How to Find the Right Benadryl Dosage for Kids (and Use It Safely)

Spring is peak allergy season, with trees and plants finally flowering after the winter months. And while these buds are a welcome sight, your kids may struggle with some not-so-pleasant seasonal allergy symptoms. Benadryl can relieve your child's allergy symptoms, but it can be extremely dangerous for young children, especially when not given in the proper dose. Here's everything parents need to know about Benadryl for kids.

What Is Benadryl?

"Diphenhydramine (commonly known by the brand name Benadryl) belongs to a class of medications called antihistamines that block the chemical histamine's activity in the respiratory tract, gastrointestinal tract, and the blood vessels," says Jeffrey Tan, M.D., a pediatrician at Stanford Children's Health with Peninsula Pediatric Medical Group.

And it's these histamines that are responsible for allergy symptoms. "Histamines are naturally occurring substances in the body that can cause common allergy-type symptoms, such as hives, itching, and nasal congestion, or a cough related to allergies," says Kristi Redlich, M.D., a pediatrician with Northwestern Medicine Huntley Hospital. "The antihistamine medicines block the receptors for histamines, thereby preventing their action and the symptoms."

Risks of Benadryl for Babies and Toddlers

"Benadryl is not recommended for use in children under 2 years of age unless it's specifically directed by a doctor," says Dr. Redlich. The Food and Drug Administration released a warning in 2007 that children under 2 should not be given antihistamines, as they can cause life-threatening side effects, including convulsions, rapid heart rates, and decreased levels of consciousness.

The warning was issued after an estimated 1,519 children younger than 2 were treated in U.S. emergency departments for adverse events, including overdoses, associated with cough and cold medications from 2004 to 2005.

"It is very important to follow dosing guidelines when giving Benadryl to kids. Giving incorrect doses can be quite dangerous and even fatal," says Dr. Redlich. Unfortunately, many deaths have been associated with Benadryl overdoses in children due to improper dosing, including 7-month-old Abigail "Abi" Lobisch in Hawaii, who was given a lethal dose of Benadryl by her babysitter.

How to Find the Right Benadryl Dosage for Kids

Your child's weight will determine the proper and safe Benadryl dose for them. "I like to have parents refer to a dosing chart," says Dr. Redlich who recommends following the dosage guidelines from the American Academy of Pediatrics (AAP). "If there are any questions or a parent is not sure, I recommend they double check with their pediatrician prior to giving the medication."

When determining the appropriate dosage for your child, it's important to also note how often it's safe to give your child the medication. The AAP guidelines allow for giving the medication every six hours (as needed) and warn parents not to give more than four doses in a 24-hour period.

Side Effects of Benadryl Parents Should Know

Though Benadryl is generally considered safe for kids 2 years and older when given in the correct dose for their weight, there are side effects and contraindications to be aware of.

"Benadryl can cause drowsiness as well as mouth dryness, thickened sputum (mucus), and can also cause paradoxical excitation (hyperactivity) in some young children," says Dr. Tan. "It should be used with caution in children who are on other medications that cause drowsiness and in children with asthma. Although not common in children, parents should check with their physician before using Benadryl in kids with glaucoma, liver disease, or cardiovascular disease."

How to Avoid Overdose

It's OK to give kids of the appropriate age Benadryl to ease their allergy symptoms, but you should aim to use it only temporarily.

"Benadryl is intended to mainly be used for short-term relief of allergy symptoms, and it is not recommended to use it as a long-term allergy medication," says Dr. Redlich. "There are other types of antihistamines that would be preferable for long-term use because they have fewer significant side effects, like Claritin and Zyrtec."

In fact, many allergists have started recommending Zyrtec because as a second-generation antihistamine, it has fewer side effects and lasts longer than first-generation antihistamines like Benadryl, adds Dr. Tan.

Options like Claritin (loratadine) and Zyrtec (cetirizine) are likely safe for most children 2 and up, but parents should always check with their doctors before using any new medications.

Using Benadryl as a Sleep Aid for Kids

Benadryl should not be used for sleep aid or sedation. "Benadryl is never recommended to be used as a sleep aid for children, and it is also never recommended for use on long trips (plane or car rides) to keep kids calm," says Dr. Redlich.

Benadryl is known to cause drowsiness, which is why many think that it can be a safe sleep aid: If it's safe to use for allergies, why wouldn't it be safe for sleep? It turns out that Benadryl affects REM sleep by keeping a person in a light sleep state and preventing them from entering deeper, more restful, and restorative stages of sleep. Researchers theorize that this lack of restorative sleep may explain the link between long-term Benadryl use and a higher risk of dementia.

Babies and toddlers who struggle to go to sleep or stay asleep should not be given Benadryl as a sleep aid. Instead, parents can look closer at their bedtime and naptime routines to find better ways to help their little ones catch some zzz's.

The Bottom Line

"As with all prescription and non-prescription medication, Benadryl should only be used when needed with attention to proper dosing and possible side effects," says Dr. Tan.