Epidiolex (cannabidiol) is a brand-name oral solution. It’s prescribed for adults and some children with certain seizure conditions. As with other drugs, Epidiolex can cause side effects, including liver problems and digestive problems.

Epidiolex can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Epidiolex in clinical trials:

Mild side effects can occur with Epidiolex use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Epidiolex’s prescribing information.

Mild side effects that have been reported with Epidiolex include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Epidiolex and want to tell the FDA about it, visit MedWatch.

Epidiolex may cause serious side effects. The following list may not include all possible serious side effects of the drug. For more information, you can refer to Epidiolex’s prescribing information.

If you develop serious side effects while taking Epidiolex, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

Epidiolex may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

How do side effects of Epidiolex compare with those of clobazam?

Epidiolex and clobazam (Onfi, Sympazan) are prescribed for seizures related to certain conditions. Specifically, either drug can be prescribed to treat a rare type of epilepsy called Lennox-Gastaut syndrome.

Both drugs can cause side effects such as sleepiness, insomnia, and vomiting. In addition, both drugs increase the risk of suicidal thoughts or behaviors.

Clobazam may cause other side effects that aren’t known to occur with Epidiolex. For example, clobazam has several boxed warnings. A boxed warning is the most serious warning from the FDA. For clobazam, these include:

Keep in mind that in some cases, Epidiolex and clobazam are taken together. This may increase the risk of certain side effects, such as liver problems. (For more details, see the “Side effect specifics” section.)

For more information about how Epidiolex’s side effects compare with clobazam’s, talk with your doctor or pharmacist.

Is Epidiolex safe for older adults?

Yes, Epidiolex is generally considered safe for older adults (ages 65 years and older).

However, older adults may be more likely to have certain health conditions that affect how their bodies respond to Epidiolex. For this reason, doctors may prescribe a lower dosage of Epidiolex for older adults than for younger people.

For details about whether Epidiolex is safe given your age, talk with your doctor or pharmacist.

Learn more about some of the side effects that Epidiolex may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Epidiolex.

Liver problems

High liver enzyme levels were common in clinical trials of Epidiolex. An increase in liver enzyme levels may be a sign of liver problems.

High liver enzyme levels may not cause symptoms but can be detected with a liver function test. Some other liver problems may cause loss of appetite, abdominal pain, and jaundice.

Certain factors may increase your risk of liver problems with Epidiolex. These include taking higher doses or taking Epidiolex with other medications that can cause liver problems, such as:

What you can do

Before starting treatment with Epidiolex, be sure to tell your doctor about any medications you take. They can advise whether it’s safe for you to take Epidiolex with these medications.

Your doctor will likely give you blood tests to check your liver enzyme levels before you start taking Epidiolex. They’ll continue to monitor your levels while you take the drug. Tell your doctor right away if you have symptoms of liver problems while taking Epidiolex.

If you have high liver enzymes or symptoms of liver problems, your doctor may lower your dosage of the drug.

Sedation

Sedation was a common side effect in clinical trials of Epidiolex. With sedation, you may feel calm, relaxed, or sleepy. This side effect usually occurs when you first start Epidiolex treatment. However, it typically eases as your body gets used to the drug.

Certain factors can increase your risk of sedation with Epidiolex. These include taking the drug with alcohol or certain other medications, such as benzodiazepines.

What you can do

Sedation with Epidiolex may lead to difficulties with thinking, coordination, or judgment. Due to this risk, it’s important to avoid driving after a dose until you know how Epidiolex affects you. It may take several doses before you know how the drug will affect you.

If you experience sedation during treatment that’s severe or bothersome, talk with your doctor. They can suggest other ways to manage this side effect.

Allergic reaction

As with most drugs, Epidiolex can cause an allergic reaction in some people. In clinical trials, this side effect wasn’t common.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Epidiolex. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Epidiolex. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

Liver problems. Before taking Epidiolex, tell your doctor if you have any liver problems, including liver disease and liver failure. Epidiolex can cause liver problems and may worsen any existing liver conditions. For this reason, your doctor may prescribe a lower dosage of Epidiolex if you have certain liver problems. This can help reduce your risk of side effects from the drug.

Also, taking certain drugs, such as valproate, clobazam, or both, with Epidiolex can increase ammonia levels and cause liver failure. If you take either of these drugs with Epidiolex and you have increased ammonia levels, your doctor will likely adjust their dosage or stop treatment with them.

Mood changes, including suicidal thoughts or behaviors. Epidiolex may cause mood changes, including depression and suicidal thoughts or behaviors. Before starting treatment, tell your doctor if you have a condition that affects your mood. They can tell you whether Epidiolex is a safe treatment option.

Allergic reaction. If you’ve had an allergic reaction to Epidiolex or any of its ingredients, including sesame seed oil, your doctor will likely not prescribe Epidiolex. Ask your doctor what other medications may be better options for you.

Pregnancy or breastfeeding. If you’re pregnant or breastfeeding your child, Epidiolex may not be safe for your pregnancy or child. Talk with your doctor before taking Epidiolex.

If you take Epidiolex during pregnancy, ask your doctor about enrolling in a pregnancy registry. The North American Antiepileptic Drug Pregnancy Registry looks at how antiepileptic drugs, such as Epidiolex, may affect pregnancy. To learn more, visit the registry’s website or call 888-233-2334.

Alcohol consumption. If you drink alcohol, Epidiolex may not be safe for you to take. Drinking alcohol while taking the drug could increase your risk of sleepiness and sedation and contribute to liver problems. If you have questions about drinking alcohol while taking Epidiolex, talk with your doctor or pharmacist. They may recommend that you do not drink alcohol while taking this drug.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.