Diphenhydramine

Diphenhydramine is a first-generation antihistamine that is used to relieve symptoms of allergies, hay fever, and the common cold. It is also used as a sleep aid due to its sedative effects.

Indications

Diphenhydramine is indicated for the relief of symptoms caused by allergies, such as sneezing, itching, watery eyes, and runny nose. It is also used to treat allergic skin reactions, motion sickness, and to induce sleep.

Dosage

The dosage of diphenhydramine varies depending on the age, weight, and condition being treated. It is typically taken orally in tablet or liquid form, with or without food. It is important to follow the dosage instructions provided by a healthcare professional or as directed on the product label.

Contra-Indications

Diphenhydramine is contraindicated in individuals who are hypersensitive to the drug or its components. It should also be avoided in patients with narrow-angle glaucoma, urinary retention, severe hypertension, or during an acute asthma attack.

Special Precautions

Caution should be exercised when using diphenhydramine in elderly patients, as they may be more susceptible to its side effects, such as dizziness, sedation, and confusion. It should be used with caution in patients with a history of asthma, bronchitis, or other respiratory conditions, as it may cause respiratory depression.

Side Effects

Common side effects of diphenhydramine include drowsiness, dry mouth, blurred vision, constipation, and urinary retention. Less common side effects may include confusion, hallucinations, and palpitations.

Drug Interactions

Diphenhydramine may interact with other medications, including alcohol, sedatives, tranquilizers, and monoamine oxidase inhibitors (MAOIs), resulting in increased sedation and central nervous system depression. It may also potentiate the effects of anticholinergic drugs.