Idelalisib, which is also sold under the brand name “Zydelig”, is a medication that is typically taken by mouth, and is used in combination with rituximab to treat relapsed chronic lymphocytic leukemia. This drug is also indicated for the treatment of follicular B-cell non-Hodgkin lymphoma and relapsed small lymphocytic lymphoma, “both in patients who have received at least two prior systemic therapies” (Wikipedia.com). It is worth noting that this medication comes in the form of a tablet, and is taken twice daily (with or without food). As for the common side effects of Idelalisib, chemocare.com lists the following: Hypertriglyceridemia, Hyperglycemia, Neutrophil count decreased, and fever. There are also other side effects that are less common such as abdominal pain, nausea, diarrhea, pneumonia, fatigue, rash, and chills. When it comes to the severe side effects of this drug, they include liver problems, severe diarrhea, and breathing problems. It is recommended that you tell your doctor if you are pregnant or plan on becoming pregnant prior to taking Idelalisib as it may be hazardous to the fetus.