If you’re looking at treatment options for certain types of leukemia or lymphoma, your doctor might suggest Calquence (acalabrutinib). Along with other questions you may have about the drug, you could be wondering about its side effects.

Calquence is a prescription medication that’s used to treat the following types of cancer in adults:

Calquence comes as a capsule that you swallow, and it’s available in one strength: 100 milligrams (mg). You’ll likely take one capsule every 12 hours.

Calquence is meant to be a long-term treatment.

For more information about Calquence, see this in-depth article on the drug.

Like other drugs that treat cancer, Calquence can cause mild or serious side effects. Keep reading to learn more.

Some people may experience mild or serious side effects during Calquence treatment. Examples of Calquence’s more commonly reported side effects include:

* To learn more about this side effect, see “Side effects explained” below.
† To learn more about this side effect, see “Digestive system issues” under” Side effects explained” below.

Calquence can cause mild side effects in some people. Examples of mild side effects that have been reported with Calquence include:

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

In most cases, these side effects should be temporary. 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. Don’t stop using Calquence unless your doctor recommends it.

Calquence may cause mild side effects other than the ones listed above. See the Calquence patient 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 Calquence, visit MedWatch.

Less commonly, serious side effects can happen with Calquence. Serious side effects that have been reported with Calquence include:

If you develop serious side effects while taking Calquence, 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 “Side effects explained” below.
† An allergic reaction is possible after using Calquence, but this side effect wasn’t reported in studies.

Learn more about some of the side effects that Calquence may cause.

Low blood cell levels

Low blood cell levels are common with Calquence, but this side effect is typically mild or easily managed. Less commonly, very low blood cell levels can lead to severe problems. What sort of problems you might develop depends on which of the following types of blood cells are affected:

Low red blood cell levels

Anemia is a common side effect of Calquence. It’s caused by a low level of red blood cells. Red blood cells carry oxygen throughout your body.

Without enough red blood cells, you may develop fatigue (lack of energy). Other possible symptoms of anemia include weakness, pale-looking skin, headache, and shortness of breath.

If you develop these symptoms, it’s important to tell your doctor. Don’t wait to see if they go away on their own.

Low white blood cell levels

Low white blood cell levels are a common side effect of Calquence and may include:

White blood cells are an important part of your immune system. Their job is to travel throughout your body, find any pathogens (germs), and fight them off. Without enough white blood cells, you could develop an infection more easily, such as a bacterial or viral infection.

An infection can be mild, such as the common cold, or severe, such as pneumonia. Symptoms of serious infection vary but may include fever, chills, body aches, or cough. If you develop symptoms of an infection while taking Calquence, tell your doctor right away.

Low platelet levels

Calquence can cause thrombocytopenia, defined as a low level of platelets (also called thrombocytes). This is a common side effect.

Platelets are a type of blood cell that helps to stop bleeding after an injury. When your skin gets injured or cut, platelets clot (clump together) to reduce the loss of blood. If you don’t have enough platelets in your body, your blood won’t be able to clot.

With thrombocytopenia, your blood may become “too thin,” increasing your risk for bleeding problems. Symptoms can range from mild to severe and include:

  • bruising easily
  • skin wounds that bleed for a long time
  • petechiae (a rash with small red, purple, or dark dots)
  • nosebleeds
  • bleeding gums, especially after brushing or flossing your teeth
  • heavy menstrual bleeding
  • coughing up blood
  • blood in your urine
  • bloody or dark-colored stool or vomit

Although not common, serious bleeding problems were reported in studies of Calquence. In rare cases, hemorrhages (very heavy bleeding) and brain bleeding have been fatal. If you’re taking a blood thinner with Calquence, you may have a higher risk for serious bleeding problems.

Before starting Calquence treatment, tell your doctor about all of the medications that you take. If you’re taking a blood thinner, they’ll likely monitor you more carefully while you’re taking Calquence.

What might help

Low blood cell levels are common with Calquence treatment. This side effect also commonly occurs with many other types of cancer treatment.

As a result, your doctor will suggest a plan to manage your blood cell levels during Calquence treatment. This will likely include regularly checking your blood with a simple blood test called a complete blood count. Your doctor may also suggest certain medications such as Neupogen (filgrastim) or an iron supplement to help prevent or treat low blood cell levels.

If your symptoms become severe, your doctor may have you stop Calquence. They’ll let you know when it’s safe for you to start taking the drug again. If it’s not safe to resume Calquence treatment, they may suggest a different treatment option.

If you have questions or concerns about low blood cell levels with Calquence, talk with your doctor.

