Neuropathic Pain Flashcards
Diagnosing Neuropathic Pain
- Imaging
- Physical Examination
- Mental Assessment
Acute Pain
Requires temporal pain management
Chronic Pain
- Pain continues beyond the expected time of tissue healing
- Requires long-term pain management
Nociceptive Pain
- Somatic, visceral, or inflammatory pain
- Peripheral stimuli (temperature, mechanical, or chemical)
Non-nociceptive Pain
- Neuropathic pain
- Functional pain
Inflammatory Pain
Tissue damage or inflammatory reactions
Neuropathic Pain
Central and peripheral nerve damage
Functional Pain
Normal nerve function but abnormal conduction
Central Neuropathic Pain Syndrome
Nerve damage on CNS (brain or spine)
Peripheral Neuropathic Pain Syndrome
Nerve damage on peripheral nervous system
Ascending Pathway + Pain
- Helps send the signal of pain
- Facilitates substance P, glutamate, and nerve growth factor
Descending Pathway + Pain
- Helps with the suppression of pain sensation
- Inhibits via NE, 5HT, DA, and opioids
1st Line Treatment + Neuropathic Pain
- TCAs
- SNRIs
- Ca++ channel ligands
If patient is well controlled and has no/minimal ADRs…
Continue on current regimen or consider dose adjustment
If patient has partial improvement but needs more…
Add an additional first-line agent or adjust the dosage
If patient has no improvements or significant ADRs…
Try a different first line agent or adjust the dosing
When to move onto 2nd line therapy…
-If ALL first line agents and their combinations have failed
OR
-All first line agents are CI
2nd Line Treatment + Neuropathic Pain
- Capsaicin topical
- Lidocaine topical
- Tramadol
- *Can combine these with third-line agents**
3rd Line Treatment + Neuropathic Pain
- Antidepressants (SSRIs)
- Anticonvulsants (CBZ, OXC, LAC, LTG, TPM, etc.)
- Topical agents (ketamine)
- Botulism toxin A
Ca++ Channel Ligand Examples/Dosing
- Gabapentin: 400-1200 mg TID
- Gabapentin ER: 600-1800 mg BID (postherpetic neuralgia in adults)
- Pregabalin 150-300 mg BID
SNRI Examples/Dosing
- Duloxetine: 60-120 mg QD
- Venlafaxine: 150-225 mg QD
TCA Examples/Dosing
- Amitriptyline, nortriptyline, imipramine, clomipramine
- All 12-150 mg/day, QD or BID dosing
- NOT recommended at dose of >75 mg
- NOT recommended for elderly, anticholinergic ADRs
Ca++ Channel Ligand MoA/ADR
- Block nerve impulse by binding to Ca++ channels
- Decrease Ca++ influx, which decreases excitatory neurotransmitters, which reduces pain nerve firing
- ADRs: sedation, peripheral edema
SNRI MoA/ADRs
- Block reuptake of NE and 5HT
- Overall well-tolerated and safer than TCAs
- ADRs: sedation, GI upset, insomnia, headaches
TCAs MoA/ADRs
- Effective to treat continuous burning pain
- Blocks voltage-gated Na channels
- Antagonize NMDA receptors and block alpha adrenergic receptor
- ADRs: sedation, orthostatic hypotension, weight gain, cardiotoxicity, ANTICHOLINERGIC effects
Nonpharm Options
- Exercise
- Physical therapy
- Oriental medicine: acupuncture, tai chi, traditional Chinese medicine
- Massage therapy
- Chiropractic
- Biofeedback
- Cognitive behavioral therapy
- Mindfulness based stress reduction
- Herbal medicine
- TENS unit
- Surgery
Drugs + Obese Patients
AVOID
- Valproic acid
- Gabapentin
- Pregabalin
POSSIBLE BENEFIT
-Topiramate
Drugs + Epileptics
AVOID
-Bupropion (decreases seizure threshold)
POSSIBLE BENEFIT
-Antiepileptic drugs
Drugs + Migraines
POSSIBLE BENEFIT
-Topiramate
Drugs + Anxiety
POSSIBLE BENEFIT
- Gabapentin
- Pregabalin
Drugs + Depression
POSSIBLE BENEFIT
-SNRIs
Drugs + Sleep Issues
POSSIBLE BENEFIT
- Gabapentin
- Pregabalin
- TCAs
Drugs + Geriatrics
AVOID
-TCAs
