Serious side effects of Claritin include fast or uneven heart rate, yellowing of the skin or eyes, seizures or convulsions, and feeling faint, states RxList. Signs of a rare, life-threatening allergic reaction to Claritin include difficulty breathing, hives, and swelling of the lips, tongue, throat or face.
Common, less serious side effects of Claritin include headache, stomach pain, blurred vision, feeling drowsy or tired, and rash according to RxList. Pregnant and nursing women and children under 6 should generally avoid using Claritin unless instructed by a doctor. Drug interactions occur with certain antifungal medications, antibiotics and acid-reducing drugs.
Claritin is an antihistamine that relieves allergy symptoms such as sneezing, runny nose, itching and allergic skin reactions, states RxList.