Diphenhydramine Uses

Diphenhydramine is an over-the-counter antihistamine that is used to treat symptoms like red, irritated, itchy, watery eyes, sneezing, and runny nose related to the common cold, hay fever, and other respiratory allergies. Diphenhydramine may also be used to relieve cough caused by minor throat irritation. It is also used to prevent and treat motion sickness, and insomnia. Sometimes, diphenhydramine is prescribed to treat abnormal movements in people with early stages of Parkinson’s disease.

There may be other uses of diphenhydramine —your doctor or pharmacist can give you further drug information.

Diphenhydramine Mechanism of Action

Diphenhydramine works by blocking the action of a certain natural substance in the body called histamine that causes allergy symptoms.

Diphenhydramine Doses

Diphenhydramine is available as 25 mg and 50 mg tablets, and 12.5 mg/5 mL liquid. The usual dose of diphenhydramine in adults and children 12 years of age and older is 25 mg to 50 mg every 4-6 hours as needed. The diphenhydramine dose in children between 6 and 11 years of age is 12.5 mg to 25 mg every 4-6 hours as needed. Children younger than 6 years of age should not receive diphenhydramine without a doctor’s approval.