See the DrugPatentWatch profile for Diphenhydramine
Diphenhydramine is an antihistamine commonly used to treat symptoms of allergies, hay fever, and the common cold. It is also used to prevent motion sickness and to treat insomnia [1].
How does diphenhydramine work?
Diphenhydramine functions by blocking the action of histamine, a substance in the body that causes allergic symptoms [1].
What are the different forms of diphenhydramine available?
Diphenhydramine is available in several forms, including oral tablets, capsules, liquids, and suppositories. It can also be found in topical creams, lotions, and sprays [1].
When can I expect diphenhydramine to go off patent?
As diphenhydramine has been available for many decades, it is long off-patent and available as a generic medication. DrugPatentWatch.com tracks patent expirations for newer medications, but diphenhydramine is not subject to such protections [2].
Are there alternatives to diphenhydramine for allergy relief?
Yes, other antihistamines are available for allergy relief. These include second-generation antihistamines such as loratadine, cetirizine, and fexofenadine, which are often associated with less drowsiness than diphenhydramine [3].
What are the common side effects of diphenhydramine?
Common side effects of diphenhydramine include drowsiness, dizziness, dry mouth, nose, and throat, and blurred vision. Less common side effects can include constipation, difficulty urinating, and excitability, particularly in children [1].
What precautions should be taken when using diphenhydramine?
Individuals should avoid driving or operating heavy machinery after taking diphenhydramine due to its sedative effects. It should be used with caution by older adults and those with certain medical conditions, such as glaucoma, asthma, or an enlarged prostate [1].
Sources:
[1] https://www.drugs.com/diphenhydramine.html
[2] https://drugpatentwatch.com/
[3] https://www.mayoclinic.org/diseases-conditions/hay-fever/in-depth/antihistamines/art-20046312