psych/neuro neuropathic pain+headache and migraine

how does one practice opioid stewardship and individualized care

adjunct therapies for chronic pain can be utilized to treat sxs specific to the disease state/situation

what is neuropathic pain

pain from damage to the CNS or PNS

is stimulation of pain receptors required in neuropathic pain

no

what are the causes of neuropathic pain

damage to nerves - - diabetes, chemotherapy, infections

what are the presentation of neuropathic pain

(1) burning

(2) tingling

(3) shooting

what are the causes for chronic pain

(1) cancer

(2) arthritis

(3) musculoskeletal

(4) neuropathic

what is the pain management for mild pain (1-3)

around the clock (ATC) non-opioids (APAP, NSAIDs, adjunctive therapies)

what is the pain management for moderate pain (4-6)

continue mild pain therapy and may combine multiple non-opioid therapies + add low dose PRN opioids for breakthrough pain

what is the pain management for severe pain (7-10)

increase dose of PRN opioids

what are muscle relaxants used for

used as adjunctive therapy as symptomatic relief for acute lower back pain and muscle spasms

are muscle relaxants proven to be superior to tylenol or NSAIDs

no

when are muscle relaxants used

use an add-on therapy when already on adequate doses of APAP/NSAIDs

what is the duration of use for muscle relaxants

limit to shorter duration (2 weeks)

what do all muscle relaxants cause

CNS depression

what should you counsel pts on muscle relaxants

may cause drowsiness and sedative effects and anti-cholinergic effects

what are anti-spasmodics

(1) blocks nerve signaling from brain

(2) treats spasms resulting from peripheral musculoskeletal conditions

what are examples of anti-spasmodics uses

lower back injury, trauma, sprains and strains

what are anti-spastics

(1) blocks nerve signaling from spinal cord

(2) treats spasticity resulting from spinal motor neuron overactivity

what are examples of anti-spastic uses

multiple sclerosis, spinal cord injury, stroke, cerebral palsy, infection

what are the main anti-spasmodic muscle relaxants?

(1) Carisoprodol

(2) Cyclobenzaprine

t/f carisoprodol is frequently abused

true

should carisoprodol be avoided if possible

yes

what should the duration of carisoprodol be used for

limit to 2-3 weeks

if carisoprodol is used long term, what should be done to avoid withdrawal

taper over 14 days

how is carisoprodol metabolized

CYP2C19

what are the adverse effects of carisoprodol

CNS depression

what is the recommended max duration for cyclobenzaprine

2-3 weeks

what are the adverse effects of cyclobenzaprine

CNS depression, serotonin syndrome

what is the mechanism of muscle relaxation of methocarbamol

through general CNS depression

what are the main anti-spastic muscle relaxants?

(1) Baclofen

(2) Tizanidine

how does baclofen work

inhibits reflexes at the spinal cord

when is baclofen used

spasticity associated with MS/spinal cord lesions

what is baclofen also available as and for what

intrathecal injection for severe spasticity

what is the BBW for baclofen

acute withdrawal may lead to organ failure or death

what is the off-label use for baclofen

alcohol use disorder and hiccups

what are the adverse effects for baclofen

CNS depression and urinary retention

how does tizanidine work

centrally acting a-2 agonist

how is tizanidine excreted

renally

what are the adverse effects of tizanidine

CNS depression, hypotension, visual hallucinations

what are the main types of neuropathic pain?

(1) diabetic neuropathy

(2) postherpetic neuralgia

(3) trigeminal neuralgia

what is diabetic neuropathy

microvascular damage feeding small nerves from elevated blood sugar

⚫️ often peripheral

what is postherpetic neuralgia

complication of shingles

what is trigeminal neuralgia

damage to trigeminal nerve in the cranium from facial surgery

⚫️ characterized by intense facial pain

what is fibromyalgia

widespread musculoskeletal pain, overlaps with neuropathy

what is the pathophysiology of diabetic neuropathy

(1) pts with diabetes can experience oxidative stress and degeneration to internal components of cell, especially mitochondria

(2) in neuron, mitochondria must travel entire length of axon to supply axonal energy requirements

(3) metabolic injury occurs both at the cell body and during mitochondrial trafficking

(4) leads to bioenergetic failure, especially at the most distal portion of the axon

what is shingle caused by

varicella zoster virus (VZV), same virus that causes chickenpox

what happens when VZV reactivates

causes shingles,

what does shingles appear as

painful rash in the pattern of nerves

what might happen to the nerves after shingles

can get damaged, then the pt may experience postherpetic neuralgia, causing burning pain long after the rash disappears

what is the trigeminal nerve

large nerve that connects 3 primary nerves in the face (eyes, sinus, jaw)

how can the trigeminal nerve be damaged

facial trauma and dental procedures

describe the pain of trigeminal neuralgia

(1) shock-like

(2) shooting

3) stabbing

(4) sharp

what are the 1st line treatments for neuropathic pain

(1) antidepressants - TCAs, SNRIs

(2) AEDs

(3) topical therapy - localized pain

(4) combo therapy of non-opioids if monotherapy fails

what are the main gabapentinoid antiepiletics (AEDs)?

(1) Gabapentin

(2) Pregablin

what are gabepentionoids indicated for

neuropathic pain and postherpetic neuralgia

what is pregabalin also approved for

fibromyalgia

what are the main AEDs that contain Carbamazepine derivates

(1) Carbamazepine

(2) Oxcarbazepe

what are the main classes of antidepressants used for chronic pain?

(1) TCAs

(2) SNRIs

what are the topicals used for chronic pain?

(1) lidocaine 5% patch

(2) capsaicin

what is carbamazepine & derivatives indicated for

highly efficacious for trigeminal neuralgia

what are the BBW for carbamazepine and oxcarbazepine

SJS/TENs (avoid in asians), anemia and agranulocytes

what are the adverse effects of carbamazepine and oxcarbazepine

(1) CNS (dizziness and drowsiness)

(2) SIADH and hyponatremia

(3) hepatotoxicity

what are lidocaine patches effective in

post-herpetic neuralgia

what is the dose for lidocaine patches

apply 1 patch to affected areas, may leave for up to 12 hours in a 24 hour period

what are the consultation points for lidocaine patches

(1) apply on intact skin

(2) avoid exposure to heat (2) dispose by folding patch on adhesive side and throw away in trash

(3) may cut into smaller sizes

(4) AE: may cause local skin irritation

what is the MOA fo capsaicin

binds to TRPV1 receptor on C-nerve fibers, releasing substance P & depolarizing nerve

what is capsaicin for

neuropathic pain and muscle/joint pain

what are the consultation points for capsaicin

(1) 8% product is reserved for 3rd/4th line treatment and should only be applied by a healthcare provider

(2) apply only to intact skin and do not apply within 1 hours before or after bathing

(3) wash hands after applying

what are adverse effects of capsaicin

(1) local site burning

(2) erythema

(3) limb pain