Disclaimer to the On-line Edition
This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual.



  • acetaminophen is used as an analgesic (for mild pain) and as an antipyretic (for fever)


  • significantly lowers the frequency and severity of common adverse reactions (fever, fussiness, crying, anorexia) following DPTP vaccinations in infants 2 to 6 months of age

  • appears to produce analgesia through inhibition of prostaglandin synthesis in both the CNS and the periphery

  • acetaminophen's antipyretic effect is related to inhibition of prostaglandin synthesis and release. Prostaglandins mediate the effect of endogenous pyrogen in the hypothalamus

Side Effects

  • relatively free of adverse effects when given as indicated above


  • regular dosing of acetaminophen can mask manifestations of infection (eg. fever, fussiness, crying, irritability) possibly causing a delay in treatment. Caregivers should monitor infants with extra care during the period when acetaminophen is given

  • acetaminophen liquid is available in different strengths. Be sure to check the concentration when administering this medication



    • 15 mg/kg po or pr (per rectum)
      (oral administration is preferable since rectal absorption is erratic)

    • give first dose just before (ie. 10 to 15 minutes) vaccination; then q4h x 3 doses for a total dose of 60 mg/kg

      MAXIMUM DAILY DOSE: 65 mg/kg


    • 10 to 15 mg/kg/dose po or pr (per rectum), usually given q4-6h prn
      (oral administration is preferable since rectal absorption is erratic)

      MAXIMUM DAILY DOSE: 65 mg/kg


  • Drops 80 mg/mL
  • Suppository 120 mg


  1. McEvoy G K (ed): AHFS Drug Information, American Society of Hospital Pharmacists, 1991.
  2. Uhari M, Hietala J and Viljanen MK: Effect of prophylactic acetaminophen administration on relation to DTP vaccination, Acta Paediatr Scand 1988; 77: 747-751.
  3. Ipp MM, Gold R, Greenburg S et al: Acetaminophen prophylaxis of adverse reactions following vaccination of infants with diphtheria-pertussis-tetanus toxoids-polio vaccine, Pediatr Infec Dis J 1987; 6: 721-725.
  4. Lewis K, Cherry JD, Sachs MH et al: The effect of prophylactic acetaminophen administration on reactions to DTP vaccination, AJDC 1988; 142: 62-65.
  5. Milan EM and McFeely EJ: Memory Bank for Neonatal Drugs, 1990, Williams and Wilkins, Baltimore.

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