Cyclophosphamide is used to treat various types of cancer. It is a chemotherapy drug that works by slowing or stopping cell growth.

Cyclophosphamide also works by decreasing your immune system's response to various diseases. It is used to treat a certain type of kidney disease in children after other treatments have not worked.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This medication may also be used for various conditions such as lupus and multiple sclerosis.

This medication is usually given by injection into a vein by a health care professional. The dosage is based on your medical condition, weight, response to treatment, and other treatments (such as other chemotherapy drugs, radiation) you may be receiving. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During treatment with this medication, it is important that you take in more fluids than usual and pass urine often to help avoid kidney and bladder side effects. Intravenous fluids should be given with this medication. Also, ask your doctor how much fluid you should drink and how often to empty your bladder each day, and follow these instructions carefully.

Nausea, vomiting, loss of appetite, stomach ache, diarrhea, or darkening of the skin/nails may occur. Nausea and vomiting can be severe. In some cases, drug therapy may be necessary to prevent or relieve nausea and vomiting. Changes in diet such as eating several small meals or limiting activity may help lessen some of these effects. If these effects last or get worse, notify your doctor or pharmacist promptly.

Although these effects are uncommon, immediately report any pain, swelling, or redness at the injection site.

Temporary hair loss may occur. Hair growth should return after treatment has ended or may even return during treatment. However, new hair may have a different color or texture.

People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.

Tell your doctor right away if you have any serious side effects, including:

• signs of kidney or bladder problems (such as change in the amount of urine, pink/bloody urine)
• mouth sores
• joint pain
• stopping of menstrual periods
• existing wounds that are slow healing
• black/bloody stools
• signs of liver problems (such as stomach/abdominal pain, yellowing eyes/skin, dark urine)
• mental/mood changes
• muscle weakness/spasm

This medication may rarely cause very serious effects on the heart, especially when used in high doses, or in combination with radiation treatment or certain other chemotherapy drugs (such as doxorubicin). Get medical help right away if you develop:

• chest pain
• jaw/left arm pain
• trouble breathing
• irregular heartbeat
• symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain)

This medication decreases bone marrow function, an effect that may lead to a low number of blood cells such as red cells, white cells, and platelets. This effect can cause anemia, decrease your body's ability to fight an infection, or cause easy bruising/bleeding. Tell your doctor right away if you develop any of the following symptoms:

• unusual tiredness
• pale skin
• signs of infection (such as sore throat that doesn't go away, fever, chills)
• easy bruising/bleeding

Cyclophosphamide may lessen the chance of having children in both men and women. Sterility is usually temporary with this medication, but can be permanent in some cases. Consult your doctor for more details.

Although cyclophosphamide is used to treat cancer, in some patients it may increase the risk of developing another form of cancer, sometimes months to years after treatment. Consult your doctor for more details. It is important to be closely monitored by your doctor during treatment. You should also see your doctor regularly after treatment is finished. Tell your doctor right away if you develop:

• unusual growths or lumps
• swollen glands
• unexplained or sudden weight loss
• night sweats
• pain in the pelvis
• painful or frequent urination

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using cyclophosphamide, tell your doctor or pharmacist if you are allergic to it; or to other chemotherapy drugs (such as busulfan, chlorambucil); or if you have any other allergies. This product may contain inactive ingredients (such as alcohol), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• decreased bone marrow function (such as anemia, leukopenia, thrombocytopenia)
• liver disease
• kidney disease
• difficulty urinating (for example, due to blockage)
• surgery to remove your adrenal glands

Cyclophosphamide can make you more likely to get infections or may make current infections worse. Stay away from anyone who has an infection that may easily spread (such as chickenpox, COVID-19, measles, flu). Talk to your doctor if you have been exposed to an infection or for more details.

Tell your health care professional that you are using cyclophosphamide before having any immunizations/vaccinations. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

To lower the chance of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Children may be more sensitive to the side effects of this drug, especially possible infertility later in life.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using cyclophosphamide. Cyclophosphamide may harm an unborn baby. Your doctor should order a pregnancy test before you start this medication. Women using this medication should ask about reliable forms of birth control during treatment and for 1 year after the last dose. Men using this medication should ask about reliable forms of birth control during treatment and for 4 months after the last dose. If you or your partner becomes pregnant, talk to your doctor right away about the risks and benefits of this medication.

This drug passes into breast milk and may harm a nursing infant. Breastfeeding is not recommended while using this drug and for 1 week after the last dose. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• azathioprine
• etanercept
• turmeric (curcumin)
• voclosporin

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Lab and/or medical tests (such as complete blood counts, urine tests) should be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule.

Consult the product instructions and your pharmacist for storage details. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).