Liver disease: How medications can harm the liver

By Mayo Clinic Staff

Your liver plays a key role in processing medications and removing them from your body. But when the liver is injured or not working properly, it can't process medicines as well. As a result, medications can build up in the body, side effects may become stronger, and some medicines may even cause further liver damage.

Knowing how liver disease affects medication use — and how certain medicines can harm the liver — can help you take medicines safely.

How medications can harm the liver

Liver disease can change the way your body handles medications in several ways:

• Slower processing. The liver uses enzymes to break down medicines. When the liver isn't working well, this process slows down. Medicines can stay in your body longer than they should.
• More medications reach the bloodstream. When you take a pill, the medicine is partly filtered by the liver before it reaches the rest of the body. This is called first-pass metabolism. In liver disease, more of the medicine may bypass this step, allowing more of the medicine to go directly into your system. This can make the medicine stronger or last longer.
• Changes in how medicine travels through the body. Medications often attach to proteins in the blood, such as albumin. A damaged liver may make less albumin, leaving more free, also known as unattached, medicine in the blood. This can increase side effects.
• Problems getting rid of medications. The liver and kidneys work together to remove medicines from the body. If the liver isn't working well, medicine may build up and cause harm.

Because of these changes, people with liver disease are at a higher risk of medication-related side effects and drug interactions. And people who don't have liver disease are at risk of a condition called drug-induced liver injury (DILI).

Drug-induced liver injury

When the liver is damaged by a medicine or supplement, it's called drug-induced liver injury (DILI), also known as toxic hepatitis. DILI can range from mild, temporary changes to serious damage and even acute liver failure.

More than 1,000 types of drugs have been linked to liver injury.

These include prescription medicines, medicines available without a prescription and herbal supplements.

Pain relievers

Some common pain relievers can harm the liver.

Nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Advil, Motrin) and naproxen sodium (Aleve) can damage the liver, especially when used often or with alcohol. These medicines should usually be avoided by people with liver disease or those who have had a liver transplant.

Acetaminophen (Tylenol) is considered safe at proper doses. But it is very dangerous in overdose. In fact, overdose is the most common cause of acute liver failure. Acetaminophen is in more than 600 medicines, so always check labels for "acetaminophen," "acetam" or "APAP."

For people with chronic liver disease, less than 2 grams a day, in divided doses, is generally considered safe. Always ask your healthcare team before taking any amount. Acetaminophen is generally safer than an NSAID for people with liver disease when used correctly.

Prescription medicines

Many prescription medicines are linked to liver injury. Some common examples include:

• Antibiotics such as amoxicillin-clavulanate (Augmentin).
• Antiseizure medicines such as phenytoin (Dilantin, Phenytek).
• The immunosuppressant medicine azathioprine (Azasan, Imuran).
• Niacin (Niacor).
• The antifungal medicine ketoconazole.
• Certain antiviral medicines.
• Anabolic steroids.

Other prescription medicines can be more dangerous, specifically in people who already have liver disease. These include:

• Opioids such as oxycodone, tramadol, morphine and others: In people with cirrhosis, these drugs can increase the risk of hepatic encephalopathy. This is a serious condition that occurs when the liver is not able to filter toxins from the blood. The buildup of toxins affects the brain's ability to function.
• Proton pump inhibitors such as pantoprazole, rabeprazole, omeprazole and others: These medications may increase infection risk in people with cirrhosis.
• Cancer immunotherapy medications, also called immune checkpoint inhibitors: These medicines include isoniazid, methotrexate, nitrofurantoin, rifampin, tamoxifen and others. They can raise liver enzyme levels.
• Diabetes medications such as glyburide, glipizide and pioglitazone: People who have advanced cirrhosis due to risk of low blood sugar should avoid taking these medicines.

Herbs and supplements

Some herbs and supplements can harm the liver or make liver disease worse. In fact, in the United States, roughly 20% of drug-induced liver injury cases are caused by herbal products.

While not everyone taking herbs and supplements will have liver injury, the risk is higher — especially if you already have liver disease. Talk with your healthcare team before taking any new supplement or herbal remedy to be sure it's safe for you.

Watch out for these herbs and supplements:

• Aloe vera.
• Ayurvedic herbs.
• Black cohosh.
• Cascara.
• Cassia seed.
• Chaparral.
• Germander.
• Greater celandine.
• Kava kava.
• Kratom.
• Ma-Huang, also called ephedra.
• Mistletoe.
• Mentha, especially pennyroyal oil.
• Polygonum multiflorum.
• Skullcap.
• Valerian.
• Green tea extract.
• Turmeric supplements.

Review medications and supplements with your healthcare team

If you have liver disease, it's especially important to talk with your healthcare team about all the medicines you take — including prescription medications, medicines available without a prescription, vitamins and supplements.

If you need allergy or cold medicine, ask your healthcare team or pharmacist which products are safest for your liver. Many allergy or cold medicines contain NSAIDs or acetaminophen, so it's important to read labels to understand what you're taking.

Only take medications recommended by your care team, and always follow the dosing instructions carefully. Tell your team about everything you take, even if it seems harmless or natural. Avoid starting any new medicine or supplement without checking with your care team first.

Keep an up-to-date list of all your prescription and nonprescription medicines, vitamins, and supplements, and share it with your healthcare team at every visit.