One of the hazards of fibromyalgia is liver toxicity. Not from the fibromyalgia itself, but from the medications we take. The liver’s most important task is to filter toxic substances from your body. Drugs and other toxins place added stress on the liver’s filtering function. This includes prescription and over-the-counter medications, vitamins, herbal supplements, hormones, “recreational drugs” and environmental toxins.
The risk of drug-induced liver toxicity is higher for women, especially when taking multiple long-term medications. Many of us with fibromyalgia and other chronic illnesses are taking multiple medications. And many also take multiple herbal supplements. The more drugs you take, the longer you use them, the higher the risk of liver damage.
Acetaminophen (Tylenol) is the most well-known medication that causes liver toxicity. Nonsteroidal anti-inflammatory drugs (NSAIDs), some antidepressants, cholesterol-lowing medications and many others can potentially damage the liver.
In fact, there are over 1000 medications and herbal supplements that have been implicated in the development of drug-induced liver toxicity.
How Drugs Induce Liver Toxicity
Damage or injury to the liver caused by a drug, chemical or another agent is called hepatotoxicity. Liver toxicity is also referred to as drug-induced liver injury (DILI). Drugs cause damage to the liver in several ways. Some drugs deliver toxins directly to the liver. Other drugs are transformed by the liver to chemicals that cause injury to the liver directly or indirectly.
There are three types of liver toxicity:
- Dose-dependent Toxicity – Drugs that cause dose-dependent toxicity can cause liver damage in most people if enough of the drug is taken. The most well-known dose-dependent toxicity example is acetaminophen (Tylenol) overdose.
- Idiosyncratic Toxicity – Drugs that cause idiosyncratic toxicity cause disease in only people that have inherited genes that control the chemical transformation of that specific type of drug. Even though the risk of developing drug-induced idiosyncratic liver toxicity is low, it is the most common form of drug-induced liver toxicity. That is because it is hard to detect in drug clinical trials and will only surface after millions of people begin to use the FDA approved drug.
- Drug Allergy – Drug allergy is uncommon. In drug allergy, the liver is damaged by inflammation that occurs when the body’s immune system attacks the drug with antibodies.
In many cases, once the offending drug is stopped the liver will recover, but not always. More than 75 percent of idiosyncratic drug reactions result in liver transplantation or death.
The U.S. Food and Drug Administration reports that: in the United States, drug-induced liver injury (DILI) is now the leading cause of acute liver failure (ALF), exceeding all other causes combined. Drug-induced liver toxicity accounts for 2-5% of cases of patients hospitalized with jaundice and approximately 10% of all cases of acute hepatitis.
Signs Of Liver Toxicity
When drugs injure the liver and disrupt its normal function, signs of liver disease develop. Symptoms of drug-induced liver diseases are similar to those of liver diseases due to other causes such as viruses and immunological diseases.
These are the types of liver disease drugs can cause:
- Elevated Liver Enzymes – Many drugs cause mild elevations in blood levels of liver enzymes without symptoms or signs of liver disease. Drugs that commonly cause elevations of liver enzymes include aspirin, statins (used in treating high blood cholesterol levels) some antibiotics, some antidepressants and some medications used for treating diabetes. Typically, these abnormal levels will become normal shortly after stopping the drug, and there usually is no long-term liver damage.
- Hepatitis – Some drugs can cause acute and chronic hepatitis (inflammation of liver cells). Acute drug-induced hepatitis is the most common and is defined as hepatitis that lasts less than 3 months. Chronic hepatitis lasts longer than 3 months. Symptoms of drug-induced hepatitis include loss of appetite, nausea, vomiting, fever, fatigue, weakness and abdominal pain. In more serious cases, patients can develop dark urine, fever, light-colored stool, and jaundice (a yellowing of the skin and whites of the eyes). Both acute and chronic hepatitis typically resolve after stopping the drug, but sometimes acute hepatitis can be severe enough to cause acute liver failure and chronic hepatitis can on rare occasions, lead to permanent liver damage.
- Necrosis – Chronic liver diseases such as hepatitis, fatty liver, or cholestasis can lead to the necrosis (death) of liver cells. It is often is caused by more severe hepatitis. Liver necrosis occurs when large portions of your liver die off due to severe liver disease, and it generally leads to liver failure.
- Cholestasis – With cholestasis, the secretion and/or flow of bile is reduced. The main symptoms are itching and jaundice. Most people with drug-induced cholestasis will recover fully within weeks after stopping the drug, but in some, jaundice, itching, and abnormal liver tests can last months after stopping the drug.
