Hepatitis - Introduction

Hepatitis Caused by Alcohol and Drugs

Alcohol. About 10% to 35% of heavy drinkers develop alcoholic hepatitis. In the body, alcohol breaks down into various chemicals, some of which are very toxic in the liver. After years of drinking, liver damage can be very severe, leading to cirrhosis in about 10% to 20% of cases. Although heavy drinking itself is the major risk factor for alcoholic hepatitis, genetic factors may play a role in increasing a person's risk for alcoholic hepatitis. Women who abuse alcohol are at higher risk for alcoholic hepatitis and cirrhosis than are men who drink heavily. High-fat diets may also increase the risk in heavy drinkers.

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Drugs. Because the liver plays such a major role in metabolizing drugs, hundreds of medications can cause reactions that are similar to those of acute viral hepatitis. Symptoms can appear anywhere from two weeks to six months after starting drug treatment. In most cases, they disappear when the drug is withdrawn; but, in rare circumstances, they may progress to serious liver disease. Among the drugs most prominently cited for liver interactions are halothane, isoniazid, methyldopa, phenytoin, valproic acid, and the sulfonamide drugs. Notably, very high doses of acetaminophen (Tylenol) have been known to cause severe liver damage and even death, particularly when used with alcohol.

Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) affects between 10% and 24% of the population covers a number of conditions, notably nonalcoholic steatohepatitis (NASH). NAFLD has features similar to alcohol- induced hepatitis, particularly a fatty liver, but it occurs in individuals who do not consume significant amounts of alcohol. Severe obesity and diabetes are the major risk factors and may pose a risk for more severe conditions. NAFLD may also occur in conjunction with small intestine surgery or other factors.

NAFLD is usually benign and very slowly progressive. In certain patients, however, it can lead to cirrhosis, liver failure, or liver cancer.

Weight reduction and management of any accompanying medical condition are the primary approaches to nonalcoholic fatty liver disease. To date, however, there is no effective treatment for NAFLD. Drugs, such as fibrates, used to lower triglycerides or those that increase insulin levels, such as metformin, may help protect against liver damage. Other drugs showing some promise include ursodiol and betaine. Vitamin E may help reduce liver injury.