Diphenhydramine Dosage – Benadryl

Diphenhydramine (Benadryl) Dose Table
Child’s weight (pounds) 18 25 36 54 72 lbs
Liquid 12.5 mg/ 1 teaspoon (tsp) 1/2 3/4 1 1.5 2 tsp
Liquid 12.5 mg/5 milliliters (ml) 2.5 3.75 5.0 7.5 10 ml
Chewable 12.5 mg 1 1.5 2 tablets
Tablets 25 mg ½ 1 1 tablets
Capsules 25 mg 1 1 caps

When to Use. Treatment of allergic reactions, nasal allergies, hives and itching.

Table Notes:

  • AGE LIMITS. For allergies, don’t use under 1 year of age. (Reason: it causes most babies to be sleepy). For colds, not advised at any age. (Reason: no proven benefits). They should be not be given if under 4 years old. If under 6 years, don’t give products with more than one ingredient in them. (Reason: FDA recommendations 10/2008).
  • DOSE. Find the child’s weight in the top row of the dose table. Look below the correct weight for the dose based on the product you have.
  • MEASURE the DOSE. Syringes and droppers are more accurate than teaspoons. If possible, use the syringe or dropper that comes with the medicine. If not, you can get a med syringe at drug stores. If you use a teaspoon, it should be a measuring spoon. (Reason: regular spoons are not reliable.) Keep in mind 1 level teaspoon equals 5 ml and that ½ teaspoon equals 2.5 ml.
  • ADULT DOSE. 50 mg
  • HOW OFTEN. Repeat every 6 hours as needed.
  • CHILDREN’S BENADRYL FASTMELTS. Each fastmelt tablet equals 12.5 mg. They are dosed the same as chewable tablets.

I do not routinely recommend cold medications to infants under TWENTY FOUR months of age.

I do not recommend combination medications such as Tylenol cold or Motrin cold and flu because you often will need cold medications for a longer period of time than you will need a fever reducer.

If you require a fever medication such as Tylenol (acetaminophen) or Motrin/Advil (Ibuprofen) for more than three days, please call the office.

We do not routinely recommend Tylenol for teething. If you feel that your child needs medication for comfort give it at bedtime only.

Decongestants should not be used under 6 years of age according to recent CDC and AAP guidelines.

      Reason 1: Not approved by FDA because dosage not studied in this age range

      Reason 2: Risk of dosage error causing high blood pressure.

Cold medications

Parent always ask for dosages of cough and cold medication.  Keep in mind that most OTC medication do not work.  There are some allergy medication that may help lessen some symptoms.  Please review the following information from Dr Barton Schmidt.

 This is dated material that I had previously posted on my website.

Cough and Cold Medicines

You may have noticed that all the liquid cough and cold medicines for babies and infants(the ones with droppers) have been taken off the pharmacy shelves. That’s a gooddevelopment.  First, they never worked well in children.  More importantly, they were potentially dangerous, especially for young children. Because of deaths and other adverse outcomes, in January 2008, the FDA issued a Public Health Advisory that they never be used under 2 years of age.

Cough and Cold Medicines: What Do They Do?

Antihistamines  (such as Benadryl):  No help for colds. Helpful for nasal allergies or allergic coughs caused by pollen or cat dander. Also great for hives or itchy rashes.

Diphenhydramine – Benadryl dose

Decongestants  (such as Pseudoephedrine and Phenylephrine): May help reduce nasalcongestion in some children with colds, but only lasts for a few hours and can cause elevated blood pressure and restlessness.

Dextromethorphan (DM): A cough suppressant that doesn’t do much for children.  Over 1 year of age, honey has been proven to work better (recent research).

Acetaminophen (Tylenol) and Ibuprofen (Advil): Useful for treating pain or fever.  See post on fever.

Antibiotics  : Never helpful with colds (which are caused by a virus) unless they are complicated by a secondary bacterial infection such an an ear infection, pneumonia or sinus infection.

How to Make Your Child More Comfortable with Home Remedies

Try the following home remedies to manage your child’s illness without any cough or  cold medications:

Runny Nose

: Suction or blow! And remember, when the nose turns into a faucet, it’s washing out the virus invaders.

Blocked Nose

: Use nasal washes.  Use saline nose drops or spray to loosen up the dried mucus, followed by blowingor suctioning the nose.

Do nasal washes at least 4 times per day.

Coughing or Coughing Spasms:  Use homemade medicines and warm mist.  Warm clear fluids (e.g., water or apple juice) to treat the cough (if over 1 month of age). Dosage: 1-3 teaspoons (5-15 ml) four times per day when coughing for kids under 1 year of age. Over 1 year of age, can offer unlimited amounts.  Expose to warm mist (e.g., foggy bathroom).  Honey (or corn syrup if honey not available) 1/2 to 1 tsp (2 to 5 ml) as needed as a homemade cough medicine  (if over 1 year of age)  Cough drops (or hard candy) to coat the irritated throat. (if over 6 years of age)

Increase Fluids:  Drink plenty of fluids. Staying well hydrated thins the body’s  secretions, making it easier to cough and blow the nose.

Increase Humidity:  Humidity can reduce nasal congestion and coughing

In summary, home remedies work better than medicines for treating coughs and colds.


“Barton Schmitt MD, Copyright 1-28-2008”   Permission granted to make copies for patient care purposes.


This is for the information and use of my patients.   If you have questions or are  concerned about your child or relative,  contact your physician or seek medical care.

No honey or syrup is to given under 12 months of age.