Learn about the side effects of Children's Claritin Allergy (loratadine), from common to rare, for consumers and healthcare professionals.

Find patient medical information for Children's Claritin oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings.

Claritin and Claritin-D can also cause serious side effects. Call your child’s doctor or 911 right away if your child has any serious side effects, such as an allergic reaction.

Fatigue, or the general lack of energy, is a side effect of Claritin affecting around 3% of users. As with headaches, the side effects tend to be transient (short-term) and improve over time, although the feeling of tiredness and weakness can be profound in some people.