Use of analgesics in practice part 1

Question 1

What factors influence the selection of analgesics?

Answer 1

Type, location, frequency, severity, and duration of pain
Medication and medical history
Social history (alcohol, drugs)
Patient factors (age, pregnancy)
Side effects, route, contraindications
Guidelines (WHO, NICE)

Question 2

What is the WHO pain ladder and its purpose?

Answer 2

A guideline for stepwise pain treatment, initially for cancer but applicable to acute/chronic pain (not for neuropathic or chronic primary pain)

Question 3

What are the steps of the WHO pain ladder?

Answer 3

Step 1: Non-opioid +/- adjuvant
Step 2: Opioid for mild/moderate pain +/- adjuvant
Step 3: Opioid for moderate/severe pain +/- non-opioid +/- adjuvant

Question 4

When should analgesics be continued according to WHO pain ladder principles?

Answer 4

If there is ongoing need, improved pain/function, minimal side effects, and benefits outweigh risks

Question 5

What are adjuvants in pain management?

Answer 5

Drugs like antidepressants, anticonvulsants, anxiolytics, corticosteroids used with analgesics to enhance pain control

Question 6

Why is paracetamol widely used?

Answer 6

Safe for most populations (children, pregnant/breastfeeding women)
Does not cause GI upset or bleeding like NSAIDs

Question 7

What is the typical adult dosage of paracetamol?

Answer 7

500mg–1g every 4–6 hours
Maximum 4g/day

Question 8

What are the OTC sale limits for paracetamol?

Answer 8

Up to 32 tablets OTC
Pharmacists may sell up to 100 tablets in justifiable circumstances

Question 9

What are side effects and risks associated with paracetamol?

Answer 9

Rare side effects: rashes, abnormal liver function
Risk of fatal liver damage in overdose or high-risk patients (e.g. alcohol use, liver disease)

Question 10

What dose of paracetamol is considered toxic?

Answer 10

Above 75 mg/kg

Question 11

What are early signs of paracetamol poisoning?

Answer 11

Emotional distress, anxiety

Question 12

How is paracetamol overdose managed in the UK?

Answer 12

IV N-acetylcysteine (Parvolex) is preferred
Methionine if Parvolex unavailable
Activated charcoal within 1 hour of overdose

Question 13

How does N-acetylcysteine (NAC) work?

Answer 13

Reduces liver toxicity by inactivating NAPQI
Acts as glutathione precursor

Question 14

When should NAC be administered?

Answer 14

If plasma paracetamol levels are above treatment line or if ALT/INR is abnormal
If ingestion time is unknown, treat as precaution