If you have a certain kind of breast cancer, your doctor might suggest Kisqali (ribociclib) as a treatment option for you.

Kisqali is a prescription medication used in adults to treat breast cancer that is HER2-negative, hormone receptor-positive, and advanced or metastatic.

This drug comes as a 200 milligram (mg) tablet that you take by mouth once each day. The typical dosage is 600 mg daily for 21 days, followed by 7 days of not taking the drug.

Kisqali is meant to be used as a long-term treatment for breast cancer.

For more information about Kisqali, including details about its uses, see this in-depth article or the drug’s prescribing information.

Like other drugs, Kisqali can cause mild or serious side effects (also referred to as adverse effects). Keep reading to learn more.

Some people may experience mild or serious side effects during their Kisqali treatment. Kisqali’s common side effects are mild in most people who have them.

Examples of Kisqali’s commonly reported side effects include:

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

It’s possible you’ll have mild side effects from taking Kisqali, and some are more common than others. Keep in mind that side effects from medications such as Kisqali can vary from person to person.

Examples of mild side effects that have been reported with Kisqali include:

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

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or that bother you, talk with your doctor or pharmacist. And do not stop using Kisqali unless your doctor recommends it.

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

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

Serious side effects that have been reported with Kisqali include:

If you develop serious side effects while taking Kisqali, 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.

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

It’s normal to have questions about medications your doctor may have prescribed. Below are answers to some frequently asked questions about Kisqali’s side effects.

Will taking Kisqali with Femara increase my risk of certain side effects?

It’s possible that taking Kisqali with Femara (letrozole) may increase the risk of certain side effects.

Kisqali is used with other drugs to treat advanced breast cancer. Specifically, Kisqali is used with either Faslodex (fulvestrant) or a type of drug called an aromatase inhibitor, such as Femara.

In studies of Kisqali, there were some slight differences in side effects, depending on which medication people took with Kisqali.

For example, people who took Kisqali with Femara reported trouble sleeping as a side effect. But this wasn’t reported by people who took Kisqali with Faslodex. Those who took Kisqali with Faslodex reported dizziness as a side effect, but people taking Kisqali with Femara didn’t.

So your risk of side effects can vary slightly depending on other medications you take with Kisqali. But reported side effects were mainly the same, regardless of which drug was used with Kisqali.

Can Kisqali cause weight gain?

It’s unlikely. In studies, weight gain wasn’t reported as a side effect by people taking Kisqali.

But people who took Kisqali with the drug Femara did report edema (fluid retention and swelling). While this side effect can cause some weight gain, it usually goes away with treatment for the swelling. If you have edema from taking Kisqali, your doctor can recommend treatment options for it.

If you have questions or concerns about your weight and your cancer treatment regimen, talk with your doctor.

Are there lab tests to check for side effects from taking Kisqali?

For some of the side effects Kisqali may cause, your doctor can order certain lab tests. As an example, your doctor will likely order tests to check your liver health regularly while you’re taking this drug. This helps monitor for liver damage, a possible serious side effect of Kisqali.

There are other lab tests your doctor will likely have you get while you’re taking Kisqali. Talk with your doctor to find out more about the tests they’ll order for you during your Kisqali treatment.

If I have side effects with Kisqali, will I need to stop taking it?

It depends. Whether you keep taking Kisqali after having side effects is a decision you and your doctor will make together.

Some of Kisqali’s side effects are severe enough that you may need to stop taking the drug if you experience any of them.

For example, if you have a serious skin reaction from taking Kisqali, your doctor will likely have you stop treatment. This is because skin reactions caused by Kisqali can be life threatening in rare cases. And these reactions can occur again if you keep taking Kisqali. (For more information on skin reactions Kisqali may cause, see the “Side effects explained” section below.)

But you may be able to keep taking Kisqali if you develop side effects that aren’t bothersome to you. For example, it’s common to have mild nausea while taking Kisqali. But most people who have this side effect are able to keep taking the drug.

Talk with your doctor if you think you’re having side effects from taking Kisqali. They can discuss the options available for you. These may include waiting to see if the side effect goes away or lowering your dose of Kisqali. Or they may suggest switching to another treatment for your cancer.

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

Hair loss

Hair loss or thinning is a possible side effect from taking Kisqali. In studies, this was among the more common side effects. Other medications used together with Kisqali, such as Femara (letrozole) and Faslodex (fulvestrant), can also cause this side effect.

