Cetirizine is a second-generation antihistamine. Doctors recommend it for hay fever, hives, and other allergies. It works for 24 hours and causes less drowsiness than older antihistamines, although some people still feel sleepy.
What Is Cetirizine Used For?
- Hay fever (allergic rhinitis)
- Sneezing, runny nose, and itchy, watery eyes
- Hives (urticaria)
- Itchy skin from allergies
How Does Cetirizine Work?
During an allergic reaction, your body releases histamine. Cetirizine blocks histamine at the H1 receptors, so sneezing, itching, and watery eyes ease.
General Dosage Information
This is general information only. Your doctor sets the right dose for you, so follow your prescription and the label.
- Adults and children over 6 years usually take 10 mg once a day, or 5 mg in the morning and 5 mg in the evening.
- A doctor decides the dose for children from 2 to 6 years.
- People with kidney or liver disease and older adults may need a lower dose.
Side Effects of Cetirizine
Common Side Effects
- Drowsiness and tiredness
- Dry mouth
- Headache
- Sore throat
- Stomach pain
Serious Side Effects
Call your doctor or get emergency help if you notice:
- Swelling of the face, lips, or throat
- Trouble breathing
- Fast heartbeat
- Difficulty passing urine
Who Should Be Cautious?
- People with kidney disease
- People who drive or work with machinery, until they know how it affects them
- Pregnant or breastfeeding women should ask their doctor
- Older adults
Drug Interactions
Tell your doctor and pharmacist about every medicine and supplement you take. Examples of important interactions include:
- Alcohol and sedatives: they add to drowsiness.
- Other antihistamines: do not take them together.
- Theophylline: cetirizine can slightly change its level.
Storage and Precautions
- Store it at room temperature, away from heat, light, and moisture.
- Keep it out of the reach of children.
Frequently Asked Questions
Will cetirizine make me sleepy?
It can, but less often than older antihistamines. Take it in the evening if it makes you drowsy.
Can I take it every day?
Yes, for ongoing allergies, if your doctor agrees.
How fast does it work?
It starts working in about one hour.
Disclaimer: This article is for information only. It is not medical advice. Please talk to your doctor about your own health.