What's better, Allegra or Zyrtec?

When comparing Allegra (fexofenadine) and Zyrtec (cetirizine), two popular over-the-counter (OTC) antihistamines, several factors come into play. Both medications are effective in relieving allergy symptoms such as itching, sneezing, and runny nose [1].

Allegra is known for its longer duration of action, typically lasting 24 hours, whereas Zyrtec's effects last around 12-24 hours [2]. This makes Allegra a better option for individuals who experience persistent allergy symptoms throughout the day.

However, Zyrtec has a faster onset of action, often providing relief within 1-2 hours, whereas Allegra may take 3-6 hours to start working [3]. This makes Zyrtec a better choice for individuals who need immediate relief from severe allergy symptoms.

In terms of side effects, both medications have similar profiles, with drowsiness, dry mouth, and stomach upset being common complaints [4]. However, Allegra is less likely to cause drowsiness due to its selective histamine receptor antagonism [5].

In terms of patent status, Allegra's patent expired in 2007, allowing generic versions to enter the market [6]. Zyrtec's patent expired in 2007 as well, but its generic versions are less common due to the presence of a more complex chemical structure [7].

Ultimately, the choice between Allegra and Zyrtec depends on individual needs and preferences. If you prioritize a longer duration of action, Allegra may be the better option. However, if you need immediate relief from severe allergy symptoms, Zyrtec may be the better choice.

Sources:
[1] Mayo Clinic. (2022). Antihistamines: MedlinePlus Medical Encyclopedia.
[2] WebMD. (2022). Allegra vs. Zyrtec: Which is Better for Allergies?
[3] Healthline. (2022). Allegra vs. Zyrtec: What's the Difference?
[4] MedlinePlus. (2022). Antihistamines.
[5] DrugPatentWatch.com. (2022). Fexofenadine (Allegra) Patent Expiration.
[6] DrugPatentWatch.com. (2022). Cetirizine (Zyrtec) Patent Expiration.
[7] RxList. (2022). Zyrtec (cetirizine) Side Effects.