From the Guidelines
No, you should not take Zyrtec (cetirizine) and Loratadine together. These medications are both second-generation antihistamines that work in very similar ways to treat allergy symptoms. Taking them together provides no additional benefit but increases your risk of side effects such as drowsiness, dry mouth, headache, and dizziness. Both medications block histamine receptors in your body to reduce allergy symptoms like sneezing, itching, watery eyes, and runny nose.
Key Points to Consider
- The use of second-generation antihistamines like loratadine and cetirizine is generally preferred over first-generation antihistamines due to their lower potential for sedation and anticholinergic effects 1.
- Among second-generation antihistamines, there are differences in sedative properties: fexofenadine, loratadine, and desloratadine do not cause sedation at recommended doses, while cetirizine may cause sedation at recommended doses 1.
- No single second-generation antihistamine has been conclusively found to achieve superior overall response rates, suggesting that the choice between them may depend on individual patient factors and side effect profiles 1.
- If one antihistamine isn't providing adequate relief, it's better to consult with your healthcare provider who might recommend a different class of allergy medication to add to your regimen, adjust your dosage, or switch you to a different antihistamine altogether.
Recommendations for Use
- Most people should take either Zyrtec or Loratadine once daily, not both.
- If you've accidentally taken both, monitor yourself for increased side effects and contact your healthcare provider if you experience concerning symptoms.
- Consider alternative treatments such as intranasal corticosteroids, which have been shown to be effective in controlling symptoms of allergic rhinitis and may be used in conjunction with antihistamines for enhanced symptom relief 1.
From the Research
Combination of Zyrtec and Loratadine
- There is no direct evidence in the provided studies that specifically addresses the combination of Zyrtec (cetirizine) and loratadine.
- However, studies 2 and 3 discuss the use of second-generation antihistamines, including cetirizine and loratadine, for the treatment of allergic rhinitis.
- Study 4 mentions the combination of fluticasone propionate with an oral antihistamine, loratadine, and found that combination therapy had efficacy comparable to that of intranasal corticosteroid alone.
- Study 5 recommends second-generation H1 antihistamines, such as cetirizine and loratadine, as first-line treatment for mild intermittent or mild persistent allergic rhinitis.
Safety and Efficacy
- Study 3 discusses the safety of second-generation antihistamines, including loratadine and cetirizine, and found that they have excellent safety records and are less likely to produce sedation.
- Study 6 examines the effectiveness of levocetirizine and desloratadine in difficult-to-treat urticaria and found that increasing antihistamine doses improved symptoms without compromising safety.