Digestive system issues

Digestive side effects can happen in some people taking Calquence. In studies of the drug, diarrhea was one of the most common side effects, and it can be severe.

For many, diarrhea can develop within 2 months after starting treatment, with the side effect easing after a week.

Other digestive side effects can include:

What might help

For most people, the digestive side effects of Calquence are temporary. Eating small, frequent meals that include bland foods may help to ease these side effects.

Diarrhea or vomiting can lead to dehydration. If you develop these digestive side effects, it’s important to drink plenty of fluids.

If you have diarrhea or vomiting that becomes severe or doesn’t go away, tell your doctor. They may recommend medical treatment such as giving you fluids intravenously (through a vein). Or they may suggest an antidiarrheal medication, such as loperamide (Imodium), or an anti-nausea drug, such as ondansetron (Zofran).

If you have questions about digestive system issues during Calquence treatment, talk with your doctor.

Headache

Headache was one of the most common side effects reported in studies of Calquence. But it’s usually a temporary side effect.

According to the manufacturer of Calquence, headache from taking the drug develops within 5 days of starting treatment for many people. This side effect can last around 2 weeks.

Headache from Calquence is usually mild but can be severe for some people.

What might help

Acetaminophen (Tylenol), an over-the-counter (OTC) pain reliever, may help to relieve a headache from taking Calquence.

Here are a few other tips to try that may ease this side effect:

  • A headache can occur or get worse if you become dehydrated. Try to drink plenty of water and other fluids throughout the day.
  • Light to moderate exercise can help release endorphins (brain chemicals), which may ease pain. Consider going for a walk or doing another type of exercise that you enjoy.
  • Caffeine can help to relieve headache pain in some people. If it’s safe for you to consume caffeine, consider having a cup of coffee or tea.

If your headache becomes severe or doesn’t go away, talk with your doctor. They may suggest other ways to relieve a headache caused by Calquence.

Muscle pain

Muscle pain is a possible side effect of Calquence. In studies, the following types of muscle-related pain were commonly reported in people taking the drug:

  • muscle pain or discomfort
  • back pain
  • neck pain
  • pain in the arms, hands, legs, or feet

For most people, muscle pain is a mild side effect of Calquence.

What might help

Some of the tips for relieving a headache given above may also be helpful for muscle pain: taking acetaminophen (Tylenol), staying hydrated, and exercising.

Heat can also help relax tense muscles and provide some relief. Consider taking a hot shower or bath or using a heating pad. A daily stretching routine can be useful to help prevent muscle injuries.

An OTC treatment option for easing muscle pain is topical menthol. (“Topical” means you apply it to your skin.) Examples include Bengay, Biofreeze, and Mineral Ice. If you have any questions about using topical menthol, ask your doctor or pharmacist.

If your muscle pain is severe or bothersome, talk with your doctor. They may suggest other ways to relieve this side effect.

Rash

Rash is a possible side effect of Calquence treatment. In studies, rash was a mild side effect for most people.

Although rare, severe rash is possible with Calquence. In a study of Calquence to treat chronic lymphocytic leukemia, severe rash occurred more frequently in people taking Calquence with another drug compared with those taking Calquence alone.

What might help

Rash from Calquence is typically mild and temporary. You might not need any treatment for it.

If you develop a rash after starting Calquence, talk with your doctor. They may be able to suggest ways to ease this side effect.

If you have certain symptoms with a rash, you could be having an allergic reaction. For more information, see the next section.

Allergic reaction

Like most drugs, Calquence can cause an allergic reaction in some people. But this side effect wasn’t reported in studies.

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 your symptoms, they may suggest an OTC 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 Calquence, 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 Calquence, they may have you switch to a different treatment.

Keeping track of side effects

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

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

How do Calquence’s side effects compare with those of Imbruvica?

Calquence and Imbruvica both treat some of the same types of cancer. These drugs work similarly, so they can cause similar side effects. But some different side effects, including serious ones, are also possible.

Imbruvica’s serious side effects include increased blood pressure and tumor lysis syndrome. (With tumor lysis syndrome, cancer cells release harmful chemicals into your blood as they’re broken down.)

Calquence isn’t known to cause either of these serious side effects, but it can cause other serious side effects. For more information, see “What are the serious side effects of Calquence?” above.

Your doctor can help guide you on which treatment option is better for your condition.

Does Calquence cause any long-term side effects?

Yes, it’s possible to have long-term side effects from taking Calquence.

The most common side effects of Calquence are usually temporary. Less commonly, Calquence can cause serious side effects that may have long-term effects. Examples include heart problems and new types of cancer.

Some people taking Calquence develop long-term heart rhythm problems. These include atrial flutter and atrial fibrillation.

If you already have a heart problem or high blood pressure, you may have a higher risk for heart rhythm problems. Before starting Calquence, be sure to talk with your doctor about your health history.

Some people taking Calquence develop new types of tumors or skin cancer. You can help to reduce your risk for skin cancer by using sun protection.

Can Calquence cause fatigue?

Yes, it can. Fatigue (lack of energy) is a symptom of anemia, which is a common side effect of Calquence. It’s caused by a low level of red blood cells. Red blood cells carry oxygen throughout your body.

Without enough red blood cells, you may develop fatigue. Other symptoms of anemia include weakness, pale-looking skin, headache, and shortness of breath.

If you develop these symptoms with Calquence, it’s important to tell your doctor. They’ll likely test your blood to check for a low red blood cell level or other signs of anemia. Your doctor may recommend treatment to correct your anemia, such as taking an iron supplement.

I’m bruising a lot more easily. Is this a side effect of Calquence?

Yes, it is. Skin bruising occurs when tiny blood vessels called capillaries become damaged and bleed. The blood gets trapped below your skin’s surface, causing a darkened or discolored area. As the bruise heals, the discolored area should start to go away.

Taking a drug such as Calquence can cause you to bruise more easily. This is because Calquence can result in thrombocytopenia (low levels of platelets). Platelets are a type of blood cell that helps to stop bleeding after an injury. Without enough platelets, you’re more likely to have bleeding or bruising, even after minor injuries that you don’t remember.

Bruising a lot can be a sign that your platelets are lower than usual. Other symptoms include bleeding gums, nosebleeds, or wounds that take a long time to stop bleeding.

If you notice these symptoms, be sure to tell your doctor. They’ll monitor your platelet levels with blood tests regularly during Calquence treatment.

Calquence 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 Calquence. The list below includes factors to consider.

Heart problems. Calquence can cause serious heart rhythm problems such as atrial fibrillation. If you already have a heart condition, the drug may further increase your risk for heart rhythm problems. It could also make your condition worse. Be sure to talk with your doctor about any heart problem you have. If you start taking Calquence, they’ll determine the safest treatment option for your heart condition and monitor you carefully.

Liver problems, such as hepatitis B. If you’ve had hepatitis B in the past, Calquence may cause it to come back. (Hepatitis B is a liver infection caused by the hepatitis B virus.) Also, if you have liver problems, or have had them, your doctor may need to adjust your dosage of Calquence.

Bleeding problems. Calquence can increase your risk for bleeding. If you already have a bleeding problem, the drug could worsen your condition. If you have a medical condition that affects your blood, or had such a condition in the past, talk with your doctor. They can tell you whether it’s safe for you to try Calquence treatment.

Infection. Calquence may increase your risk for developing an infection. Before you start taking Calquence, tell your doctor about any infection you have, even if it’s minor. It’s important that any infection you have is treated before you take the drug.

Upcoming surgery. Calquence can increase your risk for bleeding. Because of this risk, you should tell your doctor about any surgery that you’re scheduled to have. They’ll likely have you stop taking Calquence temporarily. Ask your surgeon or doctor for detailed instructions on stopping and restarting your medications.

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

Alcohol use and Calquence

There’s no known interaction between alcohol and Calquence.

But if you’re taking Calquence with Gazyva (obinutuzumab) for chronic lymphocytic leukemia or small lymphocytic lymphoma, you should avoid alcohol.

If you drink alcohol and you’re not taking Gazyva, talk with your doctor about how much alcohol is safe for you to consume during Calquence treatment.

Pregnancy and breastfeeding while taking Calquence

You shouldn’t take Calquence if you’re pregnant or planning to become pregnant. The drug may cause harm to a developing fetus or pregnant person.

You shouldn’t breastfeed a child while taking Calquence and for 2 weeks after your last dose.

If you’re planning to become pregnant or breastfeed, talk with your doctor. They may suggest other treatment options or offer other medical advice, depending on your condition.

Calquence can be an effective treatment option for certain types of leukemia and lymphoma. But for some people, the drug can cause mild or serious side effects.

When you’re considering a new treatment, it’s important to talk with your doctor about the possible side effects. They’ll help you decide whether the potential benefits of Calquence for your condition outweigh its risks.

Here are some questions to consider asking your doctor:

  • Do my other medications increase my risk for side effects with Calquence?
  • How often do I need to get blood tests to check for Calquence’s side effects?
  • What can I do to help prevent serious side effects of Calquence?

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.