Promethazine For Children Under 2 Years Old

In our latest question and answer, the pharmacist discusses the use of promethazine in children under 2 years old.


What is the allowed dosage of promethazine for 19-month-old child?

Asked by Vijay On Mar 27, 2019

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Mar 27, 2019
Vector Of Medicine Syrup Bottle WIth Spoon WIth Text - Promethazine For Children


The use of promethazine in children under two years of age isn't approved by the FDA (Food and Drug Administration). It used to be prescribed to infants and children under two years old but was linked to respiratory depression and SIDS (sudden infant death syndrome).[1]

Promethazine In Children

Current guidelines on the use of promethazine state that use in children under two years old is contraindicated and the prescribing information for the drug contains a black box warning regarding the risk of respiratory depression in this age group.

Per the prescribing information:[2]

Phenergan [promethazine] should not be used in pediatric patients less than 2 years of age because of the potential for fatal respiratory depression. Postmarketing cases of respiratory depression, including fatalities, have been reported with the use of Phenergan [promethazine] in pediatric patients less than 2 years of age.

Dosing in children over two years old is weight-based, and depends on what it is being used for.

For the prevention of motion sickness:[3]

  • 0.25 to 0.5 mg/kg/dose given 30 minutes to 2 hours before travel and every six to twelve hours as needed. The maximum amount per dose is 25 mg. Most sources recommend using the lowest dose possible and should be reserved only for severe cases of motion sickness.

For the treatment of postoperative nausea/vomiting:[4]

  • 0.25 to 1 mg/kg/dose every four to six hours as needed, with a maximum dose of 25 mg.

Additional Information

In your question, you inquired about the use of promethazine in a 19-month-old child.

As described above, it is not indicated by the FDA to be used in that age group due to the risk of respiratory depression.

Having said that, everyone's medical situation is different and there certainly could be extenuating circumstances that make prescribing promethazine 'off-label' the most appropriate therapy choice for your child.

Be sure to speak with your doctor about the risks and benefits of this particular therapy.


Promethazine is contraindicated in children less than 2 years old due to the risk of respiratory depression.

  1. ^ Inappropriate prescribing of promethazine in infants. PubMed
  2. ^ Promethazine Prescribing Information
  3. ^ Travel Medicine, 3rd Edition. ScienceDirect
  4. ^ Elsevier ClinicalKey: Promethazine Monograph

About the Pharmacist

Dr. Brian Staiger Pharm.D

Dr. Brian Staiger is a licensed pharmacist in New York State and the founder of He graduated from the University At Buffalo with a Doctor of Pharmacy degree in 2010. He has been featured in numerous publications including the Huffington Post as well as a variety of health and pharmacy-related blogs. Please feel free to reach out to him directly if you have any inquiries or want to connect! He's answered thousands of medication and pharmacy-related questions and he's ready to answer yours! Office: 716-389-3076

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