Allergies Home > More Info on Benadryl Indications
How Does It Work?
Benadryl is part of a class of drugs called antihistamines. Specifically, it is an H1 receptor antagonist. This means that it blocks a specific type of histamine receptor in the body (known as H1 receptors). Since allergic reactions are partly caused by the release of histamine from certain cells in the body, Benadryl can help relieve or prevent allergy symptoms.
Benadryl also blocks acetylcholine receptors, an action which produces some of the bothersome side effects of the medication (such as dry mouth or difficulty urinating) but also makes the drug useful for some uses of the medications (such as for Parkinson's disease or for relieving a runny nose due to the common cold).
Like many antihistamines, Benadryl also works as a sedative. This action has made the medication useful as a sleep aid but also limits the usefulness of the medication for other uses (since drowsiness can be a bothersome side effect).
Benadryl Uses in Children
Oral Children's Benadryl products are approved for treating allergies (such as hay fever) in children ages six years and older. Adult Benadryl oral products are approved for treating allergies or cold symptoms in children ages six years and older. Topical (skin) products are approved for use in children ages two years and older.
Benadryl is usually not recommended as a medication to make a child drowsy. Not only can this practice be dangerous, but it is often ineffective. In fact, Benadryl can have an opposite effect on children, sometimes making them hyperactive.
Off-Label Uses for Benadryl
On occasion, your healthcare provider may recommend Benadryl for something other than the approved uses (this would be known as an "off-label" use). Off-label uses of Benadryl include the treatment of the following conditions:
- Morning sickness (see Benadryl and Pregnancy)
- Attention deficit hyperactivity disorder (ADHD)
- Extrapyramidal symptoms due to antipsychotic medications and other medications.
Benadryl is also used off-label for preventing negative reactions to certain cancer medications.
Additionally, using non-prescription Benadryl for the uses that are only approved for the prescription form would also be considered to be off-label. Such uses include the treatment of the following conditions:
- Allergic reactions, such as food allergies or bee stings
- Dermatographism, a severe form of hives
- Motion sickness
- Parkinson's disease