Paeds · clinical-pharmacology-and-therapeutics
Analgesics and antipyretics
Also known as Paediatric analgesia · Paracetamol and ibuprofen dosing in children · Antipyretic use in the febrile child · WHO analgesic ladder for children · Paediatric opioid safety and codeine restriction
A fellowship approach to choosing and dosing an analgesic or antipyretic in a child: weigh the child, calculate the dose from a current paediatric formulary, cap it at the adult maximum, and combine the drug with age-appropriate comfort. Paracetamol 15 mg per kg per dose (maximum 60 mg per kg per day, adult maximum 1 g per dose and 4 g per day) and ibuprofen 5 to 10 mg per kg per dose (maximum 30 mg per kg per day, from three months and over 5 kg) cover most fever and mild-to-moderate pain. Morphine 0.1 to 0.2 mg per kg intravenously treats severe pain. Aspirin is avoided in under-16s with viral illness because of Reye syndrome, and codeine and tramadol are contraindicated in children under 12 and after tonsillectomy because CYP2D6 ultrarapid metabolisers convert a therapeutic prodrug dose into a fatal morphine overdose. Alternating paracetamol and ibuprofen is not routine: use one effective agent with a clear plan.
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- Paracetamol 15 mg per kg per dose is correct; the preventable disaster is exceeding the daily ceiling by combining cold preparations, doubling doses, or dosing on an estimated weight. The maximum is 60 mg per kg per day in a child and 4 g per day in an adult-sized adolescent.
- Aspirin is avoided in children under 16 with viral illness because of the association with Reye syndrome; use paracetamol or ibuprofen for fever and pain instead.
- Codeine and tramadol are contraindicated in children under 12 and in any child after tonsillectomy or adenoidectomy: a CYP2D6 ultrarapid metaboliser converts the prodrug to a lethal morphine overdose and obstructive-sleep-apnoea compounds the risk.
- A non-steroidal anti-inflammatory drug given to a dehydrated child can precipitate acute kidney injury: restore circulating volume first, and reserve NSAIDs for the child who is drinking and passing urine.
- A febrile child who responds to an antipyretic is not cleared of serious bacterial infection: the response is one input only, and a toxic or non-responsive child needs urgent septic work-up and source control.
- Suspected paracetamol overdose needs the time of ingestion and a four-hour level for the treatment nomogram; N-acetylcysteine is highly effective when given early and the early window is the treatable window.
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Board mappings
- Clinical Sciences — Pharmacology
- Clinical Sciences — Pharmacology 10–12
- Current 2026 PREP curriculum — Learning Objective 1.5.2: Demonstrate safe and quality use of medicines, including analgesic and antipyretic prescribing in children
- Current 2026 PREP curriculum — Learning Objective 2.2.1: Recognise, prioritise and manage an acutely ill infant, child or young person, including the febrile and the child in pain
- Renewed curriculum for first-year trainees from 2027 — Learning goal 4: Safe and effective prescribing
- Clinical Applications
- Medical Sciences
- Long Cases
- Short Cases
- 7. Patient safety, including safe prescribing
- 4. Professional skills and knowledge: Patient management
- 8. Pharmacology: Lead on the safe and effective use of medicines
- Applied Knowledge in Practice (AKP)
- Theory and Science (TAS)
- Clinical
- History
- Communication
- General Pediatrics Content Outline — Universal Task 4: Management and Treatment
- General Pediatrics Content Outline — Universal Task 7: Patient Safety and Quality Improvement
- General Pediatrics EPA 4: Writing Prescriptions
- Patient Care 5: Patient Management
- Systems-Based Practice 1: Patient Safety
- Practice-Based Learning 2: Reflects on unsafe practice and medication safety
- Medical Expert
- Pediatrics: Foundations EPA #5 — Prescribing medications safely
