Interferon Side Effects

Activated immune cells normally produce proteins called interferons. The various forms of naturally occurring interferon help coordinate the immune system defenses and may act directly against invading germs or tumor cells. Medicinal interferons are highly concentrated, synthetic versions of naturally occurring interferons. Physicians prescribe medicinal interferons for the treatment of a variety of diseases, including multiple sclerosis, chronic hepatitis B and C, melanoma, Kaposi sarcoma and certain types of leukemia and lymphoma. Interferon commonly causes side effects, which range from mild to severe.

Depression

Depression occurs in a significant number of patients treated with interferon, according to the National Library of Medicine pharmaceutical website Daily Med. In a 2009 article published in Dialogues in Clinical Neuroscience, psychiatrist Francis Lotrich of the University of Pittsburgh Medical Center says that approximately 15 to 40 percent of patients taking interferon-alpha for chronic hepatitis C experience major depression. Sleep quality, a history of previous episodes of depression, the availability of social support and certain genetic factors influence the risk for interferon-induced depression, Lotrich says.

Flu-like Symptoms

Treatment with interferon commonly leads to flu-like symptoms. This side effect mimics the action of naturally occurring interferon. The generalized symptoms associated with viral infections, such as influenza, arise primarily due to immune-system production of interferons. Common flu-like symptoms associated with interferon therapy include fatigue, muscle and joint aches, low-grade fever and headaches, says Daily Med. The severity of these symptoms varies from mild to debilitating.

Decreased Appetite and Weight Loss

Patients on interferon therapy may experience decreased appetite. In some patients, weight loss occurs. According to Daily Med, approximately 17 to 27 percent of patients on interferon-alpha therapy experience loss of appetite. Weight loss occurs in approximately 3 to 10 percent of patients. Decreased appetite and weight loss occur infrequently among patients on interferon-beta therapy.

Skin Rashes

Skin rashes may develop in patients on interferon therapy, according to MayoClinic.com. Itching may accompany skin rash in some patients. Hives may also occur. Because skin rashes commonly develop for reasons other than a medication side effect, the treating doctor examines any new skin rash that develops while on interferon therapy to determine the cause.

Temporary Hair Loss

Temporary hair loss may occur in patients on interferon therapy, says Daily Med. Most patients with this side effect experience mild to moderate thinning of the hair. Regrowth of the hair typically occurs after the completion of treatment. Temporary hair loss occurs more commonly with interferon-alpha, compared to interferon-beta, according to the manufacturer's prescribing information.