If you have a certain form of cancer, your doctor might suggest Lenvima (lenvatinib) as a treatment option for you. Along with other questions you may have about the drug, you could be wondering about its side effects.

Lenvima is a prescription medication that’s used in adults to treat:

Whether Lenvima is a good treatment option for your cancer depends on additional factors. And depending on the type of cancer you have, you may need to take certain other cancer drugs with Lenvima.

Lenvima is a capsule that you take by mouth. It’s a targeted therapy, which means it blocks specific proteins that help cancer grow.

For more information about Lenvima, including details about its uses, see this in-depth article on the drug.

Like other drugs, Lenvima can cause mild or serious side effects. Keep reading to learn more.

Listed below are some of the more commonly reported side effects of Lenvima. Keep in mind that these aren’t all the common side effects of this drug. Also, possible side effects may vary based on the type of cancer you’re using Lenvima to treat.

Commonly reported side effects of Lenvima for all uses include:

Here are some of the other commonly reported side effects for each of Lenvima’s uses.

For differentiated thyroid cancer:

  • headache
  • vomiting
  • protein in your urine*
  • hand-foot syndrome* (pain, swelling, and redness on your palms or the soles of your feet)

For renal cell carcinoma:†

For hepatocellular carcinoma:

For endometrial carcinoma:‡

* To learn more about this side effect, see “Side effects explained” below.
† These side effects were reported in a study of Lenvima used with everolimus (Afinitor, Zortress) for renal cell carcinoma.
‡ These side effects were reported in a study of Lenvima used with pembrolizumab (Keytruda) for endometrial carcinoma.

Listed below are some of the mild side effects that Lenvima may cause. Depending on the type of cancer you’re using Lenvima to treat, side effects may vary.

Examples of mild side effects that were reported for all uses of Lenvima include:

* To learn more about this side effect, see “Side effects explained” below.

These mild side effects may get better over time, and some may be easily managed. Others may become serious, such as diarrhea, or can be symptoms of serious side effects, such as belly pain.

If you have symptoms that become severe, don’t go away, or bother you, talk with your doctor or pharmacist right away. But do not stop taking Lenvima unless your doctor recommends it.

Lenvima may cause mild side effects other than the ones listed above. See the Lenvima patient information for details.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Lenvima, visit MedWatch.

Lenvima may cause serious side effects. Most of Lenvima’s serious side effects aren’t common. Some people may be at higher risk of certain serious side effects. To learn about your risks, talk with your doctor.

Serious side effects that have been reported with Lenvima include:

* To learn more about this side effect, see “Side effects explained” below.

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

Get answers to some frequently asked questions about Lenvima’s side effects.

Do side effects of Lenvima vary depending on the capsule strength (4 mg or 10 mg)?

Your risk of side effects from Lenvima doesn’t fully depend on the actual capsule strengths that it comes in. But in general, you may have more severe symptoms from certain side effects if you take higher dosages of Lenvima. Higher dosages may also increase your risk for serious side effects.

For example, the starting dosage of Lenvima for treating differentiated thyroid cancer is 24 milligrams (mg) once daily. This means you’ll likely take two 10-mg capsules and one 4-mg capsule once daily.

If you have a high level of protein in your urine while taking this dosage, your doctor will pause your treatment. When your urine protein level is back to normal, you’ll restart Lenvima at 20 mg once daily. If the problem happens again, after a pause you’ll restart Lenvima at 14 mg once daily.

The usual dosages of Lenvima vary by which cancer it’s being used to treat. They range from 8 mg to 24 mg once daily. But they may be lower if you have severe kidney or liver problems.

If you have concerns about side effects and Lenvima dosage, ask your doctor about:

  • the usual dosage for treating your condition
  • risks of serious side effects at this dosage
  • steps to manage these problems, such as pausing your treatment, lowering your dosage, or stopping treatment with this drug

Note: If you currently take Lenvima, do not change or stop your treatment without talking with your doctor first.

Does Lenvima cause the type of blood clots that can travel to your lungs?

No, blood clots in the lungs haven’t been reported with Lenvima.

Blood clots in your lungs are called pulmonary embolisms. And these types of blood clots form in your veins (blood vessels that carry blood toward your heart).

Although uncommon, Lenvima may cause blood clots to form in your arteries (blood vessels that carry blood away from your heart). These types of clots may lead to a heart attack or stroke.

If you’re concerned about blood clots with Lenvima, talk with your doctor.

Is it OK to use Lenvima if you’ve had osteonecrosis of the jaw?

Yes, generally speaking. Your doctor may still prescribe the drug if you’ve had osteonecrosis of the jaw (ONJ) that’s healed. ONJ refers to damaged or dead jawbone tissue.

ONJ is a rare but serious side effect of Lenvima that can lead to bone damage and tooth loss. Your risk for ONJ may increase while taking Lenvima if you also:

Before taking Lenvima, your doctor will check your oral health. While taking this drug, you can help prevent ONJ by taking good care of your mouth and teeth.

Also, you should see your dentist on a regular basis and try to avoid invasive dental work. If you need such a procedure, talk with your doctor about how to lower your ONJ risk. For example, they may have you stop taking Lenvima for at least 1 week before your procedure.

