Acetaminophen

General

  • Type: Antipyretic
  • Dosage Forms: IV; PO; PR
  • Common Trade Names: Tylenol, Paracetamol

Adult Dosing

General

  • PO
    • Immediate-release
      • Regular strength: 650mg q4-6 hours
      • Extra strength: 1000mg q6 hours
    • Extended-release: 1300mg q8 hours
  • Rectal: 650mg q4-6 hours
  • IV:
    • <50 kg: 15mg/kg q6 hours or 12.5mg/kg q4 hours
    • ≥50 kg: 650mg q4 hours or 1000mg q6 hours
  • Maximum daily dose: 4g

Pediatric Dosing

  • 15mg/kg/dose q6 hours

Acetaminophen Pediatric Dosing Chart

Weight (kg) Weight (lbs) Age Dosage (mg)
3-4 6-11 0-3 mo 40
5-7 12-17 4-11 mo 80
8-10 18-23 1-2 y 120
11-15 24-35 2-3 y 160
16-21 36-47 4-5 y 240
22-26 48-59 6-8 y 320
27-32 60-71 9-10 y 400
33-43 72-95 11 y 480
Dosage can be given q6hours

Special Populations

  • Pregnancy Rating: B
  • Lactation Risk Categories: safe
  • Renal Dosing
    • Adult: CrCl 10-50: give q6h, CrCl <10: give q8h
    • Pediatric: CrCl 10-50: give q6h, CrCl <10: give q8h
  • Hepatic Dosing
    • Adult: not defined
    • Pediatric: not defined

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

Common

  • Nausea
  • Rash
  • Headache

Warnings

  • When calculating maximum daily dose consider all sources of acetaminophen
  • Be careful that the dose in milligrams and milliliters is not confused

Pharmacology

  • Half-life: 2-4 hour
  • Metabolism: Liver
  • Excretion: urine
  • Mechanism of Action:antipyretic effect via direct action on the hypothalamic heat-regulating center

See Also

References