Pain/Palliative Care Flashcards
What principles do WHO follow in pain prescription?
- Oral admin when possible
- Analgesia at regular intervals
- Prescribe according to pain intensity
- Adapt dosing to the individual
- Patient centred decision making
What is step 1 of the WHO ladder?
Non-opioids - paracetamol, NSAIDS
What is step 2 of the WHO ladder?
Weak opioids - dihydrocodeine, codeine, tramadol
What is step 3 of the WHO ladder?
Strong opioids - Hydromoprhine, morphine, fentanyl, oxycodone, diamorphine
What is step 4 of the WHO ladder?
Other - nerve block, epidural, PCA pump, spinal stimulation
What adjuvants can be used in the WHO ladder for:
a) raised ICP?
b) neuropathic pain?
c) cramp?
d) bone pain?
e) bowel spasm?
a) corticosteroids
b) pregablin, gabapentin, antidepressants, anticonvulsants
c) muscle relaxants
d) bisphosphonates
e) antispasmodics (hyoscine butylbromide)
How does paracetamol work?
Unknown, possibly COX2 inhibition
What are the indications, contraindications and side effects of paracetamol?
I: First line pain management
CI: None
SE: None
What is the standard dose of paracetamol?
1g QDS, max 4g
How do NSAIDS work?
Selective inhibition of COX 1 or COX2 and therefore prostaglandin syntehsis
What is the function of COX1?
Carries out routine physiological functions
What is the function of COX2?
Induced by pain and inflammation
Why do we not just use COX2 inhibitors then?
Although the are more specific, they have cardiovascular side effects
What are the indications, contraindications and side effects of NSAIDS?
I: inflammatory pain
CI: GI symptoms, renal failure, coagulation disorders, caution with HF
SE: gastric ulcer, bleeding, headaches, HTN
How does codeine phosphate work?
Metabolised to morphine by CYP2D6
What are the indications, contraindications and side effects of codeine?
I: Mild-moderate pain 1st line
CI: Raised ICP, bronchial asthma, severe respiratorry depression
SE: Constipation, nausea
What is the dose of codeine?
20-60mg QDS (PO/PR/IM) - not IV as could cause anaphylaxis
How does tramadol work?
Synthetic opioids with multiple active metabolites
What are the indications, contraindications and side effects of tramadol?
I: Chronic pain, after bowel surgery
CI: Renal/liver failure, raised ICP, severe resp depression, elderly
SE: (opiate SEs) N&V, drowsiness, resp depression, pruritus, hallucinations, urinary retention, pinpoint pupils, risk of serotonin syndrome
What is serotonin syndrome?
High body temp, agitation, hyperreflexia, tremor, sweating and dilated pupils.
This occurs when two or more serotonergic drugs are given at the same time
What is the dose of tramadol?
50-100mg QDS (PO/IV)
What are the indications for dihydrocodeine?
Moderate-severe pain, coughing, SOB
What is the effect of erythromycin on opiods?
Increases effect (enzyme inhibitor)
What is the effect of rifampicin and anticonvulsants on opioids?
Decreases effect (enzyme inducer)
What are the indications for morphine?
Severe acute pain and chronic pain
How does morphine work?
Acts on mu opioid receptors in the CNS
What are the side effects of opiates?
Respiratory dperession Sedation Euphoria Pupil constriction Nausea and vomiting Constipation Pruritus Hypotension Bronchospasm Urinary retention
What are the signs of opiate toxicity?
Myoclonic jerks Pinpoint pupils Hallucinations Decreased RR Confusion
(ensure this isn’t bowel obstruction/hypercalcermia)
How is opiate toxicity managed?
Reduce opiate dose by 30-50% and check renal function Switch to different opioids If severe (RR<8, o2<90) give NALOXONE
How do you prescribe an opiate
- Start at 20-30mg daily if no previous opiod or 40-60mg if previous opiod
- Titrate up and review regularly (caution in elderly/frail/renal)
- Dose immediate release every 4hr (oramorph) OR modified release every 12hr (zomorph)
- Always prescribe PRN alongside this for breakthrough pain
- If immediate release, convert to modified release when safe
- If pt keeps using PRN dose, review meds
How much should a dose for breakthrough pain be?
1/6th - 1/10th of the TOTAL regular dose in 24h
How do you switch from immediate release morphine to modified release?
Add up total morphine and divide by 2
If modified release morphine isnt given adequate control, how do you give more?
Keep titrating the dose up but dont increase by over 50%
Which pain med should never be used for dose titration or acute pain?
Fentanyl
What is the 1st line drug for neuropathic pain?
Pregablin + amitriptylline
What is the 2nd line drug for neuropathic pain?
Duloxetine (SNRI)
What is 3rd line for neuropathic pain?
Gabapentin, ketamine or lidocaine patches
What should be prescribed at EoL for pain and breathlessness for a patient with
a) eGFR>30
b) eGFR<30
a) 2.5mg morphine SC every hour
b) 100micrograms alfentanil SC every hour
What should be prescribe at EoL for nausea and vomiting for a patient with
a) eGFR>30
b) eGFR<30
a) 50mg cyclizine SC every 8 hours
b) 1mg haloperidol SC every 4 hours
What should be prescribe at EoL for agitation for a patient with
a) eGFR>30
b) eGFR<30
ALL - 2.5mg midazolam SC every hour
What should be prescribed at EoL for excess secretions for a patient with
a) eGFR>30
b) eGFR<30
a) 400micrograms hyoscine hydrobromide SC every hour
b) 20mg hyoscine butylbromide SC every hour
How do you convert oral opiod dose to palliative SC continuous syringe driver dose?
- Add up total oral dose in 24hr (PRN +regular)
- Divide by 2 to calculate dose
- Divide by 6 to calculate PRN
- Start syringe driver 4hrs before next oral dose is due, then discontinue it
