—We agree with Drs Cribb, Renton, and Armstrong's point that interferon may suppress hepatic cytochrome P-450—dependent drug metabolism and that this interaction may increase the possibility of adverse drug events in patients treated with interferon.Since submission of our review, another possible adverse result of interferon therapy has also been reported: the development of autoimmunity (eg, antinuclear antibodies and autoimmune thyroid disease).1 Therefore, patients receiving interferon therapy should be monitored for development of autoantibodies, and interferon should be used only with great caution in patients with pre-existing autoimmune diseases.
Baron S, Tyring SK. Interferons: Potential Problems-Reply. JAMA. 1992;267(4):509. doi:10.1001/jama.1992.03480040056023