- Pharmacotherapeutic stewardship and safe medication use
Overview & Definition
An analgesic relieves pain, and an antipyretic lowers fever. The two jobs overlap because the same drug often does both: paracetamol and the non-steroidal anti-inflammatory drugs (NSAIDs) reduce fever by resetting the hypothalamic thermostat and ease pain by blocking prostaglandin-driven inflammation, so a single dose given for a febrile, uncomfortable child is doing two jobs at once. Morphine, by contrast, is a pure analgesic with no antipyretic action, because it works on the opioid receptor rather than on the prostaglandin pathway. The prescriber's question is therefore not "pain or fever" but "what is the problem, how heavy is it, and which agent at which dose will relieve the child safely." [2] [3]
The discipline of the topic lives in four facts. First, every dose is calculated from a measured weight in kilograms, because a child is not a fraction of an adult. Second, the calculation always stops at the adult maximum, so a large adolescent never receives more than an adult would. Third, the choice is governed by the child's age, hydration, renal and liver function, asthma and bleeding risk, and by what the drug is for. Fourth, the response is judged on the child — comfort, activity, hydration and a pain score — and not on a number on the thermometer, because a falling temperature in a toxic child can mask serious illness. [2] [9]
The unifying principle is the right drug, at the right weight-based dose, capped at the adult maximum, combined with comfort, and judged on the child. A fever that distresses a well child is treated for comfort; a fever in a toxic child is treated while the septic work-up proceeds. Pain is treated in its own right and reassessed, because undertreated pain in a pre-verbal or cognitively impaired child is a failure of care, not a kindness. The exam answer is the workflow and the safety boundaries, not the arithmetic of a single dose: weigh, calculate, cap, give, comfort, reassess. [11] [12]
References12ShowHide
- [1]De la Cruz-Mena JE, Veroniki AA, Acosta-Reyes J, et al. Short-term Dual Therapy or Mono Therapy With Acetaminophen and Ibuprofen for Fever: A Network Meta-Analysis Pediatrics, 2024.PMID 39318339
- [2]Paul IM, Walson PD Acetaminophen and ibuprofen in the treatment of pediatric fever: a narrative review Curr Med Res Opin, 2021.PMID 33966545
- [3]Rainsford KD Ibuprofen: pharmacology, efficacy and safety Inflammopharmacology, 2009.PMID 19949916
- [4]Chiew AL, Reith D, Pomerleau A, et al. Updated guidelines for the management of paracetamol poisoning in Australia and New Zealand Med J Aust, 2020.PMID 31786822
- [5]Chiew AL, Gluud C, Brok J, et al. Interventions for paracetamol (acetaminophen) overdose Cochrane Database Syst Rev, 2018.PMID 29473717
- [6]Schrör K Aspirin and Reye syndrome: a review of the evidence Paediatr Drugs, 2007.PMID 17523700
- [7]Kohler JE, Cartmill RS, Kalbfell E, et al. Continued Prescribing of Periprocedural Codeine and Tramadol to Children after a Black Box Warning J Surg Res, 2020.PMID 32693330
- [8]Robb PJ More codeine fatalities after tonsillectomy in North American children. Time to revise prescribing practice! Clin Otolaryngol, 2013.PMID 24165486
- [9]Kauffman RE, Lieh-Lai M Ibuprofen and increased morbidity in children with asthma: fact or fiction? Paediatr Drugs, 2004.PMID 15449966
- [10]Pywell A, Xyrichis A Does topical Amethocaine cream increase first-time successful cannulation in children compared with a eutectic mixture of local anaesthetics (EMLA) cream? A systematic review and meta-analysis of randomised controlled trials Emerg Med J, 2015.PMID 25351196
- [11]Pillai Riddell RR, Bucsea O, Shiff I, et al. Non-pharmacological management of infant and young child procedural pain Cochrane Database Syst Rev, 2023.PMID 37314064
- [12]Parikh JM, Amolenda P, Rutledge J, et al. An update on the safety of prescribing opioids in pediatrics Expert Opin Drug Saf, 2019.PMID 30650988