The drug atlas
Child Health/Analgesia, antipyresis & aspirin (paeds)

Paediatric analgesia & aspirin

also: paracetamol child · ibuprofen child · NSAID children · aspirin Reye Kawasaki

Overview

Antipyretics/analgesics in children, and the aspirin paradox: contraindicated for Reye syndrome — EXCEPT in Kawasaki disease, the one place children do get aspirin.

Mechanism

Paracetamol: central COX inhibition / poorly understood — antipyretic + analgesic, NOT anti-inflammatory. NSAIDs (ibuprofen): inhibit COX → ↓prostaglandins → anti-inflammatory, analgesic, antipyretic — and the SAME prostaglandin inhibition is why an NSAID closes a PDA in a neonate. Aspirin: irreversible COX inhibition; in children it is linked to Reye syndrome (encephalopathy + fatty liver) during viral illness, hence the under-16 ban — but Kawasaki disease is the deliberate exception.

Indications

  • Fever / pain (paracetamol, ibuprofen)
  • Kawasaki disease (aspirin — the exception)
  • NSAID also used to medically CLOSE a patent ductus (see Ductus arteriosus card)

The agents

Paracetamolantipyretic/analgesic

weight-based

First-line; safe; overdose → hepatotoxicity (NAC).

IbuprofenNSAID

weight-based, with food

Avoid in dehydration/shock (renal) and caution in chickenpox/varicella (necrotising soft-tissue infection risk).

Aspirinsalicylate

CONTRAINDICATED <16 (Reye) EXCEPT Kawasaki disease — high-dose (anti-inflammatory) acute, then low-dose (antiplatelet).

Adverse effects

Aspirin → Reye syndrome in childrenserious

Encephalopathy + hepatic failure during/after a viral illness — the reason for the under-16 ban.

Ibuprofen: GI upset, renal impairment (esp. dehydrated child)common
Paracetamol overdose hepatotoxicityserious
Do NOT routinely alternate/combine paracetamol + ibuprofencommon

Use one; only switch/combine if distressed and not responding (NICE NG143).

Cautions & contraindications

Aspirin in children <16paediatric

Reye syndrome — UNLESS Kawasaki disease (or other specific specialist indication).

Ibuprofen in significant dehydration / renal impairment / active GI bleedpaediatric
Ibuprofen caution in chickenpoxpaediatric

Possible link to severe soft-tissue infection.

Interactions

  • NSAID + dehydration → AKI

Monitoring & kinetics

Fever response, hydration; in Kawasaki: echo for coronary aneurysms

Weight-based oral dosing; ibuprofen with food.

Source: NICE NG143 — Fever in under 5s · BNF for Children — Analgesics