic pain (nociceptive, muscle spasms) Analgesics are poorly effective (level I) Tramadol, tapentadol or oxycodone Pregabalin Steroids (transforaminal injection or oral) Natural history; improvement in 3-6 months

Thank you