Chronic Pain Management Flashcards
Describe Acute pain
- Results of trauma, surgical or infectious events
- Starts abruptly, resolves in days/weeks
- Self-limiting, biological purpose
Describe Chronic Pain
- Persists beyond normal time of healing/absence of healing
- > 1-3 months in duration or beyond healing time
- Disease
Define Allodynia & Hyperalgesia
- ALLODYNIA = Pain sensation in response to a non painful stimulus
- HYPERALGESIA = an exaggerated or prolonged response to a noxious stimulus
What examples of chronic pain?
- Cancer pain : Inflammation, Tissue Distortion, Nerve injury, Neuropathic pain
Visceral obstruction/distension, Ischemia - Osteoarthritis/DJD
- Oro-facial pain
- Intervertebral disc disease
- Tail/limb amputation
Arthritis case - how could we assess pain?
- QoL scale
- Liverpool OA Dogs (LOAD) questionaire
- Chronic pain assessment
What can be used for chrponic pain assessment?
- PRessure mats/ force plane for gait analysis
- Accellerometry
- Quantitative sensory testing (resp to stimuli)
- Pain trace
Describe NSAIDS as pain tx option (adverse effects)
- ≠ reaction to ≠ NSAIDs possible
- Washout period (7-14 days ??)
- Blood works + urine analysis before/ during treatment
- Constant monitoring
- Lean body weight dose
- Pair with food (some exceptions)
- Lowest effective dose if long term administration/ administration every other day
AEs of NSAIDS?
- Vomiting, diarrhoea, anorexia, gastro-intestinal ulceration & perforation
- Hepatotoxicity
- Renal Disease
- Coagulation
Describe Paracetamol for tx of pain?
- Licensed (dogs) with codeine for up to 5 days
- COX-3 inhibition (brain): antipyretic effect
- Use with NSAIDs or Corticosteroids??
What analgesic MOA for paracetamol?
- Prostaglandins inhibition
- Serotoninergic pathway activation
- Endocannabinoids enhancement
- L arginine/NO pathway
What category of pain meds do Frunevetmab (cats) / Bedinvetmab (dogs) fall into?
Anti-nerve Growth Factor (NGF) Monoclonal antibodies
How do we use Monoclonal antibodies?
- Inhibition of NGF mediated cell signalling to reduce pain
- Monthly subcutaneous injection
- Only licenced for treatment of PAIN associated with OA
- Relatively new product?
AEs & CI of Monoclonal antibodies?
- Contraindicated with NSAIDs (In humans)
- Allergic reaction, injection site reactions
- Safety with long term exposure & other medication unknown
What drugs can we use for neuropathic pain/ seizures?
Gabapentin/ Pregabalin
Describe use of gaba/pregaba
- Oral formulation
- Blockage of Ca2+ channels presynaptic neurons →↓ Ca2+ influx→ ↓ excitatory
neurotransmitters - Use in association with NSAIDs, opioids…
Side effects of Gaba etc?
Sedation, ataxia, vomiting, diarrhoea, increased appetite?
What is Amantidine & what is it used for?
- Chronic pain
- Antagonist of N-methyl-D-aspartate (NMDA) receptors: blockage of pain
transmission
What part of CNS does Amantidine work on? what does this mean for duration of aciton ?
dec central sensitization/hyperalgesia: long onset of action
Side effects of Amantidine?
lethargy, gastro-intestinal upset, seizures
Is Amantidine affordable?
NO
Licensing & directions for use of amantidine?
- Use in association with other analgesic drugs
- In EU not licensed anymore for veterinary use
What is Tramadol ? (physiological)
- Weak mu-receptor agonist
- Weak alpha 2 agonist action
- Inhibitor of norepinephrine & serotonin reuptake in the CNS – descending inhibitory
pathways
Describe USE of Tramadol?
- Active metabolite minimal in dogs & cats after oral administration
- Analgesia???
- Serotonin Syndrome risk
- Vomiting, Drowsiness
For Case of OA dog - how can we do WEIGHT management?
To reduce weight on weight- bearing joints
Adipokines (i.e., leptins…)
Reduce risk of other comorbidities
- Diet (prescription diet vs low kcal diet)
- Low calories treats
- Exercise
Supplements /adjuvants for OA case?
- GLucosamine
- Chondroitin
- Green lipped mussel extract
- Fish oils
What non-pharmacological therapies can be considered for pain management?
- Acupuncture
- Physiotherapy
- Transcutaneous electrical nerve stim (TENS)
Describe Acupuncture
- MOA?
- Endorphin release
- Wound healing
- Immuno-modulation
- Modulation of descending inhibitory pathways
- Gate Control Theory
How to use Acupuncture?
- In association with parhaC tx
- Might help to dec amount of analgesic drugs needed
- Older / sick patients
What does physiotherapy involve?
Laser therapy
TENS
Passive Range of Motion
Massage
Hydrotherapy
Underwater Treadmilll
Hot & Cold therapy
Describe use of LASER?
LASER (Light Amplification by Stimulated Emission of Radiation) therapy
- Red-infrared laser light on tissues
- Photochemical effect
Describe Transcutaneous electrical nerve stimulation (TENS) ?
- Low-voltage electric currents to treat pain & inflammation
- Gate control theory
- Endorphins release
