Cetirizine is the active ingredient of Zyrtec, Texa, Adco-Cetirizine, Allecet, Allermine, Aspen Cetirizine, Austell Cetirizine, Cetirizine-Hexal, Sandoz Cetirizine, Zetop and Zyncet.
General Information
Cetirizine is an antihistamine used for the treatment of allergic conditions, mainly hay fever and skin conditions. Unlike many older antihistamines, cetirizine has very little sedative effect, meaning that you won't feel drowsy after taking this drug. It may still cause drowsiness in a small percentage of people taking it.
Cetirizine has a long term effect and only needs to be taken once a day.
How does cetirizine work?
When you are exposed to an allergen (something you are allergic to) your body reacts by producing a chemical, histamine. Histamine causes the symptoms that we associate with allergy. These include itchy, red, watery eyes; sneezing and runny, itchy nose; postnasal drip; an itchy, sometimes visibly red skin.
Cetirizine is an antihistamine, meaning that it counteracts the action of histamine to help relieve you of the symptoms of allergy.
Fast facts
Drug schedule: Schedule 2
Available as: Cetirizine is available as tablets, syrup and oral drops.
What does it do? Cetirizine has an anti-allergy effect.
Overdose risk: Medium
Dependence risk: Low
Is cetirizine available as a generic? Yes
Is cetirizine available on prescription only? No
User information
Onset of effect: Within 2 hours
Duration of action: Up to 24 hours
Dietary advice: Cetirizine can be taken with or without food.
Stopping this medicine: Cetirizine can be safely stopped when no longer needed.
Prolonged use: No special precautions
Special precautions
Consult your doctor before using this drug if:
- you have kidney or liver disease
- you have a known allergy to the product
- you are taking other medication.
Pregnancy: Avoid. It is unknown how this medication may affect your baby. Consult your doctor before using this drug, or if you are planning to fall pregnant.
Breastfeeding: Avoid. It is unknown how this medication may affect your baby. Consult your doctor before use.
Porphyria: Avoid. It is unknown how this medication may affect your condition. Consult your doctor before use.
Infants and children: Safety and efficacy of this medication has not been established for children under the age of two.
Elderly: Age-related kidney function impairment may require a reduction in dose.
Driving and hazardous work: Caution is advised, as use of this medication may lead to dizziness, light-headedness and/or sedation. Avoid such activities until you know how this medication affects you.
Alcohol: Avoid concomitant use of alcohol with this medication, as it may cause severe sedation.
Possible side effects
Side effect |
Frequency |
Consult your doctor |
Common |
Rare |
Only if severe |
In all cases |
Drowsiness |
|
x |
x |
|
Fatigue |
|
x |
x |
|
Headache |
|
x |
x |
|
Dry mouth |
|
x |
x |
|
Increased appetite |
|
x |
x |
|
Interactions
Drug interactions
Barbiturates |
Potential for enhanced sedation |
Benzodiazepines |
Potential for enhanced sedation |
Hypnotics |
Potential for enhanced sedation |
Sedatives |
Potential for enhanced sedation |
Disease interactions
Consult your doctor before using this drug if you have kidney or liver disease, or if you have been diagnosed with glaucoma.
Overdose action
A small overdose is no cause for concern. In case of intentional large overdose, seek emergency medical attention. Symptoms may include drowsiness and nausea.
Recommended dosage
Adults: 10 mg once daily (or 5mg twice a day)
Children:
2-6 years: 5 mg daily in 1-2 divided doses
6-12 years: As for adults