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. A 5 mg product may be appropriate for less severe symptoms. The recommended dose of Zyrtec (cetirizine) is:
- 10 mg once daily for adults and children 6 years and over
- A 5 mg product may be appropriate for less severe symptoms
- For adults 65 years and over, children under 6 years of age, and consumers with liver or kidney disease: ask a doctor 1
From the Research
The recommended dose of Zyrtec (cetirizine) for adults and children 6 years and older is 5-10 mg once daily, as supported by the most recent study 2. For children 2-5 years old, the recommended dose is 2.5 mg once daily, which can be increased to 5 mg daily given as 2.5 mg twice daily if needed. For children 6-11 months, the dose is 2.5 mg once daily. Elderly patients and those with kidney or liver impairment may need a reduced dose of 5 mg once daily. Zyrtec is an antihistamine that works by blocking histamine receptors, reducing allergy symptoms like sneezing, itching, watery eyes, and runny nose. It's best taken at the same time each day, with or without food. The medication typically starts working within an hour and lasts for 24 hours. Unlike some older antihistamines, Zyrtec causes less drowsiness, though some patients may still experience this side effect, as noted in various studies 3, 4, 5, 6. Key considerations for dosing include:
- Age and weight of the patient
- Severity of symptoms
- Presence of kidney or liver impairment
- Potential for drug interactions As always, it's essential to follow the specific guidance of a healthcare provider when administering Zyrtec, especially in pediatric or geriatric populations, or in those with complex medical conditions, as highlighted in the recent review 2.