What side effects may I notice from receiving Zafirlukast?

Side effects that you should report to your doctor or health care professional as soon as possible:
-allergic reactions like skin rash or hives, or swelling of the face, lips, or tongue
-breathing problems
-chest pain or irregular heartbeat
-dark urine
-infection
-general ill feeling or flu-like symptoms
-hallucinations
-light-colored stools
-loss of appetite, nausea
-pain and swelling of your sinuses
-right upper belly pain
-pain, tingling, numbness in the hands or feet
-suicidal thoughts or other mood changes
-unusually weak or tired
-yellowing of the skin or eyes

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
-bleeding or bruising
-diarrhea
-dizziness
-headache
-stomach upset
-trouble sleeping

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