Information about Diphenhydramine
Diphenhydramine is a first generation antihistamine that is used for symptoms of allergic rhinitis and the common cold. It is also commonly used as a mild sleeping aid.
Liver safety of Diphenhydramine
Diphenhydramine has not been linked to instances of clinically apparent acute liver injury.
Mechanism of action of Diphenhydramine
Diphenhydramine (dye" fen hye' dra meen) is a first generation antihistamine that is used widely in the therapy of the symptoms of allergic rhinitis and the common cold, including sneezing, cough, runny note, watery eyes and itching. Because of its sedating side effects, it is also used as a mild sleeping aid. In intravenous forms, diphenhydramine is used in the treatment of severe allergic reactions and anaphylaxis. Diphenhydramine belongs to the ethanolamine class of antihistamines (with clemastine and dimenhydrinate) and in 1946 became the first antihistamine approved for use in the United States. It is still widely used today and is available in multiple generic forms as tablets, capsules, liquid oral and intravenous solutions, creams and syrups, many of which are available without prescription.
Brand name for Diphenhydramine
Dosage and administration for Diphenhydramine
The recommended adult oral dose ranges from 25 to 50 mg three or four times daily.
Side effects of Diphenhydramine
Common side effects include sedation, impairment of motor function, confusion, dizziness, blurred vision, dry mouth and throat, palpitations, tachycardia, abdominal distress, constipation and headache. Antihistamines can worsen urinary retention and glaucoma.
First Generation Antihistamines
Second Generation Antihistamines