For questions about ONJ and Lenvima, talk with your doctor and dentist. Also, do not stop or change any of your medications without your doctor’s instructions.

Learn more about some of the side effects Lenvima may cause.

Hand-foot syndrome

While taking Lenvima, you may develop hand-foot syndrome. This side effect was commonly reported in studies of Lenvima for treating:

* This side effect was reported in a study of Lenvima used with pembrolizumab (Keytruda) for endometrial carcinoma.

Hand-foot syndrome, also called palmar-plantar erythrodysesthesia, is a side effect of certain cancer drugs. Typically, symptoms may include:

  • pain
  • burning or tingling
  • swelling
  • redness on the palms of your hands or soles of your feet

But this syndrome can become severe and cause serious symptoms, such as:

  • blisters
  • skin cracking or peeling
  • severe pain
  • trouble using your hands or walking

What might help

Call your doctor right away if you notice any symptoms of hand-foot syndrome or skin changes on your palms or soles. If your doctor confirms you’re having this side effect, they’ll suggest treatments based on your symptoms.

For example, they may suggest nondrug treatments to help ease mild symptoms or keep them from getting worse, such as:

  • taking cool baths or showers
  • applying cool compresses or cold packs
  • avoiding hot water and highly heated environments, like saunas
  • using mild soap for your hands and laundry
  • gently applying mild lotion to moisten your skin

If needed, your doctor may prescribe a topical steroid drug to relieve swelling or redness. (“Topical” means you apply it to your skin.) An example is halobetasol (Ultravate). Or they may suggest a topical drug for tingling or pain, such as lidocaine cream. Your doctor may recommend other medications, too.

To learn more about hand-foot syndrome with Lenvima, talk with your doctor or pharmacist.

Mouth swelling or soreness

While taking Lenvima, you may develop swelling or soreness in your mouth. These were common side effects in studies of Lenvima for treating:

* These side effects were reported in a study of Lenvima used with everolimus (Afinitor, Zortress) for renal cell carcinoma.
† These side effects were reported in a study of Lenvima used with pembrolizumab (Keytruda) for endometrial carcinoma.

Mouth swelling or soreness is called stomatitis. With stomatitis, you may have symptoms that make it hard to eat, talk, or swallow, such as:

What might help

If you notice any mouth-related symptoms with Lenvima, call your doctor right away. They may suggest a mouth rinse to help ease discomfort or pain, such as viscous lidocaine. Or they may prescribe a mouth rinse that your pharmacist prepares to help sooth irritation and heal any ulcers.

To relieve mild mouth soreness and prevent new or worsening mouth symptoms, try these tips:

  • Clean your mouth and teeth, avoiding alcohol-based mouthwash, sharp toothpicks, and brushing or flossing hard.
  • Keep your mouth moist by sipping water, sucking on sugar-free hard candies, or using saliva substitutes.
  • Avoid smoking, vaping, and drinking alcohol.
  • Don’t eat spicy, crunchy, or acidic foods.

For questions about mouth swelling or soreness with Lenvima, talk with your doctor or dentist.

Decreased appetite or weight loss

While taking Lenvima, you may have decreased appetite or weight loss. These were common side effects reported for all uses of Lenvima.

When you feel less hungry, you may not get enough energy or nutrients from your diet. This can lead to weight loss. But decreased appetite or weight loss can also lead to other health problems, such as low energy or weakness.

What might help

Typically, good nutrition and maintaining a healthy weight are key parts of any cancer treatment plan. You can take steps at home to help improve your appetite and limit weight loss, such as:

  • eating small, high-calorie snacks or small meals throughout your day
  • creating an eating plan with a dietitian or nutritionist
  • asking your doctor about calorie-boosting shakes, such as Ensure
  • managing other side effects that affect decreased appetite or weight loss, such as nausea or vomiting

If you’re losing too much weight, your doctor may prescribe medication to help boost your appetite and encourage weight gain. In serious cases, your doctor may suggest short-term tube feedings. (These feedings deliver liquid nutrients to your stomach or gut through a tube placed in your nose.) They may also recommend other treatments for severe weight loss.

Before starting Lenvima, talk with your doctor about the best ways to manage appetite and weight loss.

Allergic reaction

Like most drugs, Lenvima can cause an allergic reaction in some people.

Symptoms can be mild or serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • 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 might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine), or a product you apply to your skin, such as hydrocortisone cream, to manage your symptoms.

If your doctor confirms you had a mild allergic reaction to Lenvima, they’ll decide if you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you had a serious allergic reaction to Lenvima, they may have you switch to a different treatment.

Keeping track of side effects

During your Lenvima treatment, consider keeping notes on any side effects you’re having. Then, you can share this information with your doctor. This is especially helpful to do when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of drug you were taking when you had the side effect
  • how soon after starting that dose you had the side effect
  • what your symptoms were from the side effect
  • how it affected your daily activities
  • what other medications you were also taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help your doctor learn more about how Lenvima affects you. And your doctor can use this information to adjust your treatment plan if needed.

