What side effects may I notice from receiving Allegra Allergy 12 Hour ?

Side effects that you should report to your doctor or health care professional as soon as possible:
-allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
-breathing problems
-chest pain
-fast heartbeat
-infection or fever

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
-cough
-drowsiness
-dry or irritated nose, mouth, or throat
-headache
-menstrual changes
-pain
-stomach upset, nausea

This list may not describe all possible side effects for Allegra Allergy 12 Hour . Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.