Pain Management Flashcards
Non-opioid classes of drugs used for pain management
- Antidepressants
- Anticonvulsants
- Neuroleptic agents
- Corticosteroids
- Spasmolytics
- Cannabinoids
Tricyclic indications for pain management
Neuropathic pain
Eg. Amitriptyline
Gabapentin
Drug class and pain management indications
Anticonvulsant: Inhibits GABA inhibition, binds to Na+,Ca+ channels in nerve cell
Used in chronic pain, fibromyalgia, post herpetic neuralgia, neuropathic pain
Pregabalin (Lyrica)
Class and pain management indications
Anticonvulsant: Inhibits GABA inhibition, binds to Na+,Ca+ channels in nerve cell
Uses include fibromyalgia, diabetic neuropathy, post herpetic neuralgia
Also associated with improved sleep and decreased anxiety
Spasmolytics
Examples and uses
Aka muscle relaxants
Methocarbamol (Robaxin), Cyclobenzaprine (Flexaril)
Use: adjunct to rest, PT for MS pain, spasm
Methocarbamol (Robaxin)
Adverse effects
Sedation
Bradycardia
Disease Modifying Anti-Rheumatic Drugs (DMARDS)
Classifications and examples
- Conventional
- Methotrexate
- Hydroxychloroquine
- Leflunomide
- Sulfasalazine
- Biologics (TNF ⍺ Antagonists)
- infliximab (Remicade)
- adalimumab (Humira)
- certolizumab pegol (Cimzia)
- golimumab (Simponi)
- etanercept (Enbrel)
Methotrexate
Mechanism of Action and Indication
- Inhibits cytokine production (TNF, interleukins)
- Stimulates adenosine release (potent anti-inflammatory mediator)
- Folic acid antagonist which DNA synthesis in cancer cells at higher doses
Use: Rheumatologic disease, 1st choice DMARD
Methotrexate
Adverse Effects and Contraindications
- Nausea and vomiting
- Folate deficiency
- Oral ulcerations
- Headaches
- Fatigue (“methotrexate fog”)
- Liver fibrosis
Contraindicated in pregnancy (think folate deficiency)
Hydroxychloroquine (Plaquenil)
Mechanism of Action
RA: blocks the stimulation of CD4 T cells, causes down regulation of the immune response
Malaria: increases levels of cytotoxic heme which accumulates in parasites
Hydroxychloroquine (Palquenil)
Adverse Effects
- Prolonged QT
- H/A
- Rash
- Diarrhea
TNF ⍺ Antagonist
Mechanism of Action and Indications
Suppresses the physiologic response of TNF ⍺ in the inflammatory response
Used in autoimmune diseases which trigger the excessive production of TNF ⍺ (RA, Crohnes Disease, psoriasis, psoriatic arthritis)
What does TNF ⍺ do?
TNF ⍺ Antagonist
Adverse Effects and Precautions
Injection site reactions (common), Infections, Neutropenia, Paradoxical immune disease, Malignancy, Neurologic complications, exacerbation of HF
Live attenuated vaccines contraindicated
Need to screen for latent or active TB
Don’t give to MS patients
Corticosteriods
Pain management mechanism of action
- Inhibits arachidonic acid which is needed for cytokines
- Suppresses the immune system, inflammation and allergic response
Corticosteriod
Adverse Effects (systemic)
Euphoria or depression, insomnia, Cushing’s Syndrome, GI upset, impaired healing, elevated glucose levels (think about DM)
Corticosteriods
Adverse Effects (topicals)
- Systemic effects
- Atrophy (thin, transparent)
- Skin bleaching
- Striae
- Telangiectasias
- Purpura
- Acneiform eruptions
- Steroid rosacea
- Glaucoma/cataracts
- Growth suppression
- Rebound flare
What do Cyclo-oxygenase (COX) enzyme do?
Celecoxib
Selective Cox-2 inhibitor
Decreased GI effects but associated with higher risk of MI
NSAID indications
- Mild to moderate pain
- Osteoarthritis
- Rheumatoid Arthritis
- Mild to moderate pain
- Tendonitis
- Synovitis
- Primary dysmenorrhea
NSAID adverse effects
NSAIDS significantly increased the risk of a second MI in patients with known CVD
Nephrotoxicity
GI upset
Fluid retention
Avoid in late pregnancy
Opioid receptors
◦Mu
◦Located at supraspinal and spinal sites
◦Analgesia and respiratory depression
◦Mioisis, euphoria, reduced g.i. motility
◦Kappa
◦Dorsal horn of spinal cord and brain stem
◦Analgesia, miosis, sedation
◦Delta
◦Binding sites for endogenous peptides
◦Analgesia, dysphoria, delusions, hallucinations
Major opioid effects
- Analgesia
- Respiratory depression
- Euphoria
- Sedation
- Decreased GI motility (constipation)
- Bradycardia
- Nausea/vomiting
- Miosis
- Cough suppression
Pearls for prescribing opioids
Usually schedule II controlled substance (no refills, 30 day supply)
Check PDMP (regulations vary by state) and DOCUMENT!
Prescribing opioids for acute pain
No more than 7 days (per MA law), do NOT give extra just in case
Use lowest effective dose
Always use IR formulations
Use in combination with non-opioids
Set reasonable expectations for pain management
Codeine
1/10 potency of morphine
Give for mild to moderate pain
Often given with Tylenol or cough suppressant
Nausea is common side effect
Oxycodone
1.5x as potent as morphine
Give for moderate to severe pain
Can be given in combo with acetaminophen or NSAID or alone
Higher risk for abuse
Hydrocodone
Give for moderate to severe pain
Only available in combo with acetaminophen or ibuprofen
Fentanyl
50-100x more potent than morphine with rapid onset
Given for moderate to severe pain, pre and post op, and anesthesia adjunct
Methadone
Not used first line for pain management
Requires special liscene for MAT
Tramadol
Binds to mu receptors in the CNS inhibiting pain pathways, altering pain perception and response, inhibiting uptake of norepinephrine and serotonin
1/10th potency of morphine
Less respiratory depression compared to other opioids
Risk for serotonin syndrome
MME goals
Goal for lowest MME possible, try to keep under 50MME/day
Use caution and justify use >90MME/day
