Cetirizine – Uses, Side Effects and More

Overview

Uses

Cetirizine is commonly used to treat:

• Allergic rhinitis (seasonal and perennial) – sneezing, runny nose, nasal itching, watery eyes.
• Chronic urticaria (hives) – reduces itching and the number/severity of hives.
• Allergic conjunctivitis – itchy, red, watery eyes.
• Skin allergies – itching from insect bites, mild allergic skin reactions.
• Atopic dermatitis / eczema (off-label) – to ease itching.

It works by blocking H1 histamine receptors, preventing the body’s reaction to allergens like pollen, dust mites, pet dander, and mold spores.

Dosage

• Adults and children 12+: 10 mg once daily.
• Children 6–11 years: 5–10 mg once daily.
• Children 2–5 years: 2.5–5 mg once daily (syrup form).
• Kidney/liver impairment: Lower dose (5 mg) typically advised.

It can be taken with or without food, and is best taken at the same time each day.

Common Side Effects

• Drowsiness or fatigue (most common)
• Dry mouth
• Headache
• Dizziness
• Nausea or stomach discomfort
• Sore throat

Serious Side Effects (Seek Medical Help)

• Difficulty breathing or swallowing.
• Swelling of face, lips, tongue, or throat (angioedema).
• Fast or irregular heartbeat.
• Severe drowsiness or confusion.
• Difficulty urinating.
• Severe itching after stopping long-term use (rare withdrawal symptom).

Precautions

• Avoid alcohol it intensifies drowsiness.
• Use caution when driving or operating machinery until you know how it affects you.
• Inform your doctor if you have kidney disease, liver disease, urinary retention, or epilepsy.
• Generally considered safe during pregnancy (consult your doctor).
• Passes into breast milk in small amounts discuss with your doctor before breastfeeding.

Drug Interactions

Cetirizine has fewer interactions than older antihistamines, but be cautious with:

• CNS depressants (sedatives, opioids, sleep aids, alcohol) added drowsiness.
• Theophylline may increase cetirizine levels.
• Ritonavir may raise cetirizine concentration in the body.
• Other antihistamines avoid combining.

Storage

Store at room temperature (15–30°C / 59–86°F), away from moisture, heat, and direct light. Keep out of reach of children.

Missed Dose

Take it as soon as you remember. If it’s almost time for your next dose, skip the missed one do not double up.

Overdose

Symptoms of overdose may include extreme drowsiness, restlessness, irritability, rapid heartbeat, or fainting. Seek emergency medical help immediately.

Disclaimer

All information contained in this article is intended for education and information and should not be used as a replacement for medical advice, medical diagnosis or treatment. Consult a qualified healthcare professional such as a physician, pharmacist or other qualified health care provider for any questions you may have about a medical condition or medication. Do not avoid or ignore medical advice or delay getting medical attention on the basis of information contained in this site. The answer to the question about the use of drugs, dosages, side effects, and interactions may differ depending on the individual’s health status, age and other drugs used. Do not start, stop or alter the dosage of any medication without first consulting with your doctor.