Increases Risk of CirrhosisMany studies show that people with chronic hepatitis C who drink alcohol have a higher chance of developing cirrhosis. There isn't agreement on how much alcohol will increase this risk, but it's possible that even small amounts will lead to more fibrosis (and extensive fibrosis leads to cirrhosis). Because of this relationship, most doctors advise that someone with chronic hepatitis C should completely avoid all types of alcoholic beverages (beer, wine, liquor).
Increases Number of Deaths from Chronic HepatitisSeveral studies show that people who abuse alcohol while chronically infected with hepatitis C are more likely to die than those who have hepatitis C and do not drink.
Increases Risk of Hepatocellular CarcinomaHepatocellular carcinoma (HCC) is a type of liver cancer that is a major complication of chronic hepatitis, especially from infections with hepatitis B and C viruses. Worldwide, liver cancer is common, and it's a leading cause of death in the United States. People with both alcoholic liver disease and hepatitis C have a higher chance of developing HCC than those with hepatitis C infection alone.
Decreases the Effectiveness of Treating with InterferonCurrently, taking a combination of two drugs, peginterferon and ribavirin, is the standard treatment for chronic hepatitis C. However, studies suggest that interferon therapy may not work as well in heavy drinkers, though this may be related to reduced compliance while drinking heavily. Because of this, it's recommended that people completely stop drinking before starting treatment.
Dienstag, JL. "Chronic Hepatitis." Harrison's Principles of Internal Medicine 17e. 2008.
Szabo G, Marshall CA, Chopra, S. Hepatitis C and Alcohol. UpToDate. Accessed: March 14, 2009.