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

• Acetaminophen (tylenol) toxicity
• Anemia
• Thrombocytopenia

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

• Acetaminophen (tylenol) toxicity

References

Authors

Ross Donaldson, Babak Missaghi, Andy Gausepohl, Neil Young, Daniel Ostermayer