Warnings

Inform your doctor about all of your health issues, including any allergies or illnesses, any medications you take, and if you are pregnant or nursing before using Zyrtec.

Your thoughts or reactions might be affected by Zyrtec. If you drive or do anything else that calls for alertness, use caution. Alcohol use might exacerbate some cetirizine adverse effects.

If you routinely use any other medications that make you sleepy, let your doctor know (such as other cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They may increase the drowsiness brought on by Zyrtec. If your symptoms do not get better, if they worsen, or if you also have a fever, call your doctor.