Get emergency medical help if you have signs of an allergic reaction to Zydelig (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.
Zydelig can cause serious harm to your liver, lungs, or intestines. You may have severe or life-threatening diarrhea, or a perforation (a hole or tear) in your intestines. Some of these conditions may lead to fatal complications.
Call your doctor at once if you have:
severe diarrhea, increased number of stools per day;
easy bruising, unusual bleeding, purple or red spots under your skin;
intestinal problems - worsening stomach pain, fever, chills, vomiting;
liver problems - upper stomach pain, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);
lung problems - worsening cough, wheezing, cough with mucus, or shortness of breath;
low white blood cell counts - fever, mouth sores, skin sores, sore throat.
Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.
Common Zydelig side effects may include:
nausea, stomach pain, diarrhea;
fever, cough, lung problems;
low white blood cells;
abnormal liver function tests;
rash; or
feeling tired.
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.
 Zydelig side effects (more detail)
