From the Guidelines
Cetirizine is an antihistamine medication primarily used to treat allergy symptoms such as sneezing, runny nose, itchy eyes, and hives, with a standard adult dose of 10 mg once daily. The dosing instructions for cetirizine vary based on age and kidney function, with children aged 6-12 years typically taking 5-10 mg once daily, and children 2-5 years taking 2.5 mg once daily 1. For elderly patients or those with kidney impairment, a reduced dose of 5 mg daily is recommended. Cetirizine works by blocking histamine receptors, preventing the allergic response that causes symptoms. It's a second-generation antihistamine, meaning it causes less drowsiness than older antihistamines, though some patients may still experience this side effect, with 13.7% of patients aged 12 years experiencing mild drowsiness compared to 6.3% with placebo 1.
Key Points to Consider
- Cetirizine can be taken with or without food, and the liquid formulation is available for children or those who have difficulty swallowing pills.
- For best results, cetirizine should be taken at the same time each day, and patients should avoid alcohol while using this medication as it may increase drowsiness.
- Unlike some antihistamines, cetirizine can provide relief within an hour of taking it and its effects typically last for 24 hours.
- Second-generation antihistamines such as cetirizine have been shown to be well tolerated and to have a very good safety profile in young children 1.
- The use of cetirizine or intranasal azelastine has been associated with sedative properties compared with placebo, although the effect tends to be milder than that observed with first-generation antihistamines 1.
Important Considerations for Specific Patient Groups
- Children under 6 years: OTC cough and cold medications, including antihistamines, should be avoided due to potential toxicity and lack of efficacy 1.
- Elderly patients or those with kidney impairment: a reduced dose of 5 mg daily is recommended due to increased risk of side effects.
- Patients with low body mass: may conceivably reach an elevated dosage level and develop drowsiness and/or performance impairment 1.
From the FDA Drug Label
PRINCIPAL DISPLAY PANEL-100'S COUNT Rising® 16571-402-10 Original Prescription Strength Cetirizine Hydrochloride Tablets USP 10 mg 6 yrs & older Antihistamine ALLERGY Indoor & Outdoor Allergies 24 Hour Relief of: •Sneezing •Runny Nose •Itchy, Watery Eyes •Itchy Throat or Nose Active Ingredient (in each tablet) Cetirizine HCl USP 10 mg
Cetirizine is an antihistamine used for the 24 Hour Relief of:
- Sneezing
- Runny Nose
- Itchy, Watery Eyes
- Itchy Throat or Nose The dosing instructions are for individuals 6 years and older, with a dosage of 10 mg. 2 2 2
From the Research
What is Cetirizine
- Cetirizine is a selective, second-generation histamine H1 receptor antagonist, with a rapid onset, a long duration of activity and low potential for interaction with drugs metabolised by the hepatic cytochrome P450 system 3.
- It is an effective and well tolerated agent for the treatment of symptoms of seasonal allergic rhinitis (SAR), perennial allergic rhinitis (PAR) and chronic idiopathic urticaria (CIU) in adult, adolescent and paediatric patients 3.
Uses of Cetirizine
- Cetirizine is used to treat allergic disorders such as SAR, PAR, and CIU 3, 4.
- It is also effective in reducing symptoms of allergic asthma in adults and reduced the relative risk of developing asthma in infants with atopic dermatitis sensitised to grass pollen or house dust mite allergens 3.
- Cetirizine has anti-inflammatory properties that may play a role in asthma management 4.
- It is also used to treat allergic cough and mosquito bites, although its precise role in these indications has yet to be clearly established 3.
Dosing Instructions
- The recommended dose of cetirizine for adults is 10 mg/day 4.
- In adult, adolescent and paediatric patients aged 2-11 years, the incidence of somnolence with cetirizine was dose related and was generally similar to that with other second-generation H1 receptor antagonists 3.
- Cetirizine is rapidly absorbed, and significant clinical inhibition of a wheal and flare response occurs in infants, children and adults within 20 min of a single oral dose and persists for 24 h 4.
Safety and Tolerability
- Cetirizine is well tolerated in adults, adolescents and paediatric patients with allergic disorders 3.
- It does not have any adverse effects on cognitive function in adults, or cognitive function, behaviour or achievement of psychomotor milestones in paediatric patients 3.
- Cetirizine was not associated with cardiotoxicity, although a recent study suggests that it may be associated with pericarditis 5.
- Cetirizine poses a greater potential risk in the nervous and psychiatric systems compared to Loratadine, including somnolence, attention disturbance, hallucinations, aggression, and abnormal behavior 5.