From the Guidelines
Taking 2 Zyrtec (cetirizine) tablets at once is generally not recommended without consulting a healthcare provider first. The standard adult dose of Zyrtec is 5-10 mg (one tablet) once daily, depending on the formulation. According to a study published in the Journal of Allergy and Clinical Immunology 1, taking more than the recommended dose may increase the risk of side effects such as drowsiness, dry mouth, fatigue, and headache without necessarily improving symptom relief.
Some key points to consider:
- Cetirizine 10 mg may be associated with mild drowsiness (13.7% for patients age 12 years) compared with placebo (6.3%) 1
- Development of drowsiness without performance impairment has been observed with both Cetirizine 10 mg (the standard dose) and 20 mg 1
- However, in other studies, the 10 mg or higher dose of Cetirizine was associated with performance impairment 1
- Among the newer, nonsedating antihistamines, no single agent has been conclusively found to achieve superior overall response rates 1
If you feel that one Zyrtec isn't adequately controlling your allergy symptoms, it's better to speak with your healthcare provider who might recommend a different antihistamine, adding another type of allergy medication, or addressing the underlying cause of your allergies rather than simply doubling your Zyrtec dose.
From the FDA Drug Label
Directions Adults and children 6years and overone 10 mg tablet once daily, do not take more than one 10 mg tablet in 24 hours. The answer is no, it is not okay to take 2 Zyrtecs (cetirizine) as the label explicitly states do not take more than one 10 mg tablet in 24 hours 2.
From the Research
Dosage of Zyrtec (Cetirizine)
- The standard dose of Zyrtec (cetirizine) is 5-10 mg once daily 3, 4, 5.
- However, some studies suggest that increasing the dose up to 20 mg daily may be effective for patients with refractory symptoms of allergic rhinitis or urticaria 3, 6, 7.
- A study published in 1995 found that 41.6% of patients increased their dose to 15 or 20 mg/d, and 82% of patients showed improvement on cetirizine 3.
- Another study published in 2010 found that increasing the dosage of levocetirizine and desloratadine up to 4-fold improved chronic urticaria symptoms without compromising safety in approximately three quarters of patients with difficult-to-treat chronic urticaria 6.
- A study published in 2013 found that doubling the dose of cetirizine was effective for patients with urticaria resistant to the standard dose of cetirizine 7.
Safety and Efficacy
- The safety and efficacy of cetirizine have been established in several studies 3, 6, 7, 4, 5.
- Cetirizine has been found to be well tolerated, with minimal side effects 3, 5.
- However, it is essential to follow the recommended dosage and consult a healthcare professional before taking any medication, especially if you have any underlying medical conditions or are taking other medications 3, 6, 7, 4, 5.
Taking 2 Zyrtec (Cetirizine)
- Based on the available evidence, taking 2 Zyrtec (cetirizine) may be equivalent to taking 10-20 mg of cetirizine, which is within the range of doses studied in some clinical trials 3, 6, 7.
- However, it is crucial to consult a healthcare professional before taking any medication, especially if you have any underlying medical conditions or are taking other medications 3, 6, 7, 4, 5.