Pharmacotherapy of Pain: Adjuvant Analgesics - PowerPoint PPT Presentation

slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Pharmacotherapy of Pain: Adjuvant Analgesics PowerPoint Presentation
Download Presentation
Pharmacotherapy of Pain: Adjuvant Analgesics

play fullscreen
1 / 17
Pharmacotherapy of Pain: Adjuvant Analgesics
211 Views
Download Presentation
robin-mitchell
Download Presentation

Pharmacotherapy of Pain: Adjuvant Analgesics

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Pharmacotherapy of Pain: Adjuvant Analgesics

  2. Adjuvant Analgesics • Defined as drugs with other indications that may be analgesic in specific circumstances • Numerous drugs in diverse classes • Sequential trials are often needed

  3. Adjuvant Analgesics • Multipurpose analgesics • Drugs used for neuropathic pain • Drugs used for musculoskeletal pain • Drugs used for cancer pain • Drugs used for headache

  4. Class Examples Antidepressants amitriptyline, desipramine, nortriptyline, paroxetine,venlafaxine, citalopram, others Alpha-2 adrenergic tizanidine, clonidine agonists Corticosteroids prednisone, dexamethasone Multipurpose Adjuvant Analgesics

  5. Multipurpose Adjuvant Analgesics Antidepressants • Best evidence: 30 amine TCAs (eg, amitriptyline) • 20 amine TCAs (desipramine, nortriptyline) better tolerated and also analgesic • Some evidence for SSRI/SSNRIs/atypical antidepressants (eg, paroxetine, venlafaxine, maprotiline, bupropion, others) and these are better tolerated yet

  6. Multipurpose Adjuvant Analgesics Alpha-2 adrenergic agonists • Clonidine and tizanidine used for chronic pain of any type • Tizanidine usually better tolerated • Tizanidine starting dose 1–2 mg/d; usual maximum dose up to 40 mg/d

  7. Adjuvant Analgesics for Neuropathic Pain Class Examples Anticonvulsants gabapentin, valproate, phenytoin, carbamazepine, clonazepam, topiramate, lamotrigine, tiagabine, oxcarbazepine, zonisamide, levetiracetam Local anesthetics mexiletine, tocainide

  8. Adjuvant Analgesics for Neuropathic Pain Class Examples NMDA receptor dextromethorphan, ketamine Antagonists amantadine Miscellaneous baclofen, calcitonin Topical lidocaine, lidocaine/prilocaine, capsaicin, NSAIDs

  9. Adjuvant Analgesics for Neuropathic Pain Anticonvulsants • Gabapentin commonly used • Favorable safety profile and positive RCTs in PHN/diabetic neuropathy • Usual effective dose: 600–3600 mg/d and sometimes higher • Analgesic effects established for phenytoin, carbamazepine, valproate, clonazepam, and lamotrigine • Limited experience with other drugs

  10. Adjuvant Analgesics for Neuropathic Pain • Local anesthetics • Oral therapy with mexiletine, tocainide, flecainide • IV/SQ lidocaine also useful • Useful for any type of neuropathic pain

  11. Adjuvant Analgesics for Neuropathic Pain Miscellaneous drugs • Calcitonin • RCTs in CRPS and phantom pain • Limited experience • Baclofen • RCT in trigeminal neuralgia • 30–200 mg/d or higher • Taper before discontinuation

  12. Adjuvant Analgesics for Neuropathic Pain NMDA-receptor antagonists • N-methyl-D-aspartate receptor involved in neuropathic pain • Commercially-available drugs are analgesic: ketamine, dextromethorpan, amantadine

  13. Topical Adjuvant Analgesics • Used for neuropathic pain • Local anesthetics • Lidocaine patch • Cream, eg, lidocaine 5%, EMLA • Capsaicin • Used for musculoskeletal pains • NSAIDs

  14. Adjuvant Analgesics for Musculoskeletal Pain “Muscle relaxants” • Refers to numerous drugs, eg, cyclobenzaprine, carisoprodol, orphenadrine, methocarbamol, chlorzoxazone, metaxalone • Centrally-acting analgesics • Do not relax skeletal muscle

  15. Adjuvant Analgesics for Chronic Headache • Beta blockers • Anticonvulsants • Calcium channel blockers • Alpha-2 adrenergic agonists • Antidepressants • Vasoactive drugs • ACE inhibitors

  16. Adjuvant Analgesics for Cancer Pain • For bone pain • Bisphosphonates (eg, pamidronate, clodronate), calcitonin, radiopharmaceuticals (eg, Sr89, Sm153) • For bowel obstruction pain • Anticholinergics, octreotide

  17. Adjuvant Analgesics With Opioid Interactions • NMDA antagonists (eg, dextromethorphan, ketamine, amantadine) • Cholecystokinin-B antagonists (eg, proglumide) • Ultra-low doses of opioid antagonists