Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using olopatadine nasal and call your doctor at once if you have a serious side effect such as:
nosebleed;
sores inside your nose;
fever; or
burning or pain when you urinate.
Less serious side effects may include:
drowsiness;
a bitter taste in your mouth;
headache;
dry mouth, sore throat;
cough, sneezing, runny nose, cold symptoms;
weight gain; or
nausea, diarrhea, stomach pain.
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.
 Olopatadine nasal side effects (more detail)
