Cetirizine vs Fexofenadine: side-by-side comparison
Cetirizine and Fexofenadine belong to the same class (Second-generation H1 antihistamine). They share therapeutic approach but differ in mechanism nuances, half-life, side-effect profile and available formulations. This comparison summarises what is common and where they diverge.
| Property | Cetirizine | Fexofenadine |
|---|---|---|
| Therapeutic class | Second-generation H1 antihistamine | Second-generation H1 antihistamine |
| CAS | 83881-51-0 | 83799-24-0 |
| ATC | R06AE07 | R06AX26 |
| Molecular weight | 388.89 g/mol | 501.66 g/mol |
| Brands with this active ingredient | 1 | 1 |
What they share
Both are in the Second-generation H1 antihistamine class, giving them a common pharmacological architecture and many shared safety and management points. Choice within the class comes down to mechanism nuances, half-life, side-effect profile and individual response.
Key differences
Differences within the Second-generation H1 antihistamine class are what matter in practice: half-life, route of administration, equivalent doses, specific interactions, predominant side-effect profile and accumulated clinical experience. This page frames them; the prescribing information gives quantitative detail.
Mechanisms compared
Cetirizine: Cetirizine selectively blocks peripheral H1 histamine receptors, antagonising the effects of histamine released by mast cells during allergic responses. Fexofenadine: Fexofenadine selectively blocks peripheral H1 histamine receptors, antagonising the effects of histamine on vasodilation, capillary permeability, sensory nerve endings and smooth muscle.
Indications compared
Cetirizine: Cetirizine is approved in adults and children for the treatment of allergic rhinitis, including seasonal and perennial forms, allergic conjunctivitis and chronic idiopathic urticaria. Fexofenadine: Fexofenadine is approved in adults and children for the treatment of seasonal allergic rhinitis and chronic idiopathic urticaria.
Safety profile
Cetirizine: Cetirizine is generally well tolerated. Fexofenadine: Fexofenadine is very well tolerated.
Frequently asked questions
Is Cetirizine better than Fexofenadine? ▾
Neither is universally better. Cetirizine and Fexofenadine share the Second-generation H1 antihistamine class but differ in half-life, mechanism nuances and side-effect profile. The choice depends on the patient and the prescriber.
Can Cetirizine and Fexofenadine be combined? ▾
Combining two ingredients from the same Second-generation H1 antihistamine class is uncommon and, in most cases, adds no benefit over one at an appropriate dose. The decision is always the prescriber's.
Do they have the same side-effect profile? ▾
Partly yes — they share many Second-generation H1 antihistamine class effects, with nuances by mechanism and dose. The prescribing information lists differences.
Products with Cetirizine
Products with Fexofenadine
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.