What is the recommended dosage of Benadryl (diphenhydramine) for a 6-month-old infant?

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From the Guidelines

Benadryl is not recommended for infants 6 months of age due to the high risk of side effects and toxicity. The FDA and pediatric medical organizations advise against giving Benadryl to children under 2 years old unless specifically directed by a physician 1. Infants this young are particularly vulnerable to the medication's side effects, which can include paradoxical excitation, seizures, respiratory depression, and in severe cases, even death.

Key Considerations

  • Their immature liver and kidneys cannot metabolize and eliminate the drug effectively, increasing the risk of toxicity.
  • Dosing for such young children is difficult to calculate safely, as evidenced by the varying dosage recommendations for infants under 6 months of age, such as 1–2 mg/kg IV or 4 mg/kg IM 1. If your infant is experiencing allergy symptoms, congestion, or sleep issues, consult your pediatrician immediately for age-appropriate treatments. They may recommend safer alternatives specifically formulated for infants or non-medication approaches to address your baby's symptoms.

From the FDA Drug Label

• do not take more than 6 doses in 24 hours agedose Adults and children over 12 years of age10 mL (25 mg) to 20 mL (50 mg) Children 6 to under 12 years of age10 mL (25 mg) Children under 6 years of ageDo not use

The recommended dosage of Benadryl (diphenhydramine) for a 6-month-old infant is: Do not use. 2

From the Research

Dosage of Benadryl for a 6-month-old Infant

  • There is no specific recommended dosage of Benadryl (diphenhydramine) for a 6-month-old infant provided in the available studies 3, 4, 5, 6, 7.
  • The studies suggest that diphenhydramine has many side effects, including sedation and risk of toxicity in overdose, and that second-generation antihistamines are a safer alternative 3, 4, 5, 6, 7.
  • It is recommended to use second-generation antihistamines instead of diphenhydramine due to their similar efficacy and fewer adverse effects 4, 5, 6, 7.
  • The American Academy of Pediatrics and other medical organizations do not recommend the use of diphenhydramine in infants under 12 months old, but this information is not provided in the available studies.

Alternatives to Benadryl

  • Second-generation antihistamines, such as loratadine and cetirizine, are available and have been shown to be safer and more effective than diphenhydramine 5, 6, 7.
  • These alternatives may be considered for the treatment of allergic reactions in infants, but it is essential to consult a healthcare professional before administering any medication to a 6-month-old infant.

Important Considerations

  • Diphenhydramine can impair psychomotor performance and cognitive function, and its use is not recommended in children and older adults due to the high risk of adverse effects 3, 4, 5, 6.
  • The use of diphenhydramine in infants and young children should be avoided due to the risk of overdose and toxicity 3, 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Diphenhydramine: Time to Move on?

The journal of allergy and clinical immunology. In practice, 2022

Research

Diphenhydramine: It is time to say a final goodbye.

The World Allergy Organization journal, 2025

Research

The effects of antihistamines on cognition and performance.

The Journal of allergy and clinical immunology, 2000

Research

Evidence-based use of antihistamines for treatment of allergic conditions.

Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology, 2023

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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