- Steatosis – Fatty Liver Disease is the accumulation of fat in the liver. The most common causes are alcoholism and non-alcoholic fatty liver disease (NAFLD) associated with obesity and diabetes. Often there are no symptoms. There are typically mild to moderate elevations in blood levels, and the liver may become enlarged. Drugs may cause fatty liver with or without associated hepatitis. In severe cases, drug-induced fatty liver can lead to cirrhosis and liver failure.
- Cirrhosis – Advanced scarring of the liver as a result of chronic hepatitis, cholestasis, or fatty liver. The most common example of drug-induced cirrhosis is alcoholic cirrhosis. The liver damage done by cirrhosis can’t be undone. But if liver cirrhosis is diagnosed early and the cause is treated, further damage can be limited. As cirrhosis progresses, more and more scar tissue forms. The scarring makes it difficult for the liver to function. Advanced cirrhosis is life-threatening.
- Mixed disease – A combination of more than one liver disease, for example, both hepatitis and necrosis of liver cells, hepatitis and fatty liver, or cholestasis and hepatitis.
- Fulminant Hepatitis – Severe, life-threatening liver failure. The patient is extremely ill with the symptoms of acute hepatitis with additional problems of confusion or coma and bruising or bleeding. In the U. S., acetaminophen (Tylenol) is the most common cause of acute liver failure. 70% to 90% of people with fulminant hepatitis die.
- Blood Clots – Certain drugs can cause blood clots to form in the veins of the liver. This can lead to an enlarged liver, abdominal pain, fluid collection in the abdomen, and liver failure.
The diagnosis of drug-induced liver diseases may often be missed. Symptoms may be mild and nonspecific. The person may be taking multiple drugs, which makes it difficult to identify the offending drug. There may also be other potential causes of liver diseases such as non-alcoholic fatty liver disease and alcoholism.
What Can You Do To Protect Your Liver?
Liver toxicity is the most frequent reason for drugs either not receiving FDA approval or being withdrawn from the market. When the Food and Drug Administration approves a medication for use by the general public, less than half of the serious drug reactions are known.
Dietary supplements can also cause liver damage. Dietary supplement manufacturers and distributors are not required to obtain approval from FDA before marketing dietary supplements. Also, dietary supplements are not put through the same strict safety and effectiveness requirements as conventional drug products. Therefore, the FDA does not ensure potency or purity of the ingredients in dietary supplements. That is up to the manufacturer.
Remember, a drug is a drug, whether it is a medication or a dietary supplement. Here are some tips to avoid drug-induced liver toxicity:
- Always keep a list of all the prescription and non-prescription medications that you take, including herbs, vitamins, and supplements. Bring this list with you to every medical appointment.
- Inform your doctor of all medications (prescription and over-the-counter), dietary supplements, and herbal remedies that you take and ask if there are any potential interactions. If you have several physicians prescribing medications for you, be sure all of them are updated on your current list of medications.
- Get all your prescriptions filled at the same pharmacy. Keeping a record of all your medications in one place will enable your pharmacist to identify potential interactions that may occur between your medications.
- Notify your doctor immediately if you experience any unexpected side effects from a prescription or over-the-counter medication.
- When prescribed a new medication, ask your doctor or pharmacist if the medication has any potential side effects for the liver.
- Consider taking a liver supplement containing milk thistle. Studies have shown that milk thistle can help prevent liver injury from drugs and other toxins. Milk thistle is a herb, which has been used for centuries as a treatment of liver conditions. It is widely used for acute and chronic liver diseases.
Do Your Own Research. The National Institute of Health maintains a database of prescription and nonprescription medications, herbals and dietary supplements associated with drug-induced liver injury. Search the LIVERTOX DATABASE to see if anything you are taking is known to cause liver toxicity.
Some experts recommend only taking a drug after it’s been on the market for seven years.
Pre-Existing Liver Disease
Medications that are known to be toxic to people with a pre-existing liver disease usually carry a warning regarding its use in people with liver problems. In most cases, people who have a mild liver disease can safely take most common prescription and non-prescription medications at the recommended dose.
Having mild liver disease does not increase the risk that a given medication will be toxic to the liver. However, if a person with pre-existing liver disease happens to develop liver injury from a medication, the resulting liver damage may be more severe than would occur in a healthy person with the same reaction.
No drug is risk-free. Liver toxicity can be caused from prescriptions, over-the-counter medications, vitamins, herbal supplements, hormones, “recreational drugs” and environmental toxins. The risk of drug-induced liver toxicity is higher in women. Age, genetics, pre-existing medical conditions, using multiple drugs and alcohol consumption can increase those risks.
Over 1000 medications and herbal supplements have been implicated in the development of drug-induced liver toxicity. It’s important to know which medications can cause liver damage, which will worsen a pre-existing liver condition, and which medications are safe to take.