Is a combination of cetirizine, an antihistamine that reduces the natural chemical histamine in the body, and pseudoephedrine, a decongestant that shrinks blood vessels in the nasal passages. it is used to treat cold or allergy symptoms such as nasal and sinus congestion, sneezing, itching, watery eyes, or runny nose. it is taken orally in tablet form. possible side effects can include dry mouth, dizziness, drowsiness, tiredness, ringing in the ears, or problems with concentration.it is not known whether cetirizine and pseudoephedrine is harmful to an unborn baby. before taking this medication, tell your doctor if you are pregnant or plan to become pregnant during treatment. cetirizine and pseudoephedrine can pass into breast milk and may harm a nursing baby.