Analgesia 💊
Comprehensive guide to pain management and analgesia. WHO pain ladder, opioid prescribing, drug reference table, and pain assessment for NCHDs.
🧠 Understanding Pain
- Assess pain severity (mild / moderate / severe)
- Use patient’s self-report, visual analogue scale, or behavioural cues
- Identify type: nociceptive (somatic/visceral) vs. neuropathic
- Treat underlying cause when possible
📈 WHO Pain Ladder
- Step 1 – Mild Pain: Paracetamol ± NSAIDs
- Step 2 – Moderate Pain: Add weak opioid (e.g. codeine, tramadol)
- Step 3 – Severe Pain: Switch to strong opioids (e.g. morphine, oxycodone)
- Adjuvants: Consider for neuropathic pain (e.g. amitriptyline, gabapentin)
💊 Medication Guide
- See full table below for common analgesics and their dosing
- Paracetamol: Safe in most patients. Caution in liver disease.
- Ibuprofen: Avoid in AKI, GI bleed, asthma. Ensure PPI with NSAIDs.
- Codeine: Causes constipation, drowsiness.
- Tramadol: Watch for delirium, serotonin syndrome.
- Morphine (oral): Titrate to pain. Adjust for renal function.
- Oxycodone: Preferred in renal impairment.
- Amitriptyline: 10–25 mg nocte for neuropathic pain. Sedating.
📋 Practical Prescribing Tips
- Always prescribe laxatives with opioids (e.g. Senna, Lactulose)
- For elderly: start low, go slow — avoid long-acting opioids initially
- Consider co-analgesia early: paracetamol + NSAID or weak opioid
- Document pain score, response, and side effects
⚠️ Special Considerations
- Renal impairment: Avoid NSAIDs; dose-reduce or avoid morphine
- Liver disease: Adjust paracetamol dose, avoid co-codamol
- Delirium risk: Avoid tramadol, amitriptyline in older adults
- Opioid-naive vs. tolerant: Always confirm prior use before prescribing
- Palliative care: May require stepwise titration and breakthrough doses
📌 Common Mistakes to Avoid
- Underprescribing (esp. in postop or fracture pain)
- Forgetting PRN doses when regular analgesia is started
- Forgetting laxatives with opioids
- Forgetting PPI with NSAIDs in at-risk patients
- Not reassessing or escalating appropriately
🔗 Related Tools
WHO Pain Ladder - Analgesia Guide
Stepwise approach to pain management
| Drug | Dose | Frequency | Route | Notes |
|---|---|---|---|---|
| Step 1: Non-opioids (Mild Pain) | ||||
| Paracetamol | 1g | QDS | PO / PR / IV | Caution in liver disease. |
| Ibuprofen | 400mg | TDS | PO | Avoid in AKI, asthma, PUD. Ensure PPI with NSAIDs |
| Diclofenac | 50mg | TDS | PO / PR / IM | Avoid in cardiac disease. Ensure PPI with NSAIDs |
| Step 2: Weak opioids (Moderate Pain) | ||||
| Codeine | 30mg | QDS | PO | May cause constipation |
| Solpadeine | 2 tabs | QDS | PO | Contains 8mg codeine |
| Solpadol | 2 tabs | QDS | PO | Contains 30mg codeine |
| Step 3: Strong opioids (Severe Pain) | ||||
| Morphine (IV/SC/PO) | 2.5–10mg | 4–6 hourly | IV / SC / PO | Max 30mg/day initially |
| Oramorph | 10–20mg | 4 hourly | PO | Use in breakthrough pain |
| Oxycodone (Oxynorm) | 5mg | 4–6 hourly | PO | Breakthrough pain |
| Oxycodone (Oxycontin) | 5–10mg | BD | PO | Slow-release; potent |
| Fentanyl Patch | 12mcg/hr | 72 hrly | Transdermal | Chronic stable pain only |
| Adjuvant Analgesics | ||||
| Gabapentin | 300–900mg | TDS (titrated) | PO | Neuropathic pain |
| Pregabalin | 75mg | BD | PO | Neuropathic pain |
| Carbamazepine | 100mg | BD | PO | Trigeminal neuralgia |
| Lidocaine Patch | 12 hr on/off | Daily | Topical | Max 3/day |
| Hyoscine Butylbromide | 20mg | QDS | PO / IV / IM | For colicky pain |
Step 1: Non-opioids (Mild Pain)
Paracetamol
PO / PR / IVDose:1g
Frequency:QDS
Notes: Caution in liver disease.
Ibuprofen
PODose:400mg
Frequency:TDS
Notes: Avoid in AKI, asthma, PUD. Ensure PPI with NSAIDs
Diclofenac
PO / PR / IMDose:50mg
Frequency:TDS
Notes: Avoid in cardiac disease. Ensure PPI with NSAIDs
Step 2: Weak opioids (Moderate Pain)
Codeine
PODose:30mg
Frequency:QDS
Notes: May cause constipation
Solpadeine
PODose:2 tabs
Frequency:QDS
Notes: Contains 8mg codeine
Solpadol
PODose:2 tabs
Frequency:QDS
Notes: Contains 30mg codeine
Step 3: Strong opioids (Severe Pain)
Morphine (IV/SC/PO)
IV / SC / PODose:2.5–10mg
Frequency:4–6 hourly
Notes: Max 30mg/day initially
Oramorph
PODose:10–20mg
Frequency:4 hourly
Notes: Use in breakthrough pain
Oxycodone (Oxynorm)
PODose:5mg
Frequency:4–6 hourly
Notes: Breakthrough pain
Oxycodone (Oxycontin)
PODose:5–10mg
Frequency:BD
Notes: Slow-release; potent
Fentanyl Patch
TransdermalDose:12mcg/hr
Frequency:72 hrly
Notes: Chronic stable pain only
Adjuvant Analgesics
Gabapentin
PODose:300–900mg
Frequency:TDS (titrated)
Notes: Neuropathic pain
Pregabalin
PODose:75mg
Frequency:BD
Notes: Neuropathic pain
Carbamazepine
PODose:100mg
Frequency:BD
Notes: Trigeminal neuralgia
Lidocaine Patch
TopicalDose:12 hr on/off
Frequency:Daily
Notes: Max 3/day
Hyoscine Butylbromide
PO / IV / IMDose:20mg
Frequency:QDS
Notes: For colicky pain