The most severe toxicities result from IL-2's ability to increase capillary permeability. This may cause hypotension, ascites, generalized body edema, and pulmonary edema. Chills and fever also frequently occur within a few hours after IL-2 administration. Headache, malaise, and other flu-like symptoms are also common. Gastrointestinal effects include nausea, vomiting, loss of appetite, diarrhea, and mucositis.
Some liver dysfunction is common during therapy but resolves once treatment is stopped.
Central nervous system toxicity if manifested by lethargy, confusion, disorientation, and hallucination, anxiety, and sometimes depression. Although the effect of IL-2 on the kidneys is generally mild, renal failure can result if severe hypotension occurs. Hypotension, anemia, and a decrease in platelets are more likely with higher, cumulative doses. Skin changes include redness, rash, pruritus, and occasionally skin desquamation. Although many research studies with IL-2 require intensive supportive care in acute care settings, other current treatment regimens can be given on an outpatient basis.