What Is Cetirizine?

Cetirizine is an antihistamine medication used to relieve allergy symptoms such as hay fever, hives (urticaria), and eczema. It helps reduce itching, sneezing, watery eyes, and a runny nose caused by allergic reactions.

How Cetirizine Works

During an allergic reaction, the body releases a chemical called histamine, which causes symptoms like itching, swelling, and sneezing. Cetirizine works by blocking histamine receptors, preventing histamine from triggering these symptoms and helping to relieve allergy discomfort.

How to Take Cetirizine

Cetirizine is usually taken once daily. It can be taken with or without food, and taking it at the same time each day can help maintain consistent symptom control.

When Cetirizine Starts Working

Cetirizine works relatively quickly. Many people notice an improvement in allergy symptoms within a few hours, with full relief often felt by the end of the day.

Possible Side Effects

Most people tolerate cetirizine well. Common side effects may include mild drowsiness, dry mouth, or nausea, particularly when first starting treatment. These effects are usually temporary.

Rare side effects can include a rapid or irregular heartbeat. If this occurs, stop taking cetirizine and seek medical advice from your GP or contact NHS 111.

Always read the Patient Information Leaflet before use and follow the recommended dosage.