Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
wheezing, choking, or other breathing problems after using  umeclidinium and vilanterol;
painful or difficult urination, or urinating more often;
blurred vision, tunnel vision, eye pain or redness, or seeing halos around lights;
high blood sugar--increased thirst or urination, hunger, dry mouth, fruity breath odor; or
low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, numbness or tingling, muscle weakness or limp feeling.
Common side effects may include:
stuffy nose, sinus pain, sore throat;
chest pain, cough;
diarrhea, constipation;
muscle spasms; or
pain in your neck, arms, or legs.
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.
 Umeclidinium/vilanterol side effects (more detail)