Keep in mind that hair loss is also a side effect caused by many other cancer treatments.

What might help

Talk with your doctor if you have hair loss or thinning while taking Kisqali. To treat it, they may recommend a medication such as Rogaine (minoxidil). Although Rogaine is available over the counter, you should talk with your doctor before using it. They’ll need to check whether it interacts with medications you’re taking for your cancer treatment.

Besides medications, there are other things to try that may help you manage hair loss caused by Kisqali. These include:

For tips that may help lessen this side effect, see this article.


You may experience fatigue (low energy) from treatment with Kisqali. This was one of the most common side effects in studies of people who took Kisqali together with Femara. But it wasn’t reported in people who took Kisqali with Faslodex (fulvestrant).

Trouble sleeping was also a side effect reported in people who took Kisqali with letrozole, and this can cause or worsen fatigue.

Other side effects that have been reported with Kisqali treatment, regardless of what other drugs were taken with it, can also cause or worsen fatigue. These include:

Keep in mind that cancer itself can cause fatigue.

What might help

Talk with your doctor if you’re experiencing fatigue while taking Kisqali. They can work with you to find the best approach to treating this side effect. You can check out this article for ways to manage cancer-related fatigue. And the American Cancer Society website also features tips that may help ease this side effect.

Long QT syndrome

Although uncommon, a cardiac side effect called long QT syndrome can happen with Kisqali treatment. (“Cardiac” means it affects your heart.)

The QT interval is part of your heart’s natural rhythm. In studies, Kisqali caused the QT interval to lengthen. This is known as long QT syndrome. In some people, long QT syndrome doesn’t cause problems or any symptoms. But this condition can cause an abnormal heartbeat that is life threatening in rare cases.

Some people are born with long QT syndrome. But it can also be caused by taking certain medications, including Kisqali.

Certain people are at higher risk of long QT syndrome. Having certain medical conditions or taking certain medications can increase your risk of long QT syndrome during Kisqali treatment. In this case, a doctor may recommend a medication other than Kisqali for your breast cancer.

Long QT syndrome often doesn’t cause symptoms. But some people may notice symptoms, such as:

What might help

Before you start taking Kisqali, your doctor will check your heart rhythm with an electrocardiogram (EKG). You’ll continue having EKGs during your treatment. This can help your doctor detect long QT syndrome before it causes symptoms or becomes severe.

Your doctor will also check your electrolyte levels before you start treatment, and they’ll continue monitoring them during treatment. This is because certain electrolytes, including potassium and magnesium, play an important role in maintaining a healthy heart rhythm.

If you think you’re having symptoms of long QT syndrome, contact your doctor right away. They’ll likely recommend that you have an EKG and possibly other tests.

If you develop long QT syndrome from taking Kisqali, your doctor may temporarily pause your treatment or lower your dose of the drug. Or they may recommend that you permanently stop taking it.


Neutropenia is the most common side effect reported in studies of people taking Kisqali. With neutropenia, you have low blood levels of neutrophils. These are a type of white blood cell that helps your body fight off infections.

This condition can be mild or severe. It’s common to have severe neutropenia while taking Kisqali, regardless of which other medications you take with it. But even when it’s severe, most people are able to keep taking Kisqali.

Neutropenia typically doesn’t cause symptoms. But having low neutrophil levels can make you more likely to get an infection. And it increases your risk of serious infections. So you may notice symptoms of infection, such as chills or fever.

What might help

Before you start taking Kisqali, your doctor will check your neutrophil levels with a blood test. They’ll continue monitoring these levels during your treatment.

If you have neutropenia as a side effect from Kisqali, your doctor may temporarily pause your treatment or lower your dose of the drug. Or they may recommend that you permanently stop taking it.

When Kisqali treatment is paused, neutrophil levels usually return to normal within about 12 days.

Severe skin reactions

While rare, Kisqali can cause severe skin reactions. In extreme cases, these reactions can be life threatening. This side effect wasn’t reported in studies of Kisqali, but it has been reported since the drug was approved.

