Get emergency medical help if you have signs of an allergic reaction to oxybutynin: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using this medicine and call your doctor at once if you have:
severe stomach pain or constipation;
blurred vision, tunnel vision, eye pain, or seeing halos around lights;
little or no urination;
painful or difficult urination; o
dehydration symptoms--feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin;
Side effects such as dry mouth, constipation, and confusion may be more likely in older adults.
Common oxybutynin side effects may include:
dizziness, drowsiness;
blurred vision;
dry mouth; or
diarrhea, constipation.
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.
 Oxybutynin side effects (more detail)
