Your liver plays a key role in detoxifying harmful substances that you may eat, drink, inhale or rub on your skin. However, the liver is no match for certain toxins, including some common medications. Toxic hepatitis is liver inflammation that occurs when your liver is damaged by toxic chemicals, drugs or certain poisonous mushrooms.
In some cases, toxic hepatitis develops within hours or days of exposure to a toxin. In other cases, it may take months of regular use before symptoms of toxic hepatitis appear. Often, the symptoms clear when your exposure to the toxin stops. But toxic hepatitis can permanently injure your liver, leading to irreversible scarring of liver tissue (cirrhosis) and in some cases to liver failure.
Your liver performs hundreds of vital functions, including processing nutrients, regulating blood clotting and producing bile, a fluid that helps digest fats. It also removes most drugs and chemicals from your bloodstream, breaking them down so they can be quickly eliminated from your body. But the conversion of these toxins into a simpler form creates byproducts that can be highly damaging to the liver. Although
the liver has a great capacity for regeneration, constant exposure to toxic substances can cause serious — and sometimes irreversible — harm.
Toxins that damage the liver are divided into two broad groups :
- Toxins that always cause liver damage (direct toxins). Some toxins always damage the liver. Dry cleaning solvents and the aptly named deathcap (amanita) mushroom belong in this group. They contain poisons that overwhelm the liver's ability to process them, and the resulting toxic byproducts destroy liver cells. If enough cells are destroyed, the liver can no longer function (liver failure).
- Toxins that may cause liver damage (idiosyncratic toxins). Other toxins cause liver damage in only a small percentage of people. Why certain substances lead to toxic hepatitis in some people but not in others isn't entirely clear.
You don't have to look farther than your medicine cabinet to find the majority of liver toxins. Nonprescription pain relievers such as aspirin, ibuprofen (Advil, Motrin, others), naproxen (Aleve), and acetaminophen (Tylenol, others) can all damage your liver, especially if taken frequently or combined with alcohol.
In theory, all prescription drugs can injure the liver. Many don't cause serious harm, but hundreds may, including :
- Halothane. Inhaled anesthetics such as halothane can cause severe liver damage, especially after repeated exposure. Women are twice as likely to experience halothane hepatoxicity as men are. People who are overweight also are at high risk.
- Isoniazid. This common tuberculosis drug can cause hepatitis after only a month or two of treatment, especially in people age 50 and older.
- Valproic acid and phenytoin. These anti-seizure medications have been known to cause toxic hepatitis and liver failure.
- Methotrexate. This cancer drug, which is also used to treat psoriasis and rheumatoid arthritis, can damage the liver. Taking folic acid along with methotrexate may offset some of the drug's toxic effects.
- Statins. The entire family of cholesterol-lowering drugs, which includes atorvastatin (Lipitor), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), fluvastatin (Lescol) and rosuvastatin (Crestor), can damage your liver.
- Some high-blood pressure medications. High blood pressure medications that can damage the liver include calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors.
- Ketoconazole. This common antifungal medication can cause toxic hepatitis and shouldn't be taken by anyone with liver problems.
- Antibiotics. A wide range of antibiotics can injure the liver.
- Anabolic steroids. These now-notorious drugs cause liver inflammation by interfering with the flow of bile.
Herbs: Not always your cup of tea
Some herbs, such as milk thistle, may help heal the liver, but others can cause liver damage. Herbs can also interact with prescription drugs, leading to more serious side effects than either alone would cause.
Some of the herbs considered dangerous to the liver include :
You usually must take herbs or medications for a period of time before liver damage occurs. But certain chemicals are different. Some are so toxic that a single unprotected exposure can cause liver failure. The United States government has identified 20 industrial chemicals that can cause acute liver injury or death, and more than 150 others that may lead to toxic hepatitis following longer exposure. Among the most common are carbon tetrachloride, a dry cleaning solvent; the industrial toxin trichloroethylene; and the herbicide paraquat.
Risk Factor :
Taking over-the-counter pain relievers or certain prescription drugs, especially for an extended time or in higher-than-recommended amounts, is probably the single biggest risk factor for toxic hepatitis. Your risk increases if you :
- Have another liver disease. Having a serious liver disorder such as cirrhosis or fatty liver disease makes you much more susceptible to the effects of toxins.
- Have viral hepatitis. If you have viral hepatitis — such as hepatitis A, B or C — and take even normal doses of acetaminophen, you have a greatly increased risk of developing toxic hepatitis.
- Are an older adult. As you age, your liver breaks down harmful substances more slowly. This means that toxins and their byproducts stay in your body longer.
- Drink alcohol. Combining medications with even moderate amounts of alcohol — no more than two drinks a day for men or one for women — significantly increases the toxic effects of most drugs. Heavy drinkers who take acetaminophen even at recommended doses are at risk of acute liver failure.
- Are female. Because women seem to metabolize certain toxins more slowly than men do, their livers are exposed to higher blood concentrations of harmful substances for longer periods of time.
- Have certain gene defects. Inheriting certain defects in the liver enzymes that break down toxins may make you more susceptible to toxic hepatitis.
