Diphenhydramine

Definition

Diphenhydramine is an antihistamine commonly used to relieve symptoms of allergy, hay fever, and the common cold. It also has sedative properties and is sometimes used as a sleep aid.

5 Must Know Facts For Your Next Test

1. Diphenhydramine works by blocking histamine receptors to reduce allergy symptoms like sneezing and itching.
2. It can cause drowsiness, so patients are advised not to drive or operate heavy machinery after taking it.
3. In cancer therapy, diphenhydramine may be used to manage allergic reactions to chemotherapeutic drugs.
4. It is available over-the-counter in various forms such as tablets, capsules, and liquid solutions.
5. Besides its antihistamine effects, diphenhydramine can also be used to treat motion sickness and insomnia.

Review Questions

• What is the primary mechanism of action for diphenhydramine?
• Why should patients avoid driving after taking diphenhydramine?
• In what scenarios might diphenhydramine be used during cancer therapy?

Related terms

Antihistamines: Drugs that block histamine receptors to reduce allergy symptoms.

Decongestants: Medications that relieve nasal congestion by narrowing blood vessels in the nasal passages.

Cerumenolytics: Agents used to soften and remove earwax (cerumen) from the ear canal.