Medication Management of the
Chronic Pain Patient
Benjamin Meeks, CFNP
Pain Medicine Associates
Overview

Overview of Pain Transmission

Rational Poly-pharmacy

NASIDS

Antidepressants

Anti-Seizure Medications

Topical Medications

Opiates

Cannabinoids
Transmission of Pain

Peripheral Sensitization

Peripheral Neurons

Ascending Spinal Cord

Brain Structures/Mechanisms

Descending Spinal Cord
Peripheral Sensatization

Painful Stimuli

Sodium and Calcium Channel Depolarization

Glutamate

Substance P

Bradykinin

Prostaglandin

Tumor Necrosis Factor Alpha

Glial Cells, Schwann Cells, Microglia, Astrocytes

Nitric Oxide

Arachidonic Acid
Ascending Spinal Cord

Dorsal Horn

NMDA, AMPA G-Protein and Tyrosine Receptors

Summation Response

Spinothalamic Tract
Brain

Singnal from Spinothalamic Tract

Concioius perception of pain

Serotonin/Norepinephrine

Endogenous Opioids in Periaqueductal Gray
Descending Spinal Cord

Norepinephrine (Inhibitory)

Serotonin (Inhibitory and Excitatory)

Dopamine (Inhibitory and Excitatory)
Rational Poly-Pharmacy

Norepinephrine

Opiate Receptors – Peripheral and Central Afferents

Peripheral Sensitization

COX-2/Acid Sensitive Channels

Subsbstance P

Calium and Sodium Channels

Prostaglandins
“Multidrug analgesic approaches take advantage
of complementary mechainisms of different drug
classes to enhance analgesia”
NSAIDS

Inhibit Cyclooxygenase, prostaghaldins and
acid-sensative ion channels

GI, Kidney Risk, Coronary Risk

Opiate Sparring
Antidepressants

TCA's

Norepinephrine,Imipramine, Amitryptiline,
Desipramine

Anticholinergic Side Effects

Cariovascular Toxicity

SSRI's – Little data to support use in pain

Venlafaxine – Pain data is mixed

Milnacipran – Norepinephrine Reuptake Inhibitor


FDA approved fibromyalgia
Duloxetine

Inhibit serotonin and norephephrine uptake

FDA approved for diabetic peripheral neuropathy, low
Antiseizure Medications

Stabilize Calcium and/or Sodium Channels

Increases Spinal Norepinephrine Concentration



Carbamaepine, Oxycarbamazepine,
Gabapentin, Pregabalin, Topiramate,
Lamotragine
Extensively studied in peripheral neuropathic
states
Dizzyness, somnolence and peripheral edema
Topical Medications

Capsaicin – Substance P depletion


Lidocaine – Sodium Channel Blockade



OTC Ointment – prescription patch
3 – 10% Ointment or 5% patch
Compounded Ointments/Gels

Lidocaine, Baclofen, Ketoprofen, Amitrytyline,
Gabapentin, Ketamine, Cyclobenzaprine

Opioids – No controlled studies
Topical Diclofenac

Gel or patch

Better tolerated than by mouth
Opiates

Immediate Release

Extended Release
Immediate Release Opiates

May be associated with increased risk of tolerance and
addiction compared to extended release opiates

Analgesic Half-life 2 – 4 hours

Onset by mouth 5 – 40 minutes

Oxycodone, oxymorphone, codeine, morphine,
hydrocodone, hydromorphone, tramadol, tapentadol

Constipation, nausea, confusion, dizzyness, itching

Indicated for as needed usage
Immediate Release Opiates


Buprenorphine – Mu agonist/antagonist long
half life suitable for once daily dosing
Methadone – Mu/NMDA agonist

Unpredictable half-life
Extended Release Opiates



May be associated with low risk of tolerance
and addiction
Indicated to chronic pain in patients who require
constant opiate dosing
MS ER tabs, MS ER Capsules, Hyromorphone
ER Tabs, Oxycodone ER Tabs, Oxymorphone
ER Tabs, Tramadol ER tabs, Tapentadol ER
Tabs, Fentanyl Patch, Buprenorphine Patch
Cannabinoids


Dronabinol FDA approved for chemotherapy
induced nausea and AIDS wasting
Smoked and Nebulized Cannabinoids activity at
Mu and Delta receptors

Does not alter opiate pharmacokinectics

Little placebo controlled data for chronic pain

Low dose nebulized canabinoid not assoctied
with “high”
Summary
Cyclooxgenase Calcium/Sodium Channels Norephrine Re-Uptake Mu-Agonists
NSAIDS
Gabapentin
Nortriptyline
Codeine
Diclofenac Patch
Carbamazepine
Amitryptline
Hydrocodone
Dicofenac Gel
Oxcarbamazepine
Desipramine
Hydromorphone
Compound Gels
Pregabalin
Imipramine
Tramadol
Zonisamide
Tramadol
Tapentadol
Lamotrgine
Tapentadol
Morphine
Topical Lidocaine
Duloxetine
Oxycodone
Savella
Oxymorphone
Methadone
Fentanyl
Buprenorphine
Questions?
Questions?