Interferons: Effectiveness, Toxicities, and Costs

Phase I, II, and III trials that defined the therapeutic effectiveness of interferons for neoplastic, viral, and immunologic diseases have helped improve the quantity and quality of life for thousands of patients. Hematologic malignant conditions have been particularly responsive to interferon treatment, but solid tumors have also been treated successfully. Interferon treatment has also decreased the duration of the symptom phases in viral diseases of DNA and RNA virus origin and have decreased the number and duration of complications of these diseases. As the use of interferons has become more widespread and duration of treatment has increased, these agents themselves have been identified as potent modifiers of biological response. Like glucocorticoids, interferons result in unwanted side effects when given in pharmacologic doses.

From a patient's perspective, toxicities of interferons fall into two groups: 1) an acute complex of fever, chills, malaise, and arthralgias and 2) chronic constitutional effects of fatigue, anorexia, weight loss, depression, impaired cognitive function, and diminished sexual interest or function [1]. The acute toxicities primarily occur on the first or second day of administration and are rarely difficult to manage thereafter; the chronic side effects are more troublesome and may become dose limiting. Myelosuppression, although common, usually occurs as a nadir plateau, reverses within a few days of stopping therapy, and is rarely of clinical importance. Hepatotoxicity may be a serious side effect, but it occurs infrequently. These toxicities almost certainly represent an extension of the cellular effects of …