Lenvima may not be right for you if you have certain medical conditions or other factors that affect your health. Before starting Lenvima, discuss your full health history with your doctor. The list below includes factors to consider.

Poor dental health. Taking Lenvima may increase your risk for osteonecrosis of the jaw (damaged or dead jawbone tissue). Poor dental health or severe tooth or gum disease may increase your risk for this serious side effect. Before starting Lenvima, tell your doctor about your oral health. (See “Side effects explained” for more information.)

Certain heart problems or abnormal electrolytes. Lenvima can cause long QT syndrome, which causes a dangerous heart arrythmia (abnormal heartbeat). Having abnormal blood electrolyte levels, heart failure, or a slow heartbeat can increase this risk. So can taking certain antiarrhythmic drugs.

Before you start taking Lenvima, tell your doctor about all medications you take and let them know about any heart problems you may have. They’ll test your electrolytes and check your heartbeat. During treatment, they’ll monitor your heartbeat and, if needed, pause your treatment, lower your dosage, or have you stop taking the drug.

High blood pressure. Lenvima can cause new or worsening high blood pressure. Tell your doctor if you have high blood pressure before taking Lenvima, even if you take medication to manage it. They’ll make sure your high blood pressure is managed before you start taking Lenvima.

Your doctor will check your blood pressure before and during Lenvima treatment. If your numbers are high, they’ll lower your dosage or pause your treatment until your blood pressure is normal. If you have severe or unmanageable high blood pressure during Lenvima treatment, they may have you stop taking the drug.

History of certain blood clots. Lenvima increases your risk for health problems caused by blood clots that form in your arteries. (These are blood vessels that carry blood away from your heart.) It’s unknown if Lenvima is safe to use within 6 months of a problem caused by these blood clots, such as a heart attack. Tell your doctor about any recent blood clots or health problems you may have had, such as heart attack or stroke. They may recommend a treatment other than Lenvima for your condition.

Moderate or severe liver damage. Lenvima can damage your liver. Tell your doctor about your liver health. If you have moderate to severe liver damage, you may need a lower dosage of Lenvima. Also, your doctor may monitor your liver closely to check for new or worsening problems. If needed, they may pause your treatment, lower your dosage, or have you stop taking the drug.

Severe kidney disease. Lenvima can cause kidney problems, such as protein in your urine, decreased kidney function, or kidney failure. Tell your doctor about your kidney health. If you have severe kidney disease, you may need a lower dosage of Lenvima. Your doctor will check how your kidneys are working from time to time. If needed, they may pause your treatment, lower your dosage, or have you stop taking the drug.

Recent major surgery. Lenvima may make it harder for wounds to heal. You should not begin taking Lenvima for at least 2 weeks after a major surgery, and only if any wounds have healed. Before you start Lenvima treatment, tell your doctor about any recent surgeries. During treatment, you should stop Lenvima at least 1 week before any planned surgeries. But do not stop your treatment without talking with your doctor first.

Allergic reaction. If you’ve had an allergic reaction to Lenvima or any of its ingredients, you should not take Lenvima. Ask your doctor what other medications are better options for you.

Alcohol use and Lenvima

Drinking alcohol doesn’t affect how Lenvima works in your body.

However, drinking alcohol while using Lenvima may worsen certain side effects, such as nausea or vomiting, diarrhea, headache, and fatigue (lack of energy).

Also, drinking alcohol can cause dehydration, which can increase your risk for kidney problems with Lenvima.

Both Lenvima and excessive alcohol consumption can damage your liver. While taking the drug, consider avoiding alcohol to lower your risk for serious liver problems.

If you’re concerned about alcohol use with Lenvima, talk with your doctor.

Pregnancy and breastfeeding while taking Lenvima

The overall safety of Lenvima during pregnancy is unknown. But it’s not recommended you take Lenvima while pregnant. If you can become pregnant, you should use birth control while taking the drug and for at least 30 days after you stop taking it. These warnings are based on how the drug works and other factors.

Also, you should not breastfeed while taking Lenvima and for at least 1 week after you stop taking the drug. It’s unknown if Lenvima passes into breast milk. But if it does, Lenvima could harm a breastfed child.

Talk with your doctor if you have questions about:

  • the safety of Lenvima during pregnancy
  • birth control options during Lenvima treatment
  • the best way to feed your child while taking Lenvima

Lenvima may be a treatment option for your type of cancer. While treating your cancer, it may also cause side effects. However, most of the drug’s serious side effects are rare. And its common side effects are mostly mild or manageable.

If you’re unsure about Lenvima’s side effects or how to manage them, talk with your doctor or pharmacist. Get the answers you need to feel confident about your cancer treatment plan. Here are some questions to get you started:

  • If I get high blood pressure with Lenvima, will it go back to normal after my treatment ends?
  • Will any common side effects of Lenvima get better in time?
  • I have mild but frequent diarrhea with Lenvima. What can I do to manage this side effect?
  • My partner is taking Lenvima and we want to plan a pregnancy. Does this drug affect male* fertility?

* Sex and gender exist on spectrums. Use of the term “male” in this article refers to sex assigned at birth.

Disclaimer: Healthline 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.