What is Interferon?:
- Interferon is a mixture of proteins that our body makes in response to virus infections. Interferon has antiviral and immunomodulating effects.
- Interferons may be divided into alfa, beta, and gamma interferons.
- Intron and Roferon are made by genetic engineering and consist of one type of alfa interferon only.
- Infergen is genetically engineered also, but has a mix of different alpha interferons.
- Wellferon is made by cultured cells and contains a mixture of all naturally made alfa interferons.
How is Interferon Administered?:
- Usually administered as a subcutaneous injection (just underneath the skin) daily or three times per week. The dose regimen for intron and roferon is usually 3 million units three times per week for 1 year.
- Infergen is usually administered in doses of 9mcg - 15mcg three times per week.
- New preparations of intron and roferon (pegylated interferons) that can be administered once per week are now becoming available.
Who May Benefit from Interferon Treatment?:
- Patients with chronic hepatitis C - with markers of active infection: hepatitis C virus RNA positive and evidence of active liver disease - abnormal liver enzymes.
- Decision to treat should be made based on: likelihood of developing cirrhosis, likelihood of response, and presence of other medical problems that may impact on life expectancy or tolerance to treatment.
Hepatitis C Signs and Symptoms
When Should Interferon Not Be Used?:
- Patients with no evidence of virus multiplication (hepatitis C virus RNA negative) or active liver disease (normal liver enzymes.
- Patients with advanced cirrhosis.
- Patients with other major medical problems or emotional or psychiatric illnesses.
How Effective is Interferon?:
- Response is usually assessed by loss of hepatitis C virus RNA and normalization of liver enzymes.
- Approximately 20-50% of patients will respond during treatment but many patients relapse after treatment is stopped.
- Only 10-20% will have a sustained response after a 1 year course.
- Patients with HCV genotypes 2 or 3, those with low HCV RNA levels, and those with no cirrhosis are more likely to respond.
- Most (90%) responders maintain their response during long-term follow-up.
What Are the Side Effects of Interferon?:
- "flu-like" symptoms
- fever
- chills
- headache
- body aches
- fatigue
- these side effects usually go away after the first 1-2 weeks.
- decreased appetite
- weight loss
- insomnia
- hair loss (usually mild and reversible)
- decreased white blood cells and platelets
- Anxiety, mood changes, irritability, depression, difficulty concentrating, impaired memory
