Antipyretic for High Fever
For adults with high fever, use paracetamol (acetaminophen) 1000 mg orally every 4-6 hours (maximum 4 g/day) as first-line therapy, prioritizing symptomatic relief and patient comfort rather than temperature reduction itself. 1, 2
Adults
First-Line Treatment
- Paracetamol (acetaminophen) is the preferred antipyretic due to its excellent safety profile, superior cardiovascular safety compared to NSAIDs, and no increased gastrointestinal complications 2
- Standard dosing: 1000 mg orally every 4-6 hours, maximum 4 g/day 1, 2
- Ibuprofen is an acceptable alternative for fever and myalgias, though paracetamol is preferred 3
Critical Dosing Adjustments
- Reduce dose in hepatic insufficiency or history of alcohol abuse 1, 2
- Absolutely contraindicated in acute liver failure 1, 2
- No dose adjustment needed for mild-to-moderate renal or hepatic failure 4
- Patients with chronic liver disease can safely use paracetamol at recommended doses, as cytochrome P-450 activity is not increased and glutathione stores remain adequate 5
Route of Administration
- All patients capable of oral intake should receive oral paracetamol 2
- IV paracetamol is preferable when IV access exists for patients unable to take oral medications (persistent vomiting, altered mental status, NPO status) 2
- Avoid IM route due to injection site pain, tissue trauma, and risk of intramuscular hematoma (especially in anticoagulated patients) 2
Children
Age-Specific Approach
Children under 16 years: Aspirin is absolutely contraindicated due to Reye's syndrome risk 3
Mild Fever (Coughs and mild fevers)
High Fever (>38.5°C) with cough or influenza-like symptoms
- Children under 1 year must be seen by a GP 3
- Children 1-7 years should be seen by nurse or GP 3
- Children ≥7 years may be seen by community health professional 3
- Provide advice on antipyretics and fluids 3
High-Risk Children (>38.5°C plus chronic disease or concerning features)
- Must be assessed by GP or A&E department 3
- Concerning features include: breathing difficulties, severe earache, vomiting >24 hours, drowsiness 3
- Treat with antipyretics, fluids, and consider antibiotics 3
Dosing Considerations in Children
- Alternating acetaminophen (12.5 mg/kg per dose) and ibuprofen (5 mg/kg per dose) every 4 hours is more effective than monotherapy in reducing fever, stress, and absenteeism 6
- However, monotherapy with either agent is acceptable for routine fever management 4, 7
Critical Clinical Principles
When NOT to Treat Fever Aggressively
- Antipyretics should be used for symptomatic relief and comfort, NOT routinely to reduce temperature 1, 2, 8
- Fever is a protective physiological response; suppression does not improve mortality or clinical outcomes 1
- Meta-analysis of 13 RCTs (n=1,963) showed no improvement in 28-day mortality, hospital mortality, or shock reversal with fever management 2, 8
When to Investigate Further
- Never delay identification and treatment of underlying infection while focusing on temperature control 1
- Obtain chest radiograph for any ICU patient with new fever (pneumonia is most common cause) 1, 8
- Blood cultures before antibiotics when fever occurs with elevated neutrophils 1, 8
- For post-surgical patients, perform CT imaging if fever persists beyond several days without identified cause 1, 8
Physical Cooling Methods
- Avoid routine physical cooling (tepid sponging, fanning) as they cause discomfort without improving outcomes 2
- Cooling devices should only be used for refractory fevers unresponsive to antipyretics 1, 2
Common Pitfalls to Avoid
- Do not use unreliable temperature measurement methods (tympanic, temporal) for clinical decisions 1
- Persistent fever alone in a stable patient is rarely an indication to alter antibiotics 1, 8
- Antipyretics do NOT prevent febrile seizure recurrence in children 3, 2
- In COVID-19, prefer paracetamol over NSAIDs until more evidence available; stop NSAIDs in severe COVID-19 with organ injury 2, 8