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 maximum recommended dose of cetirizine is 10 mg per day, and it should not be taken more than once in 24 hours 1.
From the Research
The maximum recommended dose of cetirizine for adults and children 6 years and older is 10 mg once daily. For children 2-5 years old, the maximum dose is 5 mg once daily or 2.5 mg twice daily. For elderly patients or those with renal impairment (reduced kidney function), the dose should be reduced to 5 mg once daily. Cetirizine is a second-generation antihistamine that works by blocking histamine receptors, reducing allergy symptoms like sneezing, itching, watery eyes, and runny nose. It causes less drowsiness than older antihistamines because it doesn't cross the blood-brain barrier as readily. The medication typically starts working within an hour and lasts for 24 hours, allowing for once-daily dosing.
Some key points to consider when prescribing cetirizine include:
- The efficacy and safety of cetirizine have been established in numerous trials, including a study published in 2004 2 that reviewed its use in allergic disorders.
- The medication has anti-inflammatory properties that may play a role in asthma management, as noted in a study from 1993 3.
- Cetirizine has been shown to be effective in the treatment of various forms of urticaria and reduces the pruritus of atopic eczema, as reported in a study from 1999 4.
- The safety of cetirizine in infants 6 to 11 months of age has been documented in a randomized, double-blind, placebo-controlled study published in 2003 5.
- A study from 1994 6 assessed the efficacy and safety of three dose levels of cetirizine given once daily in children with perennial allergic rhinitis, finding that a 10-mg dose was effective in treating the condition.
Taking higher than recommended doses won't improve effectiveness but may increase side effects like drowsiness, dry mouth, and headache. If allergy symptoms aren't controlled with the maximum dose, consult a healthcare provider as additional or alternative treatments may be needed.