- Are exposed to industrial toxins. Working with certain industrial chemicals puts you at risk of toxic hepatitis.
When to seek medical advice :
See your doctor right away if you develop any of the signs or symptoms of toxic hepatitis, including jaundice and fatigue. Get immediate medical care if you or a child develops signs of a possible acetaminophen overdose, such as :
- Nausea and vomiting
Call 911, your local emergency services or the poison control center at 800-222-1222. An acetaminophen overdose can be fatal if not treated quickly.
Mild forms of toxic hepatitis may not cause any noticeable problems and may be detected only by blood tests. When signs and symptoms occur, they're similar to those caused by other types of hepatitis :
- Yellowing of the skin and whites of the eyes (jaundice)
- Loss of appetite
- Nausea and vomiting
- Weight loss
- Dark or tea-colored urine
To diagnose toxic hepatitis, your doctor will likely perform a physical exam and take a complete medical history. Be sure to bring all medications you're taking, including over-the-counter drugs and herbs, in their original containers to your appointment. Tell your doctor if you work with industrial chemicals, or may have been exposed to pesticides, herbicides or other environmental toxins such as polychlorinated biphenyls (PCBs).
There are no tests for toxic hepatitis, but blood tests that look for high levels of certain liver enzymes and a liver biopsy can help confirm the diagnosis. In a liver biopsy, a small sample of tissue is removed from your liver and examined under a microscope. Your doctor uses a thin needle to obtain the sample. Needle biopsies are relatively simple procedures requiring only local anesthesia. Risks include bruising, bleeding and infection.
If you're taking medications known to cause liver problems, your doctor may want to check your liver at least once every six months. Some types of liver damage can be reversed if treated promptly.
Like other types of hepatitis, toxic hepatitis can cause serious complications including :
- Increased blood pressure in the portal vein. Blood from your intestine, spleen and pancreas enters your liver through a large blood vessel called the portal vein. If damaged liver tissue blocks normal circulation through the liver, the blood backs up, leading to increased pressure within this vein (portal hypertension). This, in turn, causes blood to back up into other blood vessels in your stomach, esophagus and lower intestine.
- Enlarged veins (varices). When circulation through the portal vein is blocked, blood may back up into other blood vessels in the stomach, esophagus and lower intestinal tract. These blood vessels are thin-walled, and because they're filled with more blood than they're meant to carry, are likely to leak. Massive bleeding in the upper stomach or esophagus from these blood vessels is a life-threatening emergency that requires immediate medical care.
- Jaundice. This occurs when your liver isn't able to remove bilirubin — the residue of old red blood cells — from your blood. Eventually, bilirubin builds up and is deposited in your skin and the whites of your eyes, causing a yellow color.
- Cirrhosis. This serious condition — irreversible scarring of the liver — is a leading cause of death in Americans ages 45 to 54. Cirrhosis frequently leads to liver failure, which occurs when the liver is no longer able to function.
No specific treatment exists for most kinds of toxic hepatitis. Acute acetaminophen overdose is an exception — the chemical acetylcysteine is an effective antidote if given within 24 hours of the overdose. The sooner the medication is administered, the better the outcome. For most other cases of drug-induced toxic hepatitis, stopping the medication is the only treatment. Some people improve quickly once they're no longer exposed to the drug, especially if the problem is caught early. For others, recovery may take months.
Other treatments include :
- Supportive therapy. People with severe symptoms are likely to receive supportive therapy in the hospital, including intravenous fluids and medication to relieve nausea and vomiting.
- Liver transplant. When liver function is severely impaired, a liver transplant may be the only option for some people. Although liver transplantation is often successful, the number of people awaiting transplants far exceeds the number of donated organs.
Because it's not possible to know how you'll react to a particular medication, toxic hepatitis can't always be prevented. But these steps can help reduce your risk :
- Limit medications. Take prescription and nonprescription drugs only when absolutely necessary. Investigate nondrug options for common problems such as high blood pressure, high cholesterol and arthritis pain.
- Take medications only as directed. Follow the directions exactly for any drug you take. Don't exceed the recommended amount, even if your symptoms don't seem to improve. Because the effects of over-the-counter pain relievers wear off quickly, it's easy to take too much. Most nonprescription drugs also have what's known as a "ceiling effect," which means that higher doses won't produce better results.
- Be cautious with herbs and supplements. Don't assume that a natural product won't cause harm. Acute liver failure in children can occur after taking as few as five adult-strength multiple vitamins with iron. Look for reliable information on herbs before using them.
- Don't mix alcohol and drugs. Alcohol and medications are a bad combination. If you're taking acetaminophen, don't drink. Ask your doctor or pharmacist about the interaction between alcohol and other prescription and nonprescription drugs you use.
- Take precautions with chemicals. If you work with or use hazardous chemicals, take all necessary precautions to protect yourself from exposure. If you do come in contact with a harmful substance, follow the guidelines in your workplace, or call your local emergency services or the poison control center for help.
- Protect children. Keep all medications and vitamin supplements in child-proof containers so that children can't accidentally swallow them. Adult medications that are particularly dangerous for children include diet pills, antidepressants, high blood pressure pills and iron supplements.