Zyrtec Side Effects
While most people have no problems with Zyrtec, it is possible for side effects to occur. Some of the more common side effects in adults include drowsiness, fatigue, and dry mouth. In children, common side effects of Zyrtec include headache, sore throat, and cough. If you experience potentially serious side effects, such as breathing problems or difficulty urinating, contact your healthcare provider immediately.
As with any medicine, side effects are possible with Zyrtec® (cetirizine hydrochloride). However, not everyone who takes the drug will have problems. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or are easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with Zyrtec. Your healthcare provider can discuss a more complete list of Zyrtec side effects with you.)
Zyrtec has been studied thoroughly in clinical trials, in which the side effects of a group of people taking the drug are documented and compared to another group not taking the medicine. As a result, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.
In these studies, the most common side effects of Zyrtec in adults included:
- Drowsiness -- in up to 13.7 percent of people
- Fatigue -- up to 5.9 percent
- Dry mouth -- up to 5 percent (see Zyrtec and Dry Mouth)
- Sore throat -- up to 2 percent
- Dizziness -- up to 2 percent.
In children, the most common side effects included:
- Headaches -- in up to 14 percent of children
- Sore throat -- up to 6.2 percent
- Abdominal pain (stomach pain) -- up to 5.6 percent
- Cough -- up to 4.4 percent
- Drowsiness -- up to 4.2 percent
- Nosebleeds -- up to 3.7 percent
- Diarrhea -- up to 3.1 percent.