From the Guidelines
It is not recommended to take Claritin (loratadine) and Zyrtec (cetirizine) together daily, as this combination may increase the risk of side effects without providing significant additional benefits. Both medications are second-generation antihistamines that work in similar ways to block histamine receptors and relieve allergy symptoms 1. Taking them together doesn't typically provide additional benefit but may increase the risk of side effects such as drowsiness, dry mouth, headache, and dizziness.
Key Considerations
- If you're not getting adequate relief from one antihistamine alone, it's better to consult with your healthcare provider who might recommend either switching to a different antihistamine, adjusting the dosage, or adding a different class of allergy medication like a nasal corticosteroid or decongestant 1.
- Each antihistamine has a standard adult dose (Claritin 10mg once daily, Zyrtec 10mg once daily), and they work slightly differently for different people, so finding the one that works best for your specific symptoms is preferable to combining them.
- Intranasal corticosteroids are the most effective medication class in controlling symptoms of allergic rhinitis, and may be a better option for patients with severe symptoms 1.
Alternatives to Consider
- Nasal corticosteroids, which have been shown to be more effective than antihistamines in controlling symptoms of allergic rhinitis 1.
- Decongestants, which can help relieve nasal congestion and other symptoms.
- Immunotherapy, which can help desensitize you to specific allergens and provide long-term relief. If your allergy symptoms are severe enough that you're considering taking multiple antihistamines, this suggests your current treatment plan may need adjustment by a healthcare professional.
From the Research
Safety of Using Claritin and Zyrtec Together
- There are no direct studies on the safety of using Claritin (loratadine) and Zyrtec (cetirizine) together daily in the provided evidence.
- However, studies have compared the efficacy and safety of combination therapy with antihistamines, such as cetirizine and loratadine, in treating allergic rhinitis 2, 3.
- A study found that combination therapy with cetirizine, loratadine, and chlorpheniramine was effective in improving nasal congestion and had a lower chance of tolerance and re-appearance of complaints 3.
- Another study compared the onset of action of cetirizine and loratadine in patients with allergic rhinitis and found that cetirizine had a more rapid onset of action than loratadine 4.
- There is no evidence to suggest that using Claritin and Zyrtec together daily is safe or effective, and it is recommended to consult with a healthcare professional before taking any medication.
Efficacy of Combination Therapy
- Combination therapy with antihistamines, such as cetirizine and loratadine, may be effective in treating allergic rhinitis, but more studies are needed to confirm this 2, 3.
- The efficacy of combination therapy may depend on the specific medications used, the dosage, and the individual patient's response to treatment.
- More research is needed to determine the safety and efficacy of using Claritin and Zyrtec together daily.
Potential Interactions
- There is limited information on the potential interactions between Claritin and Zyrtec, but it is possible that taking both medications together may increase the risk of side effects, such as drowsiness or dry mouth.
- It is recommended to consult with a healthcare professional before taking any medication, especially if you are already taking other medications or have underlying medical conditions.