Week 230 - Pain Flashcards
What three elements are typical of ‘chronic pain syndrome’?
1) fatigue (sleep disturbance - query what causes their waking)
2) depression
3) huge impact on social and family life
What type of pain are these symptoms describing:
Stinging/tingling/electric shocks/ burning pain?
Neuropathic
How is neuropathic pain pathophysiologically different to nociceptive pain?
Neuropathic = nerve damage which doesn't require nociceptor stimulation (can be stimulated by central or peripheral NS) Nociceptive = detected by nociceptors and activation of pain pathways
What sort of relief does oromorph supply?
Short-acting, fast release
Not appropriate for chronic pain
Name 4 first line pharmacological treatments for neuropathic pain?
Gabapentin
Pregabalin
Amitriptyline
Duloxetine
Name 2 second line pharmacological treatments for neuropathic pain?
Tramadol or anti-epileptics (e.g. Carbamazepine)
Which of the following are non-opioids?
Codeine Morphine Paracetamol Naproxen Tramadol Fentanyl
Gabapentin Dihydrocodeine Ibuprofen Amitriptyline Oxycodone
Paracetamol Ibuprofen Naproxen Gabapentin (for neuropathic pain / epilepsy) Amitriptyline (tricyclic AD)
What are the 3 steps on he analgesic ladder and what sort of pain is the ladder suitable for?
The WHO analgesic ladder is appropriate for nociceptive pain.
1) non-opioid +/- adjuvants
2) weak opioid + non-opioid +/- adjuvants
3) strong opioid + non-opioid +/- adjuvants
What is meant by an “adjuvant” analgesic?
A drug that was not initially intended to be used in the management of pain, but for other conditions such as depression and seizures
Give 4 different types of adjuvant analgesics
Bisphosphonates Steroids Muscle relaxants Antidepressants Anticonvulsants
Give 2 weak opioid examples
Codeine
Dihydrocodeine
Is Tramadol a weak or strong opioid?
Moderate
Give 3 examples of strong opioids
Morphine
Oxycodone
Fentanyl
How does paracetamol act
Acts as analgesic and antipyretic
Largely unknown mechanism ?COX3
Minimal anitinflammatory effect
How much IM morphine is equal to 1g IV paracetamol?
10mg
What is the antidote to paracetamol poisoning?
N-acetylcysteine (acts against metabolite N-acetyl-p-benzoquinoneimine
Who should not have paracetamol?
Virtually no groups who cannot have!
Ok for those sensitive to aspirin and NSAIDs, children and elderly
What drug is first line for treatment of Diabetic Sensory Neuropathic Pain?
Duloxetine (SSRI)
What type of plaster/cream might you add if Duloxetine wasn’t effective in diabetic sensory neuropathic pain?
Capsaicin (though can cause strong burning pain on initial use which reduces its use clinically)
Suggest some good medications for Phantom Limb Pain
Paracetamol
Tramadol
Perhaps MST
Amitriptyline to help sleep at night if worst through night
Suggest possible management for Central Post-Stroke Neuropathic Pain
Meds: 1st line gabapentin, pregabalin, Amitriptyline or Duloxetine
2nd line anti-epileptic or Tramadol
Consider electrical stimulation to strengthen muscles, nerve blocks (suprascapular is shoulder subluxation) and psysio to realign legs if circumduction /equinovarus deformity
If mixed nerve root L5/S1 and nociceptive pain and already in codeine sulphate, paracetamol and Tramadol PRN how would you manage?
Neuropathic agent: Amitriptyline or Gabapentin
Slow release opioid: Tramadol or codeine (should not be on both)
Consider nerve root block
Then physio e.g. Core strengthening and stability exercises
ONLY MAKE ONE CHANGE TO MEDS AT A TIME
What sort of plaster might you use for post-herpatic pain e.g. Shingles?
Lidocaine 5% +/- capsaicin
On for 12 hrs, off for 12 hrs
What is a common pattern for fibromyalgia (generalised pain) and how would you distinguish it from polyarthritis?
Previously high- achieving then life event which results in a loss of control
Differentiate from polyarthritis but enquire ping about location of pain, if not specifically in joints then NOT arthritis
What does NICE suggest should be ruled out with migraine sufferers before pharmacological treatment begins. Which 3 drug types should then be tried before Botox injections considered?
Ensure migraines are not caused by a current medication first Then try (in turn) beta blockers, high dose aspirin (or other NSAIDs e.g. Diclofenac Potassium / ibuprofen / naproxen) and 'Tripans' (5HT-1 agonists)
Which group of drugs are COX2-selective? What is the main advantage and disadvantage of their use over the more (not entirely selective) COX1 selective NSAIDs?
The “-coxib” meds
Advantage is reduced adverse GI effects
Disadvantage possible higher risk or MI
What is the major difference between COX1 and COX2 enzymes?
COX1 produces “house-keeping” prostaglandins e.g. PgI2 (upper GI) and PgE2 (kidney prostaglandins) which stim. mucus production and regulate gastric acid and water excretion.
COX2 produce PGs for inflammatory response stim by inflam cytokines and GFs (part of immune response)
If any risk factors for GI adverse effects with NSAID mx what should you do?
Prescribe a PPI also
Which NSAID has least thrombotic risk?
Naproxen
(By that means most balanced between not causing GI bleeds/ulcers - as aspirin and ibuprofen do and not increasing CV risks - as -coxibs do)
List 5 beneficial effects of opioids
Analgesia
Euphoria
Cough suppression
Sedation and antidiarrohoeal activity (could both potentially be adverse)
Besides opioid effects what other actions does Tramadol have therapeutically and what does this implicate in case of OD?
Stimulation of serotonin
Inhibits reuptake if noradrenaline
Naloxone only partially reverses its analgesic action
Why is diamorphine more likely to be abused than morphine?
Faster onset and shorter acting
Hence methadone used in withdrawal programmes as long acting
Which strong opioid has affinity for all 3 opioid receptor types (Mu, Delta and Kappa)?
Oxycodone
Why is buprenorphine also good in withdrawal programmes?
No euphoric effect
If strong opioid necessary which is most appropriate to start with?
Morphine (oral route whenever possible)
What adjuvants would you use with bone pain and muscle spasm?
Bone pain - bisphosphonates
Muscle spasm - baclofen
Which anti-epileptics Re appropriate for use in pain management?
Gabapentin and Carbemazepine
What would NiCE recommend over Gabapentin? Why do other groups disagree?
Pregabalin
Gabapentin is cheaper
What side effects might you get from Amitriptyline used as pain mx adjunct?
Drowsiness
Arrhythmias
Blurred vision
Dry mouth
What type of drug is ketamine? What is it used for in paeds and why might clinicians avoid its use in analgesia?
NMDA receptor antagonist
Anaesthesia in paeds
Psychotropic SEs inc: hallucinations and amnesia
What constitutes chronic pain?
Generally >3-4 months
“That which lasts longer than healing process”
