Can you take Allegra (fexofenadine) with Zyrtec (cetirizine) combined?

From the Guidelines

It is generally not recommended to take Allegra (fexofenadine) and Zyrtec (cetirizine) together. These medications are both second-generation antihistamines that work in similar ways to block histamine receptors and relieve allergy symptoms. Taking them together doesn't provide additional benefit but increases the risk of side effects such as drowsiness, dry mouth, headache, and dizziness.

• Instead, choose one antihistamine and take it as directed - typically Allegra 60mg twice daily or 180mg once daily, or Zyrtec 10mg once daily.
• If one medication isn't effective for your allergy symptoms, try switching to the other rather than combining them.
• If your allergy symptoms are severe enough that you're considering taking multiple antihistamines, consult with your healthcare provider who might recommend adding a different class of allergy medication such as a nasal steroid spray or a leukotriene modifier rather than combining antihistamines, as recommended by the 2017 Joint Task Force on Practice Parameters 1. Some key points to consider when treating seasonal allergic rhinitis include:
• Intranasal corticosteroids are the most effective medication class in controlling symptoms of allergic rhinitis 1.
• The combination of an intranasal corticosteroid and an intranasal antihistamine may be considered for initial treatment of moderate to severe seasonal allergic rhinitis 1.
• Leukotriene receptor antagonists may also provide benefit for seasonal allergic rhinitis, but are not the preferred agent for initial treatment 1.

From the Research

Combination of Allegra and Zyrtec

• The combination of Allegra (fexofenadine) and Zyrtec (cetirizine) is not directly addressed in the provided studies.
• However, studies have compared the efficacy and safety of fexofenadine and cetirizine individually in the treatment of seasonal allergic rhinitis 2, 3.
• One study found that fexofenadine 120 mg once daily and cetirizine 10 mg once daily had similar efficacy in reducing total symptom scores in patients with seasonal allergic rhinitis 3.
• Another study found that fexofenadine was as effective as cetirizine in the treatment of seasonal allergic rhinitis, with both medications providing significant relief from symptoms 2.

Safety and Efficacy

• Fexofenadine and cetirizine are both second-generation antihistamines that are generally well-tolerated and have a low risk of adverse effects 2, 3.
• However, the combination of these two medications may increase the risk of adverse effects, such as drowsiness or fatigue, although this is not directly addressed in the provided studies.
• The onset of action for fexofenadine and cetirizine has been studied, with fexofenadine having an onset of action within 60 minutes and cetirizine having an onset of action ranging from 59 minutes to 2 hours and 6 minutes 4.

Treatment of Allergic Rhinitis

• Allergic rhinitis is a common condition that affects millions of people worldwide, and treatment options include second-generation antihistamines like fexofenadine and cetirizine 5.
• The choice of treatment depends on the severity and frequency of symptoms, as well as patient preference 5.
• Combination therapy with a second-generation antihistamine and a decongestant may be beneficial for patients with severe congestion 6.