Common Cetirizine Side Effects
Cetirizine 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 cetirizine 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.
Less Common Cetirizine Side Effects
Rare cetirizine side effects occur in less than 2 percent of people taking the drug. Because these side effects are so uncommon, it is difficult to tell whether they are caused by cetirizine or something else.
These less common side effects include but are not limited to: