What are the recommended doses of paracetamol (acetaminophen) for adults and children?

Paracetamol (Acetaminophen) Dosing Guidelines

Adult Dosing

For adults, the standard dose is 650-1000 mg every 4-6 hours, with a maximum daily limit of 4000 mg, though a more conservative limit of 3000 mg per day is recommended for chronic use to reduce hepatotoxicity risk. 1

Standard Adult Dosing Parameters

• Single dose range: 650-1000 mg every 4-6 hours 1, 2
• Minimum interval between doses: 4 hours 1
• Maximum doses per day: 6 doses in 24 hours 1
• Absolute maximum daily dose: 4000 mg/day 3, 1, 4
• Recommended maximum for chronic use: 3000 mg/day 1

Critical Safety Considerations for Adults

• Patients must be explicitly counseled to avoid all other acetaminophen-containing products, including over-the-counter cold remedies, sleep aids, and opioid combination products 1
• Prescription combination products are limited to ≤325 mg acetaminophen per dosage unit 1
• Repeated supratherapeutic ingestions (doses just above therapeutic range) carry a worse prognosis than acute single overdoses, with approximately 30% of acetaminophen overdose admissions involving repeated supratherapeutic ingestions 1

Special Adult Populations

Elderly Patients (≥60 years)

• Maximum daily dose should be reduced to 3000 mg per day or less 1
• Starting dose should be at the lower end of the dosing range (325 mg per dose) for frail elderly 1
• No evidence supports routine dose reduction for all older people, but dosing should be individualized for those with decompensated cirrhosis or advanced kidney failure 5

Patients with Liver Disease

• Maximum daily dose: 2000-3000 mg per day 1
• Paracetamol is contraindicated in hepatic insufficiency 6
• Hepatotoxicity is rare among adults who use paracetamol as directed, including people with cirrhotic liver disease 5

Chronic Alcohol Users

• Maximum daily dose should be limited to 2000-3000 mg per day 1
• Patients should be advised to avoid concurrent alcohol use 1

Critically Ill Adults

• Recommended dose: 1 gram every 6 hours (IV, oral, or rectal) as an adjunct to opioids 1
• Caution: IV acetaminophen may cause hypotension in up to 50% of patients 1

Pediatric Dosing

Children and Adolescents (≥12 years)

• Dose: 650 mg every 4-6 hours 1
• Maximum: 6 doses in 24 hours, not exceeding 4000 mg total daily 1
• Alternatively: 20.3 mL (650 mg) every 4-6 hours, not to exceed 6 doses in 24 hours 2

Children Under 12 Years

• Standard oral dose: 10-15 mg/kg every 4-6 hours 1, 6
• Maximum daily dose: 60 mg/kg/day 1, 6

Age-Specific Pediatric Dosing (from FDA labeling)

• Children 6 to under 12 years: 10.15 mL (325 mg) every 4 hours, not to exceed 5 doses in 24 hours 2
• Children 4 to under 6 years: 7.5 mL (240 mg) every 4 hours, not to exceed 5 doses in 24 hours 2
• Children 2 to under 4 years: 5 mL (160 mg) every 4 hours, not to exceed 5 doses in 24 hours 2
• Children under 2 years: Consult a doctor 2

Pediatric Special Considerations

• Use an appropriate measuring device such as a 3-mL or 5-mL oral syringe for accurate measurement in infants and young children 7
• In children with hepatic impairment, doses should be reduced and intervals extended 7
• Chronic exposures greater than 140 mg/kg/day for several days carry a risk of serious liver toxicity and failure 7

Multimodal Approach for Inadequate Pain Relief

When acetaminophen alone provides insufficient pain control, add adjuvant therapies rather than exceeding the 3000 mg daily maximum. 1

Recommended Adjuvants

• Topical lidocaine patches 1
• Regional nerve blocks 1
• NSAIDs (ibuprofen 10 mg/kg every 8 hours in adolescents) 1
• In children, if acetaminophen is ineffective for fever management, ibuprofen may be considered as second-line treatment 7

Common Pitfalls to Avoid

• Failing to recognize acetaminophen in combination products leads to unintentional overdose 1
• Using multiple products simultaneously without monitoring cumulative dose can result in hepatotoxicity 1
• When using combination opioid-acetaminophen products, exercise caution to prevent excess acetaminophen dosing 7
• Overdose can result in liver and kidney failure, particularly with repeated supratherapeutic ingestions 7