Severe skin reactions that Kisqali can cause include:

Symptoms of these reactions can include:

  • blisters on your eyes, lips, mouth, or skin
  • fever
  • flu-like symptoms
  • rash that continues to get worse or severe rash
  • redness or deepening of skin color
  • skin burning or pain
  • skin peeling

What might help

If you think you’re having a severe skin reaction to Kisqali, contact your doctor immediately. These reactions can be serious and may require treatment in a hospital. If your symptoms feel life threatening, seek emergency medical attention right away.

If you have a severe skin reaction from Kisqali, your doctor will pause your Kisqali treatment. Once the reaction has been treated and goes away, your doctor may have you resume taking the same dose or a lower dose of Kisqali. Or they may recommend that you permanently stop taking the drug.

Allergic reaction

Like most drugs, Kisqali 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. To manage symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine). Or they may recommend a product you apply to your skin, such as hydrocortisone cream.

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

Keeping track of side effects

During your Kisqali 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 Kisqali affects you. And your doctor can use this information to adjust your treatment plan if needed.

Kisqali may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take Kisqali. The list below includes factors to consider.

Heart problems. Kisqali may cause heart problems. People with existing heart problems, such as heart failure, slow or irregular heartbeat, or long QT syndrome, may have a higher risk of this side effect. This also applies if you’ve ever had a heart attack. Tell your doctor about any heart problems you have. This will help them determine if treatment with Kisqali is safe for you.

Electrolyte problems. Having problems with blood levels of specific electrolytes can increase your risk of certain Kisqali side effects, including those that are heart-related. If you have problems with your potassium, magnesium, calcium, or phosphorus levels, tell your doctor. They can determine if Kisqali is safe for you to take.

Infection. Treatment with Kisqali makes it harder for your body to fight off infection. If you have an active infection, tell your doctor before you begin taking Kisqali. They’ll likely want to treat the infection before prescribing this drug.

Liver problems. Treatment with Kisqali can cause liver problems, including liver damage, as a side effect. If you already have a liver problem, such as hepatitis, you have a higher risk of this side effect if you take Kisqali. Tell your doctor about any liver problems you have. This can help them determine if treatment with Kisqali is safe for you.

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

Alcohol use and Kisqali

There’s no known interaction between consuming alcohol and taking Kisqali. But drinking alcohol could worsen certain side effects of Kisqali, such as fatigue (low energy), nausea, diarrhea, or headache. During Kisqali treatment, drinking alcohol could also increase your risk of having these side effects.

If you want to drink alcohol while taking Kisqali, ask your doctor how much is safe for you to consume.

Pregnancy and breastfeeding while taking Kisqali

Kisqali is not safe to take during pregnancy or while breastfeeding. Based on how the drug works, it could cause fetal harm if taken during pregnancy.

If you’re able to become pregnant, your doctor will give you a pregnancy test before you start taking Kisqali. They’ll also recommend you use birth control while taking Kisqali and for 3 weeks after your last dose.

It’s not known if Kisqali passes into breast milk. But if it does, it’s thought the drug could cause serious side effects in a breastfed child. Your doctor will likely recommend that you do not breastfeed while taking Kisqali and for 3 weeks after your last dose.

If you’re pregnant, breastfeeding, or thinking about becoming pregnant or breastfeeding, talk with your doctor before you start Kisqali treatment.

Some side effects are common with Kisqali. Most people who take the drug will have side effects, but these are usually mild. Mild side effects may go away with time, and some can be treated.

While Kisqali can cause serious side effects, these are rare.

To find out more about Kisqali, including its side effects, ask your doctor for information about the drug. Here are a few questions to get you started:

  • Do I have a higher risk of side effects than other people taking Kisqali?
  • Can Kisqali cause any long-term side effects?
  • How can I treat some of the side effects Kisqali can cause?
  • If I have side effects that are bothersome, can my dose of Kisqali be reduced?

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I have chronic obstructive pulmonary disease (COPD). Is it safe for me to take Kisqali?



If you have or have had any lung conditions, including COPD, you should tell your doctor. It’s possible that they may prescribe Kisqali even if you have COPD.

Kisqali can lead to severe or even life threatening swelling in your lungs. With COPD, you’ll likely already have swelling in your lungs. If you begin experiencing any new or worsening lung symptoms while taking Kisqali, contact your doctor right away. These symptoms may include trouble breathing, shortness of breath, cough, or chest pain.

Melissa Badowski, PharmD, MPH, FCCPAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Disclaimer: Healinggeeks 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.