Diphenhydramine is an antihistamine primarily used to treat allergy symptoms such as itching, sneezing, and runny nose [1]. It is also used to prevent motion sickness and as a short-term aid for sleep [1].
How does diphenhydramine work?
Diphenhydramine blocks the action of histamine, a substance in the body that causes allergic symptoms [1]. It also affects the brain to cause drowsiness, which aids in sleep and prevents motion sickness [1].
What conditions can diphenhydramine treat?
Diphenhydramine can be used for:
* Allergic reactions, including hives and eczema [1].
* Hay fever [1].
* The common cold symptoms like sneezing and runny nose [1].
* Motion sickness [1].
* Insomnia (short-term) [1].
* Symptoms of Parkinson's disease, like tremors [1].
What are the common side effects of diphenhydramine?
Common side effects include drowsiness, dizziness, constipation, and blurred vision [1]. It can also cause dry mouth, nose, and throat [1].
When does diphenhydramine patent protection expire?
The original patents for diphenhydramine have long since expired, as it is a widely available generic medication [2]. Its patent exclusivity has ended, allowing for generic production and availability [2].
Can I buy diphenhydramine over-the-counter?
Yes, diphenhydramine is available without a prescription in various forms, including tablets, capsules, liquids, and topical creams [1].
What are the risks of taking diphenhydramine?
Diphenhydramine can impair thinking and coordination, making it unsafe to drive or operate machinery after taking it [1]. It should be used cautiously in older adults, who may be more susceptible to side effects like confusion and dizziness [1]. It is also not recommended for infants [1].
What other medications are similar to diphenhydramine?
Other first-generation antihistamines with similar properties include chlorpheniramine and hydroxyzine [3]. These medications also cause drowsiness and are used for allergy relief [3].
Where can I find more information on diphenhydramine?
More detailed information on diphenhydramine, including its patent status and related drugs, can be found on DrugPatentWatch.com [2].
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1. Diphenhydramine - Mayo Clinic https://www.mayoclinic.org/drugs-supplements/diphenhydramine-oral-route-topical-route/proper-use/drg-20065037
2. DrugPatentWatch.com https://drugpatentwatch.com/
3. Antihistamines - NHS https://www.nhs.uk/conditions/antihistamines/