What is the recommended dose of paracetamol (acetaminophen) for fever management in an adult patient with measles, potentially complicated by pneumonia or encephalitis?

Paracetamol Dosing for Fever in Adults with Measles

For fever management in adults with measles, administer paracetamol 1000 mg (1 gram) orally every 4-6 hours as needed, with a maximum of 4 grams (4000 mg) in 24 hours. 1, 2

Standard Dosing Protocol

• The optimal single dose for adults is 1 gram (1000 mg), which provides superior analgesic and antipyretic efficacy compared to lower doses. 2
• Dosing intervals should be every 4-6 hours as needed, consistent with the drug's duration of action which typically lasts approximately 6 hours. 2
• The maximum daily dose must not exceed 4 grams (8 tablets of 500 mg) in any 24-hour period. 1, 2

Clinical Context for Measles

While paracetamol is commonly used for fever reduction, it's important to understand that:

• Fever in measles is part of the body's immune response, and paracetamol shows limited effectiveness in fever control with no important advantage over placebo in some contexts. 3
• The primary evidence-based intervention for reducing measles mortality and morbidity is vitamin A supplementation (200,000 IU for adults), not antipyretics. 4
• Measles complications including pneumonia and encephalitis occur in approximately 1 per 1000 cases, with adults at particularly high risk for encephalitis. 5

Special Considerations for Complicated Measles

If pneumonia or encephalitis develops:

• Continue standard paracetamol dosing (1000 mg every 4-6 hours, maximum 4 grams daily) for symptomatic fever relief. 1, 2
• Ensure vitamin A supplementation is administered: 200,000 IU on day 1, with a second dose on day 2 for complicated cases. 4
• Monitor for signs of severe complications requiring hospitalization, as 23% of adult measles cases require admission. 5

Critical Pitfalls to Avoid

• Do not exceed the maximum daily dose of 4 grams, as hepatotoxicity can occur even with minor overdoses. 2, 3
• Paracetamol is contraindicated in patients with hepatic insufficiency, though dosage adjustment is typically unnecessary in elderly patients or those with chronic renal insufficiency. 2
• Do not rely solely on antipyretics for measles management—vitamin A supplementation is the only intervention proven to reduce measles mortality. 4
• Carefully record all dose times to prevent inadvertent overdosing, particularly if patients are self-medicating. 6

Pharmacokinetic Considerations

• Paracetamol is rapidly absorbed with peak levels occurring within 30-60 minutes after oral administration, though absorption may be delayed by food. 7
• The plasma half-life ranges from 1.9 to 2.5 hours in healthy adults, with 85-95% excreted in urine within 24 hours. 7
• Effervescent formulations provide more rapid absorption and onset of action compared to conventional tablets. 2