Get emergency medical help if you have signs of an allergic reaction to loratadine: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using loratadine and call your doctor at once if you have:
fast or uneven heart rate;
severe headache; or
a light-headed feeling, like you might pass out;
Common loratadine side effects may include:
headache;
feeling tired or drowsy;
stomach pain, vomiting;
dry mouth; or
feeling nervous or hyperactive.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Loratadine side effects (more detail)
