Biologic response modifiers: the interferon alfa experience.

The effects and toxicities of interferon alfa are described, and the role of the pharmacist in making decisions and providing education about biologic response modifiers (BRMs) is discussed. Interferons have both direct antitumor activity and extensive effects on the immune system. Two recombinant interferon alfa products--interferon alfa-2a and interferon alfa-2b are available commercially. Indications in FDA-approved labeling for interferon alfa include the treatment of hairy-cell leukemia, acquired immunodeficiency syndrome-related Kaposi's sarcoma, and genital warts; however, it also is being used successfully against early chronic myelogenous leukemia, low-grade non-Hodgkin's lymphoma, cutaneous T-cell lymphoma, and previously untreated multiple myeloma. Other malignancies that respond to treatment with interferon alfa are malignant melanoma, ovarian carcinoma, and renal cell carcinoma. The toxic pattern of interferon alfa consists of flu-like symptoms, which are seen at all doses, on all schedules, and in virtually all patients. After repeated dosing, the chronic toxicities of anorexia, weight loss, and malaise and fatigue may develop. Myelosuppression, central nervous system toxicity, increased hepatic enzyme concentrations, nausea and vomiting, and cardiovascular toxicity also are possible. Serum neutralizing antibodies may be formed during therapy; this phenomenon may affect the clinical outcome. Numerous BRMs are being investigated for clinical use, and pharmacists must become conversant in the issues that surround these agents. Areas in which pharmacist involvement and knowledge are important include overall cost, product similarities and differences, dosing and scheduling, drug delivery systems, ways to minimize waste, adverse effects and their management, drug interactions, storage requirements, differences in production and purification techniques among manufacturers, and education of patients and staff.(ABSTRACT TRUNCATED AT 250 WORDS)