Is zyrtec an antihistamine?
Antihistamines treat allergy symptoms like runny nose, itchy or watery eyes, sneezing, and can also treat some digestive issues or motion sickness. They block histamine receptors. Zyrtec (cetirizine HCl) is an H1 antihistamine and a second-generation agent with fewer side effects (such as drowsiness) and fewer drug interactions than first-generation antihistamines like Benadryl (diphenhydramine).
Zyrtec is available as tablets, liquid gels, chewable and dissolvable tablets, liquid, and Zyrtec-D (which also contains a decongestant).
What does Zyrtec treat?
- Allergic rhinitis (hay fever)
- Allergic skin reactions (atopic dermatitis)
- Sinus infection (sinusitis)
- Hives
- Angioedema (allergic skin swelling)
How does Zyrtec work?
Cetirizine blocks H1 histamine receptors. Histamine is released in response to allergens (pollen, foods, insect stings, dust, medications, pet dander), causing allergy symptoms. Zyrtec relieves these symptoms in adults and children ≥ 2 years.
Side effects of Zyrtec
- Drowsiness (in some people)
- Headache
- Dizziness
- Dry mouth
- Sore throat
Rare serious side effects:
- Allergic reactions
- Excessive drowsiness with alcohol or sedatives
- Trouble urinating (especially with enlarged prostate)
- Worsened glaucoma
What to tell your healthcare provider
- Use of alcohol, sedatives, or tranquilizers
- Difficulty urinating or enlarged prostate
- Liver or kidney disease
- Allergy to cetirizine or other antihistamines (loratadine, hydroxyzine, fexofenadine)
- Pregnancy or plans to become pregnant
- Breastfeeding or plans to breastfeed
Alternatives to Zyrtec
- Claritin (loratadine)
- Allegra (fexofenadine)
- Xyzal (levocetirizine)
- Benadryl (diphenhydramine)
- Clarinex (desloratadine)
Is Zyrtec the strongest antihistamine?
No single antihistamine is universally strongest. Allegra may be best for eye symptoms, Xyzal for sneezing and itchy nose, and Claritin slightly less effective overall. Individual response varies. Nasal steroids are often recommended first as the most effective option.
Sources
- Zyrtec (cetirizine hydrochloride) Tablets and Syrup For Oral Use. Pfizer. Last updated 5/2019. Accessed Apr 7, 2025.
- Naqvi A, Patel P, Gerriets V. Cetirizine. StatPearls. Updated May 6, 2024. Accessed Apr 7, 2025.
- Hong D et al. Efficacy of different oral H1 antihistamine treatments on allergic rhinitis: systematic review and network meta-analysis. Braz J Otorhinolaryngol. 2023;89(4):101272. Accessed Apr 7, 2025.