What is cetirizine dihydrochloride?

Updated April 17, 2017

Cetirizine dihydrochloride, sometimes called cetirizine hydrochloride, refers to an antihistamine used to treat symptoms of allergies or hay fever, such as runny nose, itchy eyes and sneezing. Cetirizine dihydrochloride is available over-the-counter as Zyrtec.


Adults and children over 6 years old should take no more than 10 mg of cetirizine dihydrochloride daily. Children under 6 should take no more than 5 mg daily. Patients over 65 should take no more than 5 mg daily.

Side Effects

Common side effects in adults include fatigue, dry mouth and insomnia. Children sometimes experience pharyngitis, headaches and abdominal pain. Children under 2 years may exhibit fussiness, fatigue or irritability.


Store cetirizine dihydrochloride in a dry, dark location between 20 and 25 degrees Celsius. Do not use if the inner seal is broken. Keep cetirizine dihydrochloride away from children.


If an overdose occurs, call the Poison Control Center at 1-800-222-1222.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Rebekah Richards is a professional writer with work published in the "Atlanta Journal-Constitution," "Brandeis University Law Journal" and online at She graduated magna cum laude from Brandeis University with bachelor's degrees in creative writing, English/American literature and international studies. Richards earned a master's degree at Carnegie Mellon University.