Leukeran (chlorambucil) is a prescription brand-name medication. It’s approved by the Food and Drug Administration (FDA) for palliative treatment of the following types of cancer in adults:

Palliative treatment is supportive care that helps to improve quality of life for people with long-term or serious conditions. For this purpose, Leukeran may be taken for up to a year.

Here are some fast facts about Leukeran:

As with other drugs, Leukeran can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of Leukeran, including details about its uses, see this article.

Leukeran 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 Leukeran in clinical trials:

* For more information about this side effect, see “Side effect specifics” below.

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

Mild side effects that have been reported with Leukeran 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 side effects of the medication. If you develop a side effect while taking Leukeran and want to tell the FDA about it, visit MedWatch.

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

If you develop serious side effects while taking Leukeran, 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:

* For more information about this side effect, see “Side effect specifics” below.
† Leukeran has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA).
‡ For more information about this warning, see the “Leukeran precautions” section below.

Leukeran is not approved for use in children, and the drug’s safety and effectiveness in children haven’t been studied. However, as with other cancer treatments, Leukeran is sometimes prescribed off-label for use in children. Off-label refers to prescribing a drug for a purpose other than what it’s been approved for by the FDA.

In addition to the other side effects described elsewhere in this article and Leukeran’s prescribing information, seizures are a possible side effect in children taking Leukeran. The risk of seizures may be higher in children who:

Be sure to talk with your child’s doctor about their risk factors for seizures and other side effects.

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

If I’ve had radiation therapy in the past, can I still take Leukeran?

Yes, depending on when your doctor recommends starting Leukeran treatment.

Leukeran is not typically prescribed within the first 4 weeks after radiation therapy. Taking Leukeran during this time may increase your risk of bone marrow suppression, which is a possible side effect.

Bone marrow suppression means that the activity of your body’s bone marrow is reduced. All of the body’s blood cells are made in the bone marrow. If your bone marrow is suppressed or damaged, your levels of red blood cells, white blood cells, and platelets can decrease. (See “Side effect specifics” below for details about bone marrow suppression and some of the blood disorders that Leukeran can cause.)

In certain cases, your doctor may have you start Leukeran treatment within the first 4 weeks after radiation therapy. They may recommend this if you had radiation therapy to treat part of your body that is not near your bone marrow.

You can talk with your doctor if you have questions about radiation therapy and Leukeran.

If I’m over 65 years old, is Leukeran safe for me to take?

Yes, as long as your doctor prescribes it. Leukeran is in fact recommended for use in older adults because it can be easier to tolerate than similar drugs. This means it might cause fewer side effects than similar drugs.

Your doctor might prescribe a lower dosage of Leukeran than usual if you’re over 65 years old. And you might have blood tests more frequently during Leukeran treatment to monitor for side effects.

If you have concerns about taking Leukeran that are related to your age, talk with your doctor.

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

Neutropenia

Neutropenia is a common side effect that may occur during treatment with Leukeran. With neutropenia, you have low levels of certain white blood cells called neutrophils. If this condition occurs with a fever, it’s considered a medical emergency.

Neutropenia is diagnosed with lab tests. This condition doesn’t typically cause symptoms. However, it may increase your risk of getting infections.

Neutropenia is more likely to happen in people taking high doses of Leukeran. In clinical trials, Leukeran doses of 6.5 milligrams (mg) or more per kilogram (kg) of body weight in one course of therapy caused neutropenia. This typically happened when continuous dosing was prescribed. (Continuous dosing means Leukeran is given every day for a certain time period.)

You’ll have lab tests to check for neutropenia and other blood disorders during Leukeran treatment.

What you can do

Tell your doctor if you develop any symptoms of infection, especially a fever. Depending on the type of infection, symptoms may include:

  • fever
  • sweating or chills
  • sore throat
  • digestive symptoms such as nausea, abdominal pain, vomiting, or diarrhea
  • painful or increased urination
  • coughing or breathing problems
  • changes in your vaginal discharge
  • changes in your mental state

Neutropenia that occurs with a fever is a medical emergency. Call your doctor or go to the nearest emergency room if you have a temperature reading of 101°F (38.3°C) or higher, or a temperature of 100.4°F (38°C) or higher that lasts for 1 hour or more.

Seizures

Seizures have happened in people taking Leukeran. This is typically a rare side effect. You may have an increased risk of seizures if you:

  • have a seizure disorder or have had a seizure in the past
  • have had a head injury in the past
  • are taking high doses of Leukeran
  • are taking other medications that can increase the risk of having a seizure

Children who have nephrotic syndrome (a kidney disorder) are also more likely to have seizures with Leukeran treatment.

What you can do

Talk with your doctor if you have concerns about seizures while taking Leukeran. And be sure to talk with them about your seizure risk before starting Leukeran treatment.

Thrombocytopenia

Thrombocytopenia (low levels of platelets in the blood) is a common side effect that can happen during treatment with Leukeran.

Platelets are cells that help your blood clot. Having too few platelets can lead to bleeding and bruising.

Thrombocytopenia shows on lab tests, and it doesn’t always cause noticeable symptoms. You’ll be monitored for this and other blood disorders during Leukeran treatment. Possible symptoms of thrombocytopenia include:

  • nose bleeds that last for a long time
  • bleeding gums
  • bruising more easily
  • fatigue
  • heavier periods
  • a skin rash made up of red or discolored dots

What you can do

Tell your doctor if you develop any of the symptoms of thrombocytopenia listed above.

