What is the active ingredient difference between Zyrtec and Allegra?
Both Zyrtec (cetirizine) and Allegra (fexofenadine) are antihistamines used to treat seasonal allergic rhinitis, allergic conjunctivitis, and uncomplicated skin allergies. However, they have distinct active ingredients and work in different ways. [1]
How do the side effect profiles compare?
While both medications are generally well-tolerated, they have some differences in their side effect profiles. Zyrtec is known to cause drowsiness, dry mouth, and headache, whereas Allegra is associated with a higher incidence of diarrhea and dyspepsia. [2]
What about cost and availability?
The prices of Zyrtec and Allegra vary depending on the country and location. However, Allegra is generally cheaper than Zyrtec and is available in generic form. In the United States, Zyrtec is marketed as a brand-name drug, while Allegra is available as a generic version called fexofenadine hydrochloride. [3]
How long do they stay in your system?
Cetirizine (Zyrtec) has a longer half-life of around 8-10 hours, whereas fexofenadine (Allegra) has a shorter half-life of approximately 14 hours. This difference may influence when each medication lasts in your system. However, this information can be critical to the optimal management of your allergies. [4]
Who makes these medications?
Zyrtec is manufactured by McNeil Consumer Healthcare, a subsidiary of Johnson & Johnson, while Allegra is produced by Sanofi. Both medications are widely available over-the-counter.
Patent information
The patent for Zyrtec (cetirizine) expired in 2007, allowing generic versions to enter the market. In contrast, Allegra's (fexofenadine) patent has been subject to ongoing litigation, particularly in relation to a patent dispute in Canada. [5]
References
[1] https://www.drugpatentwatch.com/DrugPatentWatch/drug/1000000003/Zyrtec
[2] https://www.rxlist.com/allegra-dr-side-effects/
[3] https://www.drugpatentwatch.com/DrugPatentWatch/drug/1030000019/Allegra
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4321915/
[5] https://www.google.com/search?q=%22allegra+patent+dispute%22
*https://www.cbc.ca/news/canada/toronto/allegra-patent-dispute-1.5045116