Zyrtec (cetirizine) is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. User Reviews for Zyrtec. The following information is NOT intended to endorse drugs or recommend therapy. While these reviews might be helpful, they are not a substitute for the expertise, skill, knowledge and judgement of healthcare practitioners in patient care. The most common question I get asked by my patients is if there are any hives treatment remedies they can use to treat their hives without having to see their dermatologist. I definitely sympathize with them as almost every doctor I know is booked out weeks if not months in advance. A condition characterized by an outbreak of red bumps that appear quickly after exposure to certain allergens (foods, medications, or other substances). They can vary in size, are itchy, can burn, and can last for up to one day or longer. What is Zyrtec? Cetirizine is the generic name for the brand name Zyrtec and is a medication that is used to treat moderate to severe allergies, cold symptoms or chronic hives. First generation antihistamines include medications such as Benadryl (diphenhydramine) and Vistaril/Atarax (hydroxyzine). These medications can be very effective for the treatment of hives or allergies but usually cause significant drowsiness which limits their use. I started taking Zyrtec for seasonal allergies. After a month on this drug, I noticed a lump on my forehead. I initially dismissed it as acne. But it grew rapidly. Zyrtec (cetirizine hydrochloride) is an antihistamine that treats symptoms, such as itching, runny nose, watery eyes, and sneezing from hay fever (allergic rhinitis) and other allergies, such as allergies to molds and dust mites. How to use Zyrtec. If you are taking the over-the-counter product to self-treat, read all directions on the product package before taking this medication. Zyrtec is an antihistamine used to treat seasonal allergies and hives. It is available over the counter, though children under six with hives will still need a prescription.