If you develop this condition, your doctor might have you stop taking Leukeran until your platelets return to typical levels. They may also give you treatments to help increase your platelet levels, such as a blood infusion.

Peripheral neuropathy

Peripheral neuropathy is a rare side effect of Leukeran. Peripheral neuropathy occurs when there’s damage to nerves that help send signals between your central nervous system and the rest of your body.

Symptoms of this condition can include:

  • a feeling of tingling or burning in your hands or feet
  • decreased feeling in your hands or feet
  • trouble with balance and coordination

What you can do

Tell your doctor if you have any of the above symptoms of peripheral neuropathy. Your doctor might prescribe medication to manage your symptoms. In some cases, they might have you stop taking Leukeran and recommend a different medication instead.

Bone marrow suppression

Leukeran has a boxed warning about a risk of bone marrow suppression (reduced activity of the bone marrow). A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

Leukeran can cause your bone marrow to produce fewer blood cells than is typical. This may cause your levels of red blood cells, white blood cells, or platelets to decrease. Low levels of these blood cells can lead to:

  • infection, which can cause varying symptoms such as fever, chills, or diarrhea
  • anemia
  • increased bleeding and bruising

Your doctor will monitor your blood cell levels with lab tests during your Leukeran treatment. This helps them monitor you for signs of bone marrow suppression and other blood cell problems.

What you can do

Tell your doctor if you develop a fever or other signs of infection while taking Leukeran, or if you seem to be bleeding or bruising more easily.

If you develop signs of bone marrow suppression or low levels of certain blood cells, your doctor may give you blood tests. They might pause your Leukeran treatment until further tests show that your blood cells have returned to typical levels. Or your doctor might recommend that you stop taking Leukeran and take a different cancer medication instead.

Cancer

Leukeran has a boxed warning about an increased risk of cancer. A boxed warning is the most serious warning from the FDA.

Although Leukeran treats some types of cancer, it can also increase your risk of developing some other types of cancer. People who have taken Leukeran for its approved uses have developed a type of cancer called acute myeloid leukemia (AML). Symptoms of this condition include:

What you can do

Tell your doctor if you develop any symptoms of AML or other cancers. They’ll recommend whether you should stop Leukeran treatment and may recommend a different cancer treatment.

Allergic reaction

As with most drugs, Leukeran can cause an allergic reaction in some people.

Symptoms can be mild or serious and can include:

  • skin rash, which can rarely be severe (see below)
  • itching
  • flushing
  • swelling under your skin, typically in your lips, eyelids, feet, or hands
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

In rare cases, the following severe skin conditions have occurred after developing a skin rash:

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 Leukeran. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Boxed warnings

This drug has boxed warnings about risks of bone marrow suppression, cancer, fetal harm, and infertility. These are serious warnings from the Food and Drug Administration (FDA).

For details about the risks of bone marrow suppression and cancer, see the “Side effect specifics” section above. And for details about the risks of fetal harm and infertility, see the “Pregnancy and breastfeeding while taking Leukeran” section just below.

Other precautions

Be sure to talk with your doctor about your health history before you take Leukeran. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. The conditions and factors to consider include:

Liver problems. Leukeran can cause liver damage. Tell your doctor if you already have liver problems before starting treatment with Leukeran. They may prescribe a lower dosage of Leukeran than is typical, or they might recommend a different medication for you.

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

Seizures. If you’ve had seizures in the past or if you have a seizure disorder, tell your doctor before taking Leukeran. Certain medications can further increase your risk of seizures if you take them with Leukeran. Be sure to tell your doctor about all of the medications you take.

Radiation therapy. If you’ve recently had radiation therapy, your doctor may recommend waiting 4 weeks after your last dose of radiation to start Leukeran treatment. If the radiation was for an area of the body that is not close to bone marrow, you might be able to start Leukeran sooner. Radiation and Leukeran both suppress (reduce) the activity of your bone marrow. Tell your doctor about any radiation treatments you’ve had before starting Leukeran treatment.

Low levels of platelets or white blood cells. Your doctor will likely check your levels of certain blood cells before starting treatment with Leukeran. If your levels of platelets, white blood cells, or other blood cells are too low, your doctor will have you wait until they improve before starting your Leukeran treatment.

Alcohol with Leukeran

There aren’t any known interactions between Leukeran and alcohol. However, drinking alcohol while taking Leukeran can increase your risk of certain side effects, such as:

If you drink alcohol, talk with your doctor about how much is likely safe for you to drink while you’re taking Leukeran.

Pregnancy and breastfeeding while taking Leukeran

Leukeran has a boxed warning about the risk of possible harm to a fetus if it’s taken during pregnancy. It also has a boxed warning about a risk of infertility in both males* and females.*

Infertility means being unable to become pregnant or cause pregnancy. Infertility caused by Leukeran may be temporary or permanent. It may show as missed periods or semen that doesn’t contain sperm.

It’s not known if Leukeran passes into breast milk. Leukeran’s use during breastfeeding hasn’t been studied in humans.

Tell your doctor if you’re pregnant, breastfeeding, or planning either before you start taking Leukeran. They’ll likely recommend a different treatment.

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

Treatment with Leukeran can cause mild and serious side effects. Talk with your doctor about side effects that are serious or bothersome.

If you’d like to learn more about Leukeran, talk with your doctor or pharmacist. They can help answer any questions you have about side